- Open Access
Lymphopenia in Cancer Patients and its Effects on Response to Immunotherapy: an opportunity for combination with Cytokines?
Journal for ImmunoTherapy of Cancer volume 7, Article number: 85 (2019)
Quantitative lymphocyte alterations are frequent in patients with cancer, and strongly impact prognosis and survival. The development of cancers in immunosuppressed patients has demonstrated the contribution of different T cell populations, including CD4+ cells, in the control of cancer occurrence.
Whereas absolute numbers of neutrophils, platelets and red blood cells are routinely monitored in clinic following treatments, because of possible short-term complications, absolute lymphocyte counts (ALC), their subpopulations or diversity (phenotype, TCR) are rarely analyzed and never used to choose therapy or as prognostic criteria. The recent identification of immune checkpoint inhibitors (ICPi) as powerful therapeutic agents has revitalized immunotherapy of cancer in a broader group of diseases than anticipated. The status of the immune system is now recognized as an important biomarker for response to these novel treatments. Blood ALC values, along with tumor infiltration by CD8+T cells, and ICPi and ICPi-ligand expression, are likely to be a potential marker of sensitivity to anti-ICPi therapy.
In this article, we review the current knowledge on the incidence and significance of lymphopenia in cancer patients, and discuss therapeutic strategies to restore lymphocyte numbers.
The progression of solid tumors is associated with a variety of strategies developed by cancer cells to escape the immune response (for review :). The development of treatments with antibodies (mAb) targeting ICPi constituted an important breakthrough leading to increased patient survival in several cancers such as melanoma, lung, kidney or bladder. ICPi blockade involves mAbs targeted against cytotoxic T-lymphocyte associated protein 4 (CTLA-4), programmed death receptor 1 (PD-1) or its ligand (PD-L1) which have all been demonstrated to inhibit T cell activation and favor T cell exhaustion or the development of regulatory T cells (Tregs). The use of ICPi blockers modulate the interaction between T lymphocytes and tumor cells or macrophages, thereby favoring the re-induction of the “natural” function of T cell populations in the tumor environment leading to a durable clinical response. However, even in cancers where these ICPi demonstrated an overall survival (OS) benefit, only 20 to 40% of patients will benefit from treatment, hence highlighting the need to identify strategies to improve efficacy. As lymphocytes have been recognized as major actors in the fight against tumor progression in several human tumors, we review herein the role of lymphopenia as a surrogate marker of initial resistance to immunotherapy and discuss therapeutic strategies to restore lymphocyte numbers and to increase the response rate of patients treated with ICPi mAbs.
Tumor cells induce immune system dysfunctions
In murine models and in humans, the risk of tumor development is increased in the context of immunosuppression [2, 3] demonstrating the concept of tumor immuno-surveillance wherein the immune system is involved in controlling or eliminating transformed cells. Alterations in anti-tumor immune responses have been widely described since the 1980’s.
Immune infiltrates in primary tumors
A recent meta-analysis of 20 different cancer types has established that the density and the composition of the immune infiltrate are important for tumor progression .
A high density of CD8+ T effectors in most tumors correlates with longer disease free survival (DFS) and OS . In contrast, the accumulation of myeloid-derived suppressor cells (MDSC) , type-2 macrophages (M2-MΦ) ) or Tregs (for review ), as well as the production of suppressive cytokines and metabolites favor an immunosuppressive environment and tumor progression.
Among these suppressive cells, Tregs are selectively recruited in the tumor environment through the CCL22/CCR4 axis [8,9,10]. Compared to other T cells, Tregs have an activated phenotype (ICOS, GARP, CD39, GITR, HLA-DR) [9, 11,12,13] and expand in situ through ICOS/ICOS-L interaction with tumor-infiltrating plasmacytoïd dendritic cells or tumor cells [11, 13,14,15,16,17].
Quantitative and functional alterations in the peripheral blood
The existence of peripheral immune alterations in cancer patients was shown for the first time in the mid-1970’s by Bone and Lauder  in gastrointestinal tumors. Lymphopenia has been observed in more than 20% of patients with advanced disease and only 3% with localized disease [19,20,21] in several tumor types (pancreas, melanoma, Non-Hodgkin’s lymphoma (NHL), breast cancer (BC), sarcomas). Moreover, an increased number of circulating neutrophils, a hallmark of inflammation, is observed in patients with solid tumors and is combined with an increased neutrophil-to-lymphocyte ratio (NLR) (for review :).
Lymphopenia may affect all or only some of the T or B lymphocyte subpopulations. CD4+ lymphopenia is key in the clinical evolution of HIV patients [23,24,25], is common in many advanced cancer patients with pancreatic cancer, melanoma, NHL, BC, sarcomas or hepatocellular carcinoma (HCC) [19,20,21].
Furthermore, modulation of other blood subpopulations have been described such as increased frequency of Tregs (for review [7, 26]), Th17 cells , MDSC , or PD-L1+ T cells . Most of these alterations were associated with poor prognosis [26, 30], but are not directly correlated with lymphopenia.
While CD4 lymphopenia is mostly detected in advanced or metastatic stages, functional impairment of immune cells (NK, monocytes, memory CD4+ and CD8+ T cells) can be detected in patients with localized primary tumors (BC, colon carcinoma, HCC) [31,32,33,34,35]. Primary tumor-derived factors alter blood monocytes that are unable to differentiate into M1-MΦ (Ramos submitted) or functional Mo-DC [36,37,38].
Clonality, diversity and magnitude of the adaptive immune response
Each T cell expresses a TCR allowing its specific activation by a unique antigen presented in the context of the major histocompatibility (MHC) complex. Thus, T cell populations must express a broad polyclonal TCR repertoire to confer immune protection against infectious agents and malignant cells . Recent evidences indicate that somatic mutations are the basis for the generation of potential neo-antigens recognized by tumor-infiltrating T lymphocytes (TIL) [40, 41]. A strong TCR diversity is required to generate a response against neo-epitopes and recent studies [42,43,44,45,46,47,48] suggest that broadening of the TCR repertoire diversity could favor tumor control.
Since the 1990’s, PCR-based technologies enabled the quantification of TCR diversity at the mRNA and genomic levels. Numerous data have reported a restriction of the TCR diversity with the appearance of an oligoclonality in TILs in comparison to peripheral T lymphocytes (for review ). In metastatic BC patients, peripheral blood TCR diversity is not homogenously represented and diversity is significantly reduced in comparison to healthy donors  but not necessarily associated with lymphopenia, thereby demonstrating the importance of combined scores to characterize T cell alterations .
Lymphopenia is associated with increased cancer incidence
A meta-analysis performed in two immuno-compromised patient populations (HIV-infected and transplanted patients)  have shown a higher incidence of cancers due to infectious or viral causes. Other studies [52, 53] in transplanted patients reported a higher incidence of virus-induced cancers (Kaposi's sarcoma, NHL and HL) as well as tumors without established viral etiology such as head and neck carcinomas and melanomas. Moreover, CD4+ T cell lymphopenia in patients with Sjögren's autoimmune syndrome  or idiopathic CD4+ lymphopenia [55, 56] is associated with an increased risk of cancer. Accordingly, the restauration of immune functions in AIDS patients thanks to highly active anti-retroviral therapies (HAART) was associated with a strong reduction in the incidence and the progression of these cancers [57, 58].
Immune deficiency is therefore consistently associated to increased frequency of certain cancer types.
Impact of lymphopenia on tumor evolution
Lymphopenia is correlated with patient survival and toxicity of chemotherapy
Lymphopenia observed in advanced disease [19,20,21, 50, 59,60,61,62,63,64] correlates with patients’ performance status (PS) as well as with specific unfavorable prognostic factors .
Studies performed by our group and others, including over 3,000 patients with advanced cancers, have shown that regardless of the histological subtype and treatment, global and CD4+ lymphopenia are powerful independent predictors of risk of high grade toxicity associated with chemotherapy including febrile neutropenia (FN) [59, 64, 66, 67], severe thrombocytopenia requiring platelet transfusion , severe anemia requiring red blood cells (RBC) transfusion [61, 62] and increased risk of early death after chemotherapy [19,20,21, 63].
Randomized clinical trials have demonstrated the ability of prophylactic recombinant G-CSF (Filgrastim, ELYPSE-2) and EPOα (ELYPSE-4) to reduce FN and RBC transfusion requirements, respectively  in these high risk lymphopenic patients.
Prognostic Value of lymphopenia for PFS and OS
A peripheral lymphopenia impacts on patient PFS and OS in many advanced solid tumors (Table 1). In breast and ovarian carcinomas, NHL, DLBCL, T-cell lymphomas (PTCL, PTCLU), follicular lymphoma [69, 70], sarcomas and colon carcinoma, a global (<1000/mm3) or severe (<700/mm3) lymphopenia detected before treatment [65, 66, 71,72,73,74, 88,89,90, 92,93,94], early after chemotherapy treatment (5 or 15 days) [19, 75, 91] or after radiotherapy (RT) (for review :) is associated with a worse PFS and OS.
Other studies using different thresholds of lymphopenia from moderate (<1500/mm3) to severe (<600/mm3), report similar results in recurrent desmoid tumors , pancreatic tumors , renal cell carcinoma (RCC) , diffuse large B cell lymphomas (DLBCL) [79, 80], Hodgkin’s disease [81, 82], and HCC .
Scores combining different biological parameters have also been evaluated for their capacity to predict outcome. Inflammatory markers, such as the NLR, the monocyte-to-lymphocyte ratio (MLR), and the platelet-to-lymphocyte ratio (PLR), used as markers of systemic inflammation, are associated with poor outcomes in several malignancies [84, 85]. An elevated NLR, which reflects a combination of increased number of neutrophils and/or lymphopenia, is associated with worse outcome in many solid tumors, both in early and advanced stages . Moreover, a high serum lactate dehydrogenase level (LDH)-to-ALC ratio predicts a poor intra-tumoral immune response and reduced survival in DLBCL patients .
Altogether, lymphopenia is consistently reported as an adverse prognostic factor for PFS or OS in a variety of tumors. In first line metastatic BC patients  patients with both lymphopenia and low TCR diversity (16.4% of the cohort) before any treatment have an increased risk of early death after chemotherapy . All lymphocyte compartments are quantitatively altered . While NK cell and CD8+ T cell or B cell lymphopenia correlate poorly with OS, CD4+ lymphopenia and severe lymphopenia (<200/mm3) strongly impact patient survival with respectively 40% and 90% reduction of the median OS or PFS. In multivariate analyses, CD4+ lymphopenia is an independent poor prognosis factor for OS in several cohorts of advanced BC (1st line and > 2nd line) , and other solid tumors (NHL, myelomas and sarcomas) . Furthermore in Ewing sarcoma  and osteosarcoma patients , early ALC recovery after chemotherapy treatment predicts better outcome. Conversely in NHL, altered CD8+ T cell numbers (<200/mm3) correlate with a poor prognosis  whereas CD4+ lymphopenia (<500/mm3) does not. This might be related to the role of CD4+ T cells as helpers for B cell tumor development.
Altogether, these data demonstrate the negative prognostic value of CD4+ lymphopenia and its significance as a predictor of non-response to chemotherapy suggesting the important role of CD4+ T cells in controlling tumor progression and/or development of opportunistic infections in cancer patients.
Lymphopenia is also favored by radiotherapy, chemotherapy and targeted therapies
Although, localized RT treatment could favor anti-tumor immunity through abscopal effects , RT also strongly favors lymphopenia (for review ). Indeed, in addition to affecting TILs, RT also negatively impacts circulating lymphocytes transiting through the irradiated field favoring lymphopenia. In this context, RT of tumors near lymphopoïetic sites will also contribute to lymphopenia. Moreover, RT-associated lymphopenia depends on the radiation modality with RT-target volume playing an important role . The reduction of radiation doses using either proton beam therapy (PBT) that spares surrounding tissue from radiation or reduction of the duration of exposure using either short course radiation with stereotactic body RT (SBRT) or hypo-fractionated schedule will mitigate normal tissue exposure reducing the risk of severe lymphopenia [97, 98]. Additionally the impact of RT also depends on the environment since a cancer-related inflammatory state, as shown by neutrophilia, before radiation is correlated with an increased susceptibility to RT-induced grade-4 lymphopenia .
Cyclophosphamide, cisplatin, methotrexate, and taxanes are among the most powerful chemotherapies inducing lymphopenia. Treatment of hematological tumors with fludarabine strongly reduces CTL numbers [100, 101]. Of interest, metronomic treatment with cyclophosphamide has proven its capacity to limit lymphopenia by selectively damaging Tregs , thus mitigating immunosuppression and promoting anti-tumor T cell immunity.
Several therapies targeting oncogenic signaling pathways or molecular abnormalities also induce lymphopenia, including all patients receiving mTOR inhibitors  and 20% of patients treated with tyrosine-kinase receptor inhibitors targeting VEGFR or PDGFR . Intriguingly, whereas MEK inhibitors do not alter ALC, among BRAF inhibitor treatments, vemurafenib  but not dabrafenib [105, 106] induces lymphopenia affecting principally CD4+ T cells that may either result from a change in their compartmental distribution in the tumor  or secondary lymphoid tissue or from an absolute lymphopenia due to direct effect of BRAF inhibition on T cells.
The combination of chemotherapy and immunotherapy may also induce severe lymphopenia. For example, the treatment of DLBCL by the combination of an alkylating agent, and an anti-CD20 antibody, induces a CD4+ T cell lymphopenia in 66% of cases, that is reversed upon treatment discontinuation while anti-CD20-induced B cell lymphopenia persists .
Several studies have shown that naïve CD4+ T cell regeneration requires an active thymic function present in children, and is less effective in adults and elderly patients while CD8+ T cell recovery is faster and less dependent on thymic activity [109,110,111].
Putative mechanisms contributing to cancer patient lymphopenia
Several mechanisms may account for lymphopenia detected in metastatic cancer patients; i) destruction of lymphocytes induced by tumor cells expressing pro-apoptotic ligands , ii) reduced capacity of lymphocytes to respond to TCR stimulation due to an altered expression of the ζ chain of the TCR , iii) a high proportion of CTLA-4-expressing Tregs favoring immunosuppression  or iv) activation induced cell death (AICD) . In the tumor environment, PDL-1 expressed on tumor cells or macrophages (for review ) may lead to reduced TIL proliferation and survival  that could have a systemic impact.
However, the reduction of naive CD4+ T cell numbers suggests an alteration of the generation of new naive CD4+ T lymphocytes, which may result from i) a reduced thymic function, ii) a defect in production of homeostatic cytokines (IL-7, IL-15, IL-2) or of their receptors (IL-7Rα) or iii) an impairment in recruitment of cells generated in the thymus to the periphery via a reduction in plasma levels of chemokines (CCL22) .
It remains to be determined whether lymphopenia is associated with somatic tumor characteristics or to constitutional patient characteristics, or both.
Therapies to restore a physiological number of lymphocytes in the peripheral blood
The identification of treatments able to restore a physiological number of T cells is of major importance. Different immunotherapy treatments have been evaluated in HIV “immune non-responders” patients, but also in patients with virus-induced (HCV) chronic hepatitis, idiopathic CD4+ lymphopenia, and hematological malignancies treated with HSCT, or in chemotherapy-treated advanced cancer patients.
IL-2, IL-7 and IL-15 are three cytokines playing a role in the development, proliferation and survival of T cells that have been evaluated to restore lymphopenia. IL-2 binds to its high affinity receptor composed of three subunits including IL-2Rα (CD25), IL-2Rβ (CD122), and IL-2 receptor γ chain (CD132) common to multiple cytokines (IL-2, IL-4, IL-15, IL-7, IL-9 and IL-21). IL-15 signals through a hetero-trimeric receptor involving CD132 and CD122 shared with IL-2 and a third receptor subunit, specific for IL-15 (IL-15Rα). IL-7 signals through a heterodimer that consists of two chains: IL-7Rα (CD127), shared with thymic stromal lymphopoietin (TSLP), and CD132.
IL-2, a key cytokine responsible for both CD4+ and CD8+ T cell proliferation (for review ), has been evaluated in HIV patients with severe CD4+ lymphopenia. However, despite a marked increase in absolute CD4+ T cell number, no clinical benefit was observed [119, 120]. The proportion of Tregs among CD4+ T cells  was increased as i) IL-2 delivers signals essential for thymic or peripheral Tregs differentiation  and ii) Tregs expressing high CD25 levels have a competitive advantage over other T cell subpopulations .
The injection of high doses of IL-2, one of the first immunotherapies approved by the FDA as a single agent for treatment of metastatic melanoma and RCC, induced significant hematological toxicities including thrombocytopenia and lymphopenia [123, 124]. Increased perforin+ NK cells and activated CD8+ T cell numbers were described in the periphery and within the tumor mass in most treated patients demonstrating an activation of the anti-tumor immune response, but this remained transient and was not always correlated with tumor regression or clinical response  probably due to the strong concomitant amplification of Tregs [126, 127].
The design of mutant IL-2 molecules (IL-2v) provides an alternative for improving the biological activity of IL-2. Several groups have designed IL-2v that bind conventionally on CD122/CD132 but have reduced affinity to IL-2Rα which prevents Tregs expansion [128,129,130].
IL-15 shares structural similarities with IL-2 and plays a central role in controlling the life and death of NK cells and memory CD8+ T cells (for review ). Although IL-15 and IL-2 share a number of functions on T cell subpopulations, B cells and NK cells, in many adaptive immune responses, they have distinct and often conflicting effects. Unlike IL-2, IL-15 is not required for the maintenance of Tregs and in contrast to IL-2 that promotes AICD, IL-15 reduces apoptosis of activated T cells . IL-15 promotes memory CD8+ T cells survival and plays a major role in maintaining high affinity and sustainable T cell responses against pathogens .
These functional differences may partly result from the source of cytokine production since IL-2 is produced by T cells, NK and NKT cells whereas IL-15 is mainly produced by stromal cells, DC, monocytes/macrophages and endothelial cells. Additionally, these cytokines differ in terms of mode of action, since IL-15 associated to IL-15Rα at the surface of a producer cell interacts with CD122/CD132 on T cells to deliver an activation signal at the immunological synapse by trans-presentation. On the other hand, IL-2, which is secreted, has more distant and bystander biological effects. Ten days treatment of macaques rhesus with IL-15 strongly increased NK cell numbers and induced a huge amplification of circulating effector-memory CD8+ T cells  whereas memory CD4+ T cells were less affected and Tregs underwent weak stimulation .
Several ongoing clinical trials are evaluating the impact of rhIL-15 in advanced cancer patients. A first pilot study reported the capacity of rhIL-15 to drastically increase NK cells, Tγδ and CD8+ T cell numbers that return to baseline two weeks after treatment completion . However IL-15 treatment causes fever and reduced blood pressure , while also inducing the expression of ICPi such as PD-1 and the immunosuppressive cytokine IL-10 secreted by CD8+ T cells . The IL-15 super-agonist (ALT-803), a (N72D) IL-15/IL-15Rα/IgG1-Fc complex with potent agonist function to the CD122/CD132 dimers  and increased half-life  is currently being evaluated in clinical trials in ovarian cancer (NCT03054909), multiple myeloma (NCT02099539) and AML (NCT02989844) without any efficacy result published yet.
IL-7 is a non-redundant cytokine secreted by fetal liver cells, bone marrow and thymic stromal cells, as well as epithelial cells (enterocytes, keratinocytes) and follicular dendritic cells (for review ). IL-7 is essential for T cell generation as IL-7- or IL-7R-deficient mice as well as IL-7Rα mutant patients with severe combined immunodeficiency (SCID) do not generate mature T lymphocytes [142, 143]. In these situations, thymocytes are blocked at an early stage of differentiation and thymic cellularity is considerably reduced . Moreover, IL-7 is a key player in the regulation of peripheral T cell homeostasis  and is involved in survival, proliferation, differentiation, and metabolism of peripheral T lymphocytes . Thus IL-7 is a potent therapeutic candidate for immune reconstitution.
IL-7 has been successfully tested in various immune reconstitution models. In mouse models of chemotherapy-induced lymphopenia, IL-7 accelerates CD4+ and CD8+ T cell repopulation in spleen and lymph nodes . An immune reconstitution is observed in murine and baboon allogeneic HSCT models treated with IL-7 [148, 149] and has recently been evaluated to counteract IFNα-induced lymphopenia  and treat SIV infected monkeys . In the preclinical models evaluated, IL-7 injection does not induce the acute inflammatory cytokine release observed with IL-2 . In preclinical tumor models, IL-7 alone does not allow the development of anti-tumor immune response yet amplifies a response induced by vaccination or adoptive T cell transfer .
rhIL-7 has been evaluated in the clinic for the treatment of severe lymphopenia in “immune non-responder” HIV patients, post-HSCT transplanted patients, patients with idiopathic lymphopenia, and advanced cancer patients post-chemotherapy and has demonstrated an effect on T lymphocytes in terms of increased cell counts, quality and TCR diversity [44,45,46,47,48]. To date, fifteen clinical trials evaluating the subcutaneous injection of rhIL-7 with variable dosing schedules have been recorded worldwide. So far, the clinical data show that rhIL-7 is well tolerated (for review [153, 154]).
Treatment is associated with early but transient T cell depletion that could result from a rapid migration of T cells from the blood to various organs (glands, intestine, skin) as shown in monkey studies . This period is followed by a peripheral CD4+ and CD8+ T cells expansion in all treated patients [44,45,46,47,48] for a long period (> 10 months).
rhIL-7 injections increase memory but also naive T cells  that partly result from the blood margination of recent thymic emigrants (CD31highTREC+) reflecting thymic reactivation. CD4+ T cells generated are conventional T cells with a detectable helper function and Treg counts are decreased . Treatment with rhIL-7 also promotes the generation of TEM and TCM, of importance for a long-term protection  and amplifies T cell diversity [157, 158], including in advanced cancer patients .
The Phase-2a ELYPSE-7 clinical trial (NCT01368107), a double-blind study randomizing recombinant IL-7 (CYT107) against placebo promoted by our institution in collaboration with Cytheris demonstrated that one cycle of CYT107 partially restored T cell pools in lymphopenic cancer patients, increasing both naïve and memory CD4+ and CD8+ subsets without altering their functional capacities  even during chemotherapy treatment. This effect was transient over time thus repeated CYT107 are required to induce a sustained increase in T cell subsets as reported by Thiébaut et al. in HIV-infected patients, underlining the importance of repeated cycles of IL-7 for long-term CD4+ T cell response . More recently, a NCI study (NCT00923351) reported restoration of CD4+ T cell counts by CYT107 treatment in pediatric sarcoma patients treated by a combination of standard antineoplastic therapy followed by autologous lymphocytes and tumor lysate/KLH-pulsed dendritic cell vaccinations .
Overall, IL-7 is expected to broaden the amplitude of the response against malignant cells that escape the immune system by mutation and immuno-editing and should help metastatic cancer patients to restore TCR repertoire diversity for improved anti-tumor immune response.
Lymphopenia, other peripheral biomarkers and ICPi treatment
Whereas, modulation of immune cell composition in solid tumor environment during anti ICPi treatment has been widely described (for review ), the changes in periphery remain less well characterized. Retrospective peripheral blood immuno-monitoring studies were conducted on small cohorts to determine if the number and quality of circulating immune cells might affect their efficacy.
Lymphopenia and other T cell biomarkers
ICPi (PD-1, TIM-3, CTLA-4) expression by TILs in solid tumors known to be involved in the inhibition of T cell activation/proliferation could participate to peripheral lymphopenia. The therapeutic activity of anti-CTLA-4 and anti-PD-1/L1 Abs (for review ) may, in part, act through the restoration of normal numbers of circulating lymphocytes.
Interestingly, baseline lymphopenia  or increased ALC 2 to 8 weeks [166,167,168] after the first ipilimumab injection have been reported as possible biomarker candidates for improved outcome. Moreover, in advanced melanoma patients with severe lymphopenia, tremelimumab rapidly restores the effector and memory CD4+ and CD8+ T-cell pool and TCR-dependent T-cell proliferation whereas NK cell lymphopenia is not affected .
Low ALC also impacts efficacy of anti-PD-1/ -L1 as lymphopenia is a worse prognosis factor both at baseline [170,171,172] and after two to three months of treatment [170, 172].
T cell subsets
T cells are the main effector cells of ICPi treatment. Retrospective analysis of blood T cell subsets in anti-CTLA-4-treated melanoma patients revealed that a high proportion of Tregs before treatment was associated with better survival [166, 173]. Their constitutive expression of CTLA-4 could make them the preferred targets of ipilimumab. Anti-CTLA-4 efficacy has also been associated with reductions in naïve T cells  and increase in melanoma-reactive CD8+ cytotoxic T cells . Finally, ipilimumab treatment resulted in consistently durable (3- and 6- months) increased proliferation of both CD4+ and CD8+ T cells . Likewise, screening of anti-PD-1 treated melanoma patients’ blood by high dimensional clustering, identified the increase of a subset of CD4+ TCM in long-term survivors, but not in non-responders .
Expression of ICP/ICP-L on T cells
High PDL-1 expression on T cells (CD4+ and CD8+) was associated with worse PFS and OS after anti-CTLA-4 treatment of melanoma  and might, therefore, be a mechanism for tumor immune escape to anti-CTLA-4 treatment. Increased blood frequency of ICOS-expressing CD4+ and CD8+ T cells which comprise a population of effector T cells [178,179,180,181] is considered as a reliable biomarker of clinical response to anti-CTLA-4. Moreover, detection in blood of high risk resected melanoma of CD137-expressing CD8+ T cells, that could relate to tumor antigen-specific T cells, was significantly associated with a lack of relapse after adjuvant ipilimumab+nivolumab therapy .
Monitoring of these different populations could potentially be helpful to predict clinical response to anti-ICPi therapies.
Data on the impact of baseline blood TCR diversity on anti-ICPi efficacy are scarce, based on small cohorts and not yet consistent. In metastatic urothelial cancers, pretreatment peripheral blood TCR clonality below the median was associated with better response to anti-ICPi treatments but did not correlate with mutation load . In anti-PD-1/L1 treated patients a high baseline peripheral TCR diversity correlated with improved survival in urothelial cancer  but not in melanoma . Also, in anti-CTLA-4 treated melanoma patients, one study reported that high baseline TCR diversity correlated with clinical benefit (n=12) ) but not the other (n=21)  suggesting the need of larger cohorts to confirm this.
Moreover, immunotherapeutic interventions can alter the blood TCR repertoire. Importantly, increased TCR repertoire diversity is induced upon CTLA-4 blockade in blood of patients with melanoma and prostate cancer [186, 187] and associated with improved clinical outcomes .
Myeloid cells and other circulating biomarkers
A recent meta-analysis in 738 patients  reported that high baseline NLR is associated with a reduced response rate to ICPi treatment (ipilimumab, nivolumab or combination) in several solid malignancies (melanoma, non small cell lung carcinoma (NSCLC), genitourinary cancer). Moreover, high post-treatment NLR correlated with an increased risk of relapse or death in multivariate analysis in anti-PD-1-treated NSCLC patients [189,190,191]. The addition of NLR to the previously described prognostic score based on objective variables (LDH, serum albumin, number of metastatic sites) might help to better select patients for immunotherapy phase-I trials.
The number of immunosuppressive MDSC has been found to negatively affect incidence of response to anti-CTLA-4 treatment and patient OS [166, 168, 192]. In contrast, conflicting data exist for their impact on anti-PD-1 efficacy with negative correlation with OS  or no impact . In contrast in this latter study, CD14+CD16negHLA-DRhigh classical monocytes counts were strongly correlated with good outcome.
Eosinophils have important functions for tumor surveillance and were described as effectors for tumor rejection in animal models . In patients treated with ipilimumab, high baseline absolute eosinophil count correlated with improved OS [166, 196] and early increase of eosinophil counts during treatment was associated with improved clinical responses [165, 192, 196, 197]. Similar observations were recently reported for treatment with anti-PD-1 in melanoma patients  but not in NSCLC patients .
Seric soluble parameters
Soluble serum biomarkers might also correlate with clinical benefit of ICPi treatment. High levels of the soluble form of PD-L1 (sPD-L1) in plasma represent a poor prognosis factor in various solid tumors (RCC, HCC, NSCLC, gastric cancer and B cell lymphoma) suggesting either a high tumor burden or that sPDL-1 interact with PD-1 and inhibits T cell function. Moreover, high pre-treatment levels of sPDL-1 were associated with increased likelihood of progressive disease in melanoma patients treated by CTLA-4 or PD-1 blockade . Furthermore, detection of soluble ligands of NKG2D (sNKG2DL) in the serum of cancer patients was inversely correlated with NK and T cell activity although they were also correlated to advanced stages of the disease with an overall negative impact on patient survival [199, 200]. In melanoma patients undergoing anti-CTLA-4 or anti-PD-1 mAb therapy, the absence of sMICA and sMICB in post-treatment serum was significantly associated with improved OS . Furthermore, high pre-treatment serum levels of sCD25 were shown to be associated with shorter OS in anti-CTLA-4-treated patients .
Correlation between blood and tumor biomarkers
Several biomarkers of response to ICPi blockade have been characterized in the tumor environment (for review ). The tumor mutation burden, microsatellite instability, defects in DNA repair machinery are indicative of hypermutation that would increase neo-antigens and neo-antigen density predict response to ICPi blockade. Moreover, intratumoral biomarkers indicative of an inflamed phenotype such as i) PD-L1 expression, ii) inflammatory gene signature, iii) T cell infiltration, iv) TCR diversity and v) cytokine production have also been related to ICPi blockade efficacy. Finally, the microbiome and the germline genetics characterizing the host environment beyond the tumor microenvironment also impact on efficacy of ICPi.
A limited number of publications correlate peripheral blood biomarkers with tumor biomarkers and response to ICPi treatment. Huang et al recently developed a “reinvigoration score” by relating changes in circulating exhausted CD8+ T cells to tumor burden that predicts anti-PD-1 response  that could be partly explained by TCR clonotypes shared by exhausted-blood CD8+ T cells and TILs, although immune cell functions within the tumor environment markedly differ from those in blood. Another study  reported an association between a high circulating CD4+ and CD8+ TCM/TEff ratio and tumor inflammation in melanoma and NSCLC patients, as well as increased PDL-1 expression in the tumor and longer PFS in response to nivolumab treatment in NSCLC patients.
Combined therapies to increase ICPi treatment efficacy
Overall, in lymphopenic patients, the recovery of normal ALC is associated with anti-ICPi responses. Besides the current strategies exploring combination of different ICPi antagonists or with ICP activator agonists (OX40, 4-1BB, ICOS), approaches aiming to increase the T cell pool and its diversity should be considered.
Combination with chemotherapy
An ongoing clinical trial from our institution (NCT03139851) is currently investigating, in lymphopenic patients with metastatic BC, the combination of metronomic doses of cyclophosphamide and anti-PD-1 with the objective to avoid chemotherapy-induced lymphodepletion, reduce the number and functionality of immunosuppressive Tregs , favor the reactivation of existing tumor specific T cells with anti-PD-1, and possibly increase the total T cell number and their TCR diversity.
Combination with radiotherapy
Recent experiments suggest that at least one mechanism of radiation-induced tumor control is the abscopal effect involving the stimulation of the adaptive immune system by tumor neo-antigen release following RT (for review ). Robust preclinical data support the combination of SBRT, that reduces the risk of lymphopenia [97, 98], with ICPi blockade administered simultaneously or sequentially in order to stimulate the adaptive immune system, with further amplification by systemic ICPi therapy [205,206,207,208]. The few clinical data available on this topic combining anti-CTLA-4 treatment with RT suggest better outcomes . However, tumors associated with a high inflammatory state might be excluded from these combined strategies because of increased risk of severe RT-induced lymphopenia . RT delivery prior to ICPi may release antigens, recruit T-cells and help to increase TCR repertoire diversity, this phenomenon being amplified by ICPi treatment.
Combination with TIL therapy
In contrast to the negative role of lymphopenia on efficacy of ICPi blockade, efficacy of TIL therapy is improved by prior lymphodepletion . This lymphodepletion is thought to improve the effector function of TILs by i) depleting endogenous Tregs, ii) reducing the number of endogenous lymphocytes competing with the transferred TILs for use of IL-7 and IL-15 produced by non-lymphoid sources in response to lymphopenia  and iii) generating “physical space” for the infusion product. TILs may also be used in combination with ICPi to overcome the existing lymphopenia. The feasibility of combined treatment with ipilimumab and standard TIL therapy was recently demonstrated in a small cohort of metastatic melanoma patients  with response rates (38.5%) similar to those observed in other TIL trials.
Combination with cytokines
In vitro culture of purified human T cells with recombinant hIL-2 and hIL-15 strongly enhances the expression of PD-1 whereas it remains mild in presence of rhIL-7 [138, 212]. In agreement, in murine tumor models, IL-7 reduces PD-1 expression on activated CD8+ T cells favoring their revitalization . In this context, these cytokines are currently evaluated in combination with anti-ICPi therapies.
Therapeutic strategies combining high dose of rhIL-2 (HD IL-2) and anti-PD-1 are being evaluated in clinical trials in melanoma (NCT03476174) and RCC (NCT02964078, NCT02989714). Even if recent data support the efficacy of HD IL-2 , its use may favor development of toxicities but also favors the expansion of T cell subsets other than Tregs. The replacement by IL-2v could circumvent both toxic effects and Tregs expansion due to its poor binding on IL-2Rα. Moreover, immuno-cytokines such as anti-CEA-IL-2v will target the delivery of IL-2v within the tumor environment expressing CEA antigen therefore reducing its systemic toxicity and favoring T cell expansion at the site of tumor response. Preclinical results in the MC38 model demonstrate that CEA-IL2v combined with anti-PD-L1 therapy yields greater antitumor efficacy than the respective monotherapies or the combination with an untargeted control immuno-cytokine .
IL-15 is currently being evaluated in combination with anti-CTLA-4 or anti-PD-1 antibodies or their combination in refractory solid tumors (NCT03388632). In parallel, IL-15 super agonist (ALT-603) combined with anti-PD-1 therapy is being assessed in metastatic non-small cell lung cancers (NCT0322866). No efficacy result has been published so far.
For IL-7, despite promising clinical impact in a randomized study , no clinical trial is investigating combination of anti-ICPi therapy and IL-7. Of importance, recent data in murine bladder tumors report that efficacy of CTLA-4 and PD-1 blockade combination relies on the interdependence between IL-7 and IFNγ signaling in T cells as the lack of either pathway abrogates therapeutic effects .
The scientific community is hoping a solution will be found to evaluate the promising combination between ICPi and IL-7.
As reported in this review, the immune system is quantitatively and qualitatively altered in a multimodal manner in cancer patients in the tumor environment itself as well as in the peripheral blood favoring the evasion of tumor cells from the immune system. Peripheral lymphopenia, pre-existing or induced by therapies in more than 20% of patients with metastatic solid tumors strongly impacts their survival. Although CD4+ lymphopenia is a powerful marker of reduced survival, its causes remain uncertain and need to be better investigated (tumor or host origin, inter-relation with TILs,…). Despite its major impact on survival, lymphopenia has not routinely been used to select candidates in anti-CTLA-4 and PD-1 immunotherapy protocols until recently. This emphasizes the importance in future immunotherapy clinical trials to analyze the combination of CD4 lymphopenia, TCR diversity and intensity of the T cell response. This also highlights the medical need for new therapies to restore T cell numbers and diversity and the urgency to find solutions for the clinical development of IL-7 allowing to regenerate thymic functions.
Blankenstein T, Coulie PG, Gilboa E, Jaffee EM. The determinants of tumour immunogenicity. Nat Rev Cancer. 2012;12:307–13.
Dunn GP, Old LJ, Schreiber RD. The immunobiology of cancer immunosurveillance and immunoediting. Immunity. 2004;21:137–48.
Penn I. Depressed immunity and the development of cancer. Cancer Detect Prev. 1994;18:241–52.
Fridman WH, Pages F, Sautes-Fridman C, Galon J. The immune contexture in human tumours: impact on clinical outcome. Nat Rev Cancer. 2012;12:298–306.
Apetoh L, Vegran F, Ladoire S, Ghiringhelli F. Restoration of antitumor immunity through selective inhibition of myeloid derived suppressor cells by anticancer therapies. Curr Mol Med. 2011;11:365–72.
Ruffell B, Affara NI, Coussens LM. Differential macrophage programming in the tumor microenvironment. Trends Immunol. 2012;33:119–26.
Ménétrier-Caux C, Curiel T, Faget J, Manuel M, Caux C, Zou W. Targeting regulatory T cells. Target Oncol. 2012;7:15–28.
Curiel TJ, Coukos G, Zou L, Alvarez X, Cheng P, Mottram P, et al. Specific recruitment of regulatory T cells in ovarian carcinoma fosters immune privilege and predicts reduced survival. Nat Med. 2004;10:942–9.
Faget J, Biota C, Bachelot T, Gobert M, Treilleux I, Goutagny N, et al. Early detection of tumor cells by innate immune cells leads to T(reg) recruitment through CCL22 production by tumor cells. Cancer Res. 2011;71:6143–52.
Yang P, Li QJ, Feng Y, Zhang Y, Markowitz GJ, Ning S, et al. TGF-beta-miR-34a-CCL22 signaling-induced Treg cell recruitment promotes venous metastases of HBV-positive hepatocellular carcinoma. Cancer Cell. 2012;22:291–303.
Gobert M, Treilleux I, Bendriss-Vermare N, Bachelot T, Goddard-Leon S, Arfi V, et al. Regulatory T cells recruited through CCL22/CCR4 are selectively activated in lymphoid infiltrates surrounding primary breast tumors and lead to an adverse clinical outcome. Cancer Res. 2009;69:2000–9.
Kalathil S, Lugade AA, Miller A, Iyer R, Thanavala Y. Higher frequencies of GARP(+)CTLA-4(+)Foxp3(+) T regulatory cells and myeloid-derived suppressor cells in hepatocellular carcinoma patients are associated with impaired T-cell functionality. Cancer Res. 2013;73:2435–44.
Le KS, Thibult ML, Just-Landi S, Pastor S, Gondois-Rey F, Granjeaud S, et al. Follicular B Lymphomas Generate Regulatory T Cells via the ICOS/ICOSL Pathway and Are Susceptible to Treatment by Anti-ICOS/ICOSL Therapy. Cancer Res. 2016;76:4648–60.
Conrad C, Gregorio J, Wang YH, Ito T, Meller S, Hanabuchi S, et al. Plasmacytoid Dendritic Cells Promote Immunosuppression in Ovarian Cancer via ICOS Costimulation of Foxp3+ T-Regulatory Cells. Cancer Res. 2012;72:5240–9.
Faget J, Bendriss-Vermare N, Gobert M, Durand I, Olive D, Biota C, et al. ICOS-ligand expression on plasmacytoid dendritic cells supports breast cancer progression by promoting the accumulation of immunosuppressive CD4+ T cells. Cancer Res. 2012;72:6130–41.
Labidi-Galy SI, Sisirak V, Meeus P, Gobert M, Treilleux I, Bajard A, et al. Quantitative and functional alterations of plasmacytoid dendritic cells contribute to immune tolerance in ovarian cancer. Cancer Res. 2011;71:5423–34.
Sisirak V, Faget J, Gobert M, Goutagny N, Vey N, Treilleux I, et al. Impaired IFN-alpha Production by Plasmacytoid Dendritic Cells Favors Regulatory T-cell Expansion That May Contribute to Breast Cancer Progression. Cancer Res. 2012;72:5188–97.
Bone G, Lauder I. Cellular immunity, peripheral blood lymphocyte count and pathological staging of tumours in the gastrointestinal tract. Br J Cancer. 1974;30:215–21.
Borg C, Ray-Coquard I, Philip I, Clapisson G, Bendriss-Vermare N, Menetrier-Caux C, et al. CD4 lymphopenia as a risk factor for febrile neutropenia and early death after cytotoxic chemotherapy in adult patients with cancer. Cancer. 2004;101:2675–80.
Peron J, Cropet C, Tredan O, Bachelot T, Ray-Coquard I, Clapisson G, et al. CD4 lymphopenia to identify end-of-life metastatic cancer patients. Eur J Cancer. 2013;49:1080–9.
Tredan O, Manuel M, Clapisson G, Bachelot T, Chabaud S, Bardin-dit-Courageot C, et al. Patients with metastatic breast cancer leading to CD4+ T cell lymphopaenia have poor outcome. Eur J Cancer. 2013;49:1673–82.
Ocana A, Nieto-Jimenez C, Pandiella A, Templeton AJ. Neutrophils in cancer: prognostic role and therapeutic strategies. Mol Cancer. 2017;16:137.
Bedimo RJ, McGinnis KA, Dunlap M, Rodriguez-Barradas MC, Justice AC. Incidence of non-AIDS-defining malignancies in HIV-infected versus noninfected patients in the HAART era: impact of immunosuppression. J Acquir Immune Defic Syndr. 2009;52:203–8.
Marin B, Thiebaut R, Bucher HC, Rondeau V, Costagliola D, Dorrucci M, et al. Non-AIDS-defining deaths and immunodeficiency in the era of combination antiretroviral therapy. AIDS. 2009;23:1743–53.
Smith C, Sabin CA, Lundgren JD, Thiebaut R, Weber R, Law M, et al. Factors associated with specific causes of death amongst HIV-positive individuals in the D:A:D Study. AIDS. 2010;24:1537–48.
An Y, Gao S, Zhao WC, Qiu BA, Xia NX, Zhang PJ, et al. Transforming growth factor-beta and peripheral regulatory cells are negatively correlated with the overall survival of hepatocellular carcinoma. World J Gastroenterol. 2018;24:2733–40.
Feng P, Yan R, Dai X, Xie X, Wen H, Yang S. The alteration and clinical significance of Th1/Th2/Th17/Treg cells in patients with multiple myeloma. Inflammation. 2015;38:705–9.
Shen P, Wang A, He M, Wang Q, Zheng S. Increased circulating Lin(-/low) CD33(+) HLA-DR(-) myeloid-derived suppressor cells in hepatocellular carcinoma patients. Hepatol Res. 2014;44:639–50.
Jacquelot N, Roberti MP, Enot DP, Rusakiewicz S, Semeraro M, Jegou S, et al. Immunophenotyping of Stage III Melanoma Reveals Parameters Associated with Patient Prognosis. J Invest Dermatol. 2016;136:994–1001.
Jacquelot N, Roberti MP, Enot DP, Rusakiewicz S, Ternes N, Jegou S, et al. Predictors of responses to immune checkpoint blockade in advanced melanoma. Nat Commun. 2017;8:592.
Mamessier E, Sylvain A, Thibult ML, Houvenaeghel G, Jacquemier J, Castellano R, et al. Human breast cancer cells enhance self tolerance by promoting evasion from NK cell antitumor immunity. J Clin Invest. 2011;121:3609–22.
Rocca YS, Roberti MP, Arriaga JM, Amat M, Bruno L, Pampena MB, et al. Altered phenotype in peripheral blood and tumor-associated NK cells from colorectal cancer patients. Innate Immun. 2013;19:76–85.
MJ SJ, Maecker HT, Park JW, Esserman LJ. Immune dysfunction and micrometastases in women with breast cancer. Breast Cancer Res Treat. 2005;91:2163–71.
Verronese E, Delgado A, Valladeau-Guilemond J, Garin G, Guillemaut S, Tredan O, et al. Immune cell dysfunctions in breast cancer patients detected through whole blood multi-parametric flow cytometry assay. Oncoimmunology. 2016;5:e1100791.
Shiraki T, Takayama E, Magari H, Nakata T, Maekita T, Enomoto S, et al. Altered cytokine levels and increased CD4+CD57+ T cells in the peripheral blood of hepatitis C virus-related hepatocellular carcinoma patients. Oncol Rep. 2011;26:201–8.
Chittezhath M, Dhillon MK, Lim JY, Laoui D, Shalova IN, Teo YL, et al. Molecular profiling reveals a tumor-promoting phenotype of monocytes and macrophages in human cancer progression. Immunity. 2014;41:815–29.
Ménétrier-Caux C, Gobert M, Caux C. Differences in tumor regulatory T-cell localization and activation status impact patient outcome. Cancer Res. 2009;69:7895–8.
Ramos RN, Chin LS, Dos Santos AP, Bergami-Santos PC, Laginha F, Barbuto JA. Monocyte-derived dendritic cells from breast cancer patients are biased to induce CD4+CD25+Foxp3+ regulatory T cells. J Leukoc Biol. 2012;92:673–82.
Vesely MD, Kershaw MH, Schreiber RD, Smyth MJ. Natural innate and adaptive immunity to cancer. Annu Rev Immunol. 2011;29:235–71.
Carreno BM, Magrini V, Becker-Hapak M, Kaabinejadian S, Hundal J, Petti AA, et al. Cancer immunotherapy. A dendritic cell vaccine increases the breadth and diversity of melanoma neoantigen-specific T cells. Science. 2015;348(6236):803–8.
Gubin MM, Zhang X, Schuster H, Caron E, Ward JP, Noguchi T, et al. Checkpoint blockade cancer immunotherapy targets tumour-specific mutant antigens. Nature. 2014;515:577–81.
Newrzela S, Al-Ghaili N, Heinrich T, Petkova M, Hartmann S, Rengstl B, et al. T-cell receptor diversity prevents T-cell lymphoma development. Leukemia. 2012;26:2499–507.
Palermo B, Del BD, Sottini A, Serana F, Ghidini C, Gualtieri N, et al. Dacarbazine treatment before peptide vaccination enlarges T-cell repertoire diversity of melan-a-specific, tumor-reactive CTL in melanoma patients. Cancer Res. 2010;70:7084–92.
Levy Y, Lacabaratz C, Weiss L, Viard JP, Goujard C, Lelievre JD, et al. Enhanced T cell recovery in HIV-1-infected adults through IL-7 treatment. J Clin Invest. 2009;119:997–1007.
Perales MA, Goldberg JD, Yuan J, Koehne G, Lechner L, Papadopoulos EB, et al. Recombinant human interleukin-7 (CYT107) promotes T-cell recovery after allogeneic stem cell transplantation. Blood. 2012;120:4882–91.
Rosenberg SA, Sportes C, Ahmadzadeh M, Fry TJ, Ngo LT, Schwarz SL, et al. IL-7 administration to humans leads to expansion of CD8+ and CD4+ cells but a relative decrease of CD4+ T-regulatory cells. J Immunother. 2006;29:313–9.
Sereti I, Dunham RM, Spritzler J, Aga E, Proschan MA, Medvik K, et al. IL-7 administration drives T cell-cycle entry and expansion in HIV-1 infection. Blood. 2009;113:6304–14.
Sportes C, Babb RR, Krumlauf MC, Hakim FT, Steinberg SM, Chow CK, et al. Phase I study of recombinant human interleukin-7 administration in subjects with refractory malignancy. Clin Cancer Res. 2010;16:727–35.
Halapi E. Oligoclonal T cells in human cancer. Med Oncol. 1998;15:203–11.
Manuel M, Tredan O, Bachelot T, Clapisson G, Courtier A, Parmentier G, et al. Lymphopenia combined with low TCR diversity (divpenia) predicts poor overall survival in metastatic breast cancer patients. Oncoimmunology. 2012;1:432–40.
Grulich AE, van Leeuwen MT, Falster MO, Vajdic CM. Incidence of cancers in people with HIV/AIDS compared with immunosuppressed transplant recipients: a meta-analysis. Lancet. 2007;370:59–67.
Ettorre GM, Piselli P, Galatioto L, Rendina M, Nudo F, Sforza D, et al. De novo malignancies following liver transplantation: results from a multicentric study in central and southern Italy, 1990-2008. Transplant Proc. 2013;45:2729–32.
Birkeland SA, Storm HH, Lamm LU, Barlow L, Blohme I, Forsberg B, et al. Cancer risk after renal transplantation in the Nordic countries, 1964-1986. Int J Cancer. 1995;60:183–9.
Ismail F, Mahmoud A, Abdelhaleem H, Mamdoh A, Geneidy M, Kamal E. Primary Sjogren's syndrome and B-non-Hodgkin lymphoma: role of CD4+ T lymphocytopenia. Rheumatol Int. 2013;33:1021–5.
Kojima M, Sakurai S, Morita Y, Nakamura N, Sugihara S, Shimano S. EBV(+) B-cell lymphoproliferative disorder associated with subsequent development of Burkitt lymphoma in a patient with idiopathic CD4(+) T-lymphocytopenia. J Clin Exp Hematop. 2008;48:55–9.
Michel JL, Perrot JL, Mitanne D, Boucheron S, Fond L, Cambazard F. Metastatic epidermoid carcinoma in idiopathic CD4+ T lymphocytopenia syndrome. Ann Dermatol Venereol. 1996;123:478–82.
Shiels MS, Pfeiffer RM, Gail MH, Hall HI, Li J, Chaturvedi AK, et al. Cancer burden in the HIV-infected population in the United States. J Natl Cancer Inst. 2011;103:753–62.
Engels EA, Pfeiffer RM, Goedert JJ, Virgo P, McNeel TS, Scoppa SM, et al. Trends in cancer risk among people with AIDS in the United States 1980-2002. AIDS. 2006;20:1645–54.
Blay JY, Chauvin F, Le CA, Anglaret B, Bouhour D, Lasset C, et al. Early lymphopenia after cytotoxic chemotherapy as a risk factor for febrile neutropenia. J Clin Oncol. 1996;14:636–43.
Blay JY, Le CA, Mermet C, Maugard C, Ravaud A, Chevreau C, et al. A risk model for thrombocytopenia requiring platelet transfusion after cytotoxic chemotherapy. Blood. 1998;92:405–10.
Marec-Berard P, Blay JY, Schell M, Buclon M, Demaret C, Ray-Coquard I. Risk model predictive of severe anemia requiring RBC transfusion after chemotherapy in pediatric solid tumor patients. J Clin Oncol. 2003;21:4235–8.
Ray-Coquard I, Le CA, Rubio MT, Mermet J, Maugard C, Ravaud A, et al. Risk model for severe anemia requiring red blood cell transfusion after cytotoxic conventional chemotherapy regimens. The Elypse 1 Study Group. J Clin Oncol. 1999;17:2840–6.
Ray-Coquard I, Ghesquiere H, Bachelot T, Borg C, Biron P, Sebban C, et al. Identification of patients at risk for early death after conventional chemotherapy in solid tumours and lymphomas. Br J Cancer. 2001;85:816–22.
Ray-Coquard I, Borg C, Bachelot T, Sebban C, Philip I, Clapisson G, et al. Baseline and early lymphopenia predict for the risk of febrile neutropenia after chemotherapy. Br J Cancer. 2003;88:181–6.
Saroha S, Uzzo RG, Plimack ER, Ruth K, Al-Saleem T. Lymphopenia is an independent predictor of inferior outcome in clear cell renal carcinoma. J Urol. 2013;189:454–61.
Ceze N, Thibault G, Goujon G, Viguier J, Watier H, Dorval E, et al. Pre-treatment lymphopenia as a prognostic biomarker in colorectal cancer patients receiving chemotherapy. Cancer Chemother Pharmacol. 2011;68:1305–13.
Choi CW, Sung HJ, Park KH, Yoon SY, Kim SJ, Oh SC, et al. Early lymphopenia as a risk factor for chemotherapy-induced febrile neutropenia. Am J Hematol. 2003;73:263–6.
Ray-Coquard I, Dussart S, Goillot C, Mayeur D, Debourdeau P, Ghesquieres H, et al. A risk model for severe anemia to select cancer patients for primary prophylaxis with epoetin alpha: a prospective randomized controlled trial of the ELYPSE study group. Ann Oncol. 2009;20:1105–12.
Shafer D, Smith MR, Borghaei H, Millenson MM, Li T, Litwin S, et al. Low NK cell counts in peripheral blood are associated with inferior overall survival in patients with follicular lymphoma. Leuk Res. 2013;37:1213–5.
Siddiqui M, Ristow K, Markovic SN, Witzig TE, Habermann TM, Colgan JP, et al. Absolute lymphocyte count predicts overall survival in follicular lymphomas. Br J Haematol. 2006;134:596–601.
Castillo JJ, Morales D, Quinones P, Cotrina E, Desposorio C, Beltran B. Lymphopenia as a prognostic factor in patients with peripheral T-cell lymphoma, unspecified. Leuk Lymphoma. 2010;51:1822–8.
Kim YR, Kim JS, Kim SJ, Jung HA, Kim SJ, Kim WS, et al. Lymphopenia is an important prognostic factor in peripheral T-cell lymphoma (NOS) treated with anthracycline-containing chemotherapy. J Hematol Oncol. 2011;4:34.
Ray-Coquard I, Cropet C, Van GM, Sebban C, Le CA, Judson I, et al. Lymphopenia as a prognostic factor for overall survival in advanced carcinomas, sarcomas, and lymphomas. Cancer Res. 2009;69:5383–91.
de Martino M, Pantuck AJ, Hofbauer S, Waldert M, Shariat SF, Belldegrun AS, et al. Prognostic impact of preoperative neutrophil-to-lymphocyte ratio in localized nonclear cell renal cell carcinoma. J Urol. 2013;190:1999–2004.
De Angulo G, Hernandez M, Morales-Arias J, Herzog CE, Anderson P, Wolff J, et al. Early lymphocyte recovery as a prognostic indicator for high-risk Ewing sarcoma. J Pediatr Hematol Oncol. 2007;29:48–52.
Venkatesulu BP, Mallick S, Lin SH, Krishnan S. A systematic review of the influence of radiation-induced lymphopenia on survival outcomes in solid tumors. Crit Rev Oncol Hematol. 2018;123:42–51.
Dufresne A, Bertucci F, Penel N, Le CA, Bui B, Tubiana-Hulin M, et al. Identification of biological factors predictive of response to imatinib mesylate in aggressive fibromatosis. Br J Cancer. 2010;103:482–5.
Fogar P, Basso D, Fadi E, Greco E, Pantano G, Padoan A, et al. Pancreatic cancer alters human CD4+ T lymphocyte function: a piece in the immune evasion puzzle. Pancreas. 2011;40:1131–7.
Cox MC, Nofroni I, Ruco L, Amodeo R, Ferrari A, La VG, et al. Low absolute lymphocyte count is a poor prognostic factor in diffuse-large-B-cell-lymphoma. Leuk Lymphoma. 2008;49:1745–51.
Oki Y, Yamamoto K, Kato H, Kuwatsuka Y, Taji H, Kagami Y, et al. Low absolute lymphocyte count is a poor prognostic marker in patients with diffuse large B-cell lymphoma and suggests patients’ survival benefit from rituximab. Eur J Haematol. 2008;81:448–53.
Hasenclever D, Diehl V. A prognostic score for advanced Hodgkin's disease. International Prognostic Factors Project on Advanced Hodgkin's Disease. N Engl J Med. 1998;339:1506–14.
Porrata LF, Ristow K, Colgan JP, Habermann TM, Witzig TE, Inwards DJ, et al. Peripheral blood lymphocyte/monocyte ratio at diagnosis and survival in classical Hodgkin's lymphoma. Haematologica. 2012;97:262–9.
Nagai S, Abouljoud MS, Kazimi M, Brown KA, Moonka D, Yoshida A. Peritransplant Lymphopenia Is a Novel Prognostic Factor in Recurrence of Hepatocellular Carcinoma After Liver Transplantation. Transplantation. 2014;59:35–45.
Shi LZ, Fu T, Guan B, Chen J, Blando JM, Allison JP, et al. Interdependent IL-7 and IFN-gamma signalling in T-cell controls tumour eradication by combined alpha-CTLA-4+alpha-PD-1 therapy. Nat Commun. 2016;7:12335.
Templeton AJ, McNamara MG, Seruga B, Vera-Badillo FE, Aneja P, Ocana A, et al. Prognostic role of neutrophil-to-lymphocyte ratio in solid tumors: a systematic review and meta-analysis. J Natl Cancer Inst. 2014;106:dju124.
Keane C, Tobin J, Talaulikar D, Green M, Crooks P, Jain S, et al. A high LDH to absolute lymphocyte count ratio in patients with DLBCL predicts for a poor intratumoral immune response and inferior survival. Oncotarget. 2018;9:23620–7.
Lee L, Fei L, Pope J, Wagner LM. Early Lymphocyte Recovery and Outcome in Osteosarcoma. J Pediatr Hematol Oncol. 2017;39:179–83.
Gergely L, Vancsa A, Miltenyi Z, Simon Z, Barath S, Illes A. Pretreatment T lymphocyte numbers are contributing to the prognostic significance of absolute lymphocyte numbers in B-cell non-Hodgkins lymphomas. Pathol Oncol Res. 2011;17:249–55.
De Giorgi U, Mego M, Scarpi E, Giuliano M, Giordano A, Reuben JM, et al. Relationship between lymphocytopenia and circulating tumor cells as prognostic factors for overall survival in metastatic breast cancer. Clin Breast Cancer. 2012;12:264–9.
Talaulikar D, Choudhury A, Shadbolt B, Brown M. Lymphocytopenia as a prognostic marker for diffuse large B cell lymphomas. Leuk Lymphoma. 2008;49:959–64.
Aoki T, Nishiyama T, Imahashi N, Kitamura K. Lymphopenia following the completion of first-line therapy predicts early relapse in patients with diffuse large B cell lymphoma. Ann Hematol. 2012;91:375–82.
Ege H, Gertz MA, Markovic SN, Lacy MQ, Dispenzieri A, Hayman SR, et al. Prediction of survival using absolute lymphocyte count for newly diagnosed patients with multiple myeloma: a retrospective study. Br J Haematol. 2008;141:792–8.
Mitrovic Z, Perry AM, Suzumiya J, Armitage JO, Au WY, Coiffier B, et al. The prognostic significance of lymphopenia in peripheral T-cell and natural killer/T-cell lymphomas: a study of 826 cases from the International Peripheral T-cell Lymphoma Project. Am J Hematol. 2012;87:790–4.
Plonquet A, Haioun C, Jais JP, Debard AL, Salles G, Bene MC, et al. Peripheral blood natural killer cell count is associated with clinical outcome in patients with aaIPI 2-3 diffuse large B-cell lymphoma. Ann Oncol. 2007;18:1209–15.
Rodriguez-Ruiz ME, Vanpouille-Box C, Melero I, Formenti SC, Demaria S. Immunological Mechanisms Responsible for Radiation-Induced Abscopal Effect. Trends Immunol. 2018;39:644–55.
Tang C, Liao Z, Gomez D, Levy L, Zhuang Y, Gebremichael RA, et al. Lymphopenia association with gross tumor volume and lung V5 and its effects on non-small cell lung cancer patient outcomes. Int J Radiat Oncol Biol Phys. 2014;89:1084–91.
Shiraishi Y, Fang P, Xu C, Song J, Krishnan S, Koay EJ, et al. Severe lymphopenia during neoadjuvant chemoradiation for esophageal cancer: A propensity matched analysis of the relative risk of proton versus photon-based radiation therapy. Radiother Oncol. 2018;128:154–60.
Yuan C, Wang Q. Comparative analysis of the effect of different radiotherapy regimes on lymphocyte and its subpopulations in breast cancer patients. Clin Transl Oncol. 2018;20:1219–25.
Jensen GL, Blanchard P, Gunn GB, Garden AS, David FC, Sturgis EM, et al. Prognostic impact of leukocyte counts before and during radiotherapy for oropharyngeal cancer. Clin Transl Radiat Oncol. 2017;7:28–35.
Gamberale R, Galmarini CM, Fernandez-Calotti P, Jordheim L, Sanchez-Avalos J, Dumontet C, et al. In vitro susceptibility of CD4+ and CD8+ T cell subsets to fludarabine. Biochem Pharmacol. 2003;66:2185–91.
Wijermans PW, Gerrits WB, Haak HL. Severe immunodeficiency in patients treated with fludarabine monophosphate. Eur J Haematol. 1993;50:292–6.
Ghiringhelli F, Menard C, Puig PE, Ladoire S, Roux S, Martin F, et al. Metronomic cyclophosphamide regimen selectively depletes CD4+CD25+ regulatory T cells and restores T and NK effector functions in end stage cancer patients. Cancer Immunol Immunother. 2007;56:641–8.
Ray-Coquard I, Favier L, Weber B, Roemer-Becuwe C, Bougnoux P, Fabbro M, et al. Everolimus as second- or third-line treatment of advanced endometrial cancer: ENDORAD, a phase II trial of GINECO. Br J Cancer. 2013;108:1771–7.
Novello S, Camps C, Grossi F, Mazieres J, Abrey L, Vernejoux JM, et al. Phase II study of sunitinib in patients with non-small cell lung cancer and irradiated brain metastases. J Thorac Oncol. 2011;6:1260–6.
Schilling B, Sondermann W, Zhao F, Griewank KG, Livingstone E, Sucker A, et al. Differential influence of vemurafenib and dabrafenib on patients’ lymphocytes despite similar clinical efficacy in melanoma. Ann Oncol. 2014;25:747–53.
Hong DS, Vence L, Falchook G, Radvanyi LG, Liu C, Goodman V, et al. BRAF(V600) inhibitor GSK2118436 targeted inhibition of mutant BRAF in cancer patients does not impair overall immune competency. Clin Cancer Res. 2012;18:2326–35.
Wilmott JS, Long GV, Howle JR, Haydu LE, Sharma RN, Thompson JF, et al. Selective BRAF inhibitors induce marked T-cell infiltration into human metastatic melanoma. Clin Cancer Res. 2012;18:1386–94.
Ohmachi K, Niitsu N, Uchida T, Kim SJ, Ando K, Takahashi N, et al. Multicenter phase II study of bendamustine plus rituximab in patients with relapsed or refractory diffuse large B-cell lymphoma. J Clin Oncol. 2013;31:2103–9.
Mackall CL, Fleisher TA, Brown MR, Magrath IT, Shad AT, Horowitz ME, et al. Lymphocyte depletion during treatment with intensive chemotherapy for cancer. Blood. 1994;84:2221–8.
Mackall CL, Fleisher TA, Brown MR, Andrich MP, Chen CC, Feuerstein IM, et al. Distinctions between CD8+ and CD4+ T-cell regenerative pathways result in prolonged T-cell subset imbalance after intensive chemotherapy. Blood. 1997;89:3700–7.
Sfikakis PP, Gourgoulis GM, Moulopoulos LA, Kouvatseas G, Theofilopoulos AN, Dimopoulos MA. Age-related thymic activity in adults following chemotherapy-induced lymphopenia. Eur J Clin Invest. 2005;35:380–7.
Zhang B, Sun T, Xue L, Han X, Zhang B, Lu N, et al. Functional polymorphisms in FAS and FASL contribute to increased apoptosis of tumor infiltration lymphocytes and risk of breast cancer. Carcinogenesis. 2007;28:1067–73.
Dworacki G, Meidenbauer N, Kuss I, Hoffmann TK, Gooding W, Lotze M, et al. Decreased zeta chain expression and apoptosis in CD3+ peripheral blood T lymphocytes of patients with melanoma. Clin Cancer Res. 2001;7:947s–57s.
Chevolet I, Speeckaert R, Schreuer M, Neyns B, Krysko O, Bachert C, et al. Characterization of the in vivo immune network of IDO, tryptophan metabolism, PD-L1, and CTLA-4 in circulating immune cells in melanoma. Oncoimmunology. 2015;4:e982382.
Agrawal S, Marquet J, Delfau-Larue MH, Copie-Bergman C, Jouault H, Reyes F, et al. CD3 hyporesponsiveness and in vitro apoptosis are features of T cells from both malignant and nonmalignant secondary lymphoid organs. J Clin Invest. 1998;102:1715–23.
Mahoney KM, Rennert PD, Freeman GJ. Combination cancer immunotherapy and new immunomodulatory targets. Nat Rev Drug Discov. 2015;14:561–84.
Keir ME, Liang SC, Guleria I, Latchman YE, Qipo A, Albacker LA, et al. Tissue expression of PD-L1 mediates peripheral T cell tolerance. J Exp Med. 2006;203:883–95.
Boyman O, Sprent J. The role of interleukin-2 during homeostasis and activation of the immune system. Nat Rev Immunol. 2012;12:180–90.
Abrams D, Levy Y, Losso MH, Babiker A, Collins G, Cooper DA, et al. Interleukin-2 therapy in patients with HIV infection. N Engl J Med. 2009;361:1548–59.
Weiss L, Letimier FA, Carriere M, Maiella S, Donkova-Petrini V, Targat B, et al. In vivo expansion of naive and activated CD4+CD25+FOXP3+ regulatory T cell populations in interleukin-2-treated HIV patients. Proc Natl Acad Sci U S A. 2010;107:10632–7.
Malek TR, Castro I. Interleukin-2 receptor signaling: at the interface between tolerance and immunity. Immunity. 2010;33:153–65.
Shevach EM. Mechanisms of foxp3+ T regulatory cell-mediated suppression. Immunity. 2009;30:636–45.
Fyfe G, Fisher RI, Rosenberg SA, Sznol M, Parkinson DR, Louie AC. Results of treatment of 255 patients with metastatic renal cell carcinoma who received high-dose recombinant interleukin-2 therapy. J Clin Oncol. 1995;13:688–96.
Atkins MB, Lotze MT, Dutcher JP, Fisher RI, Weiss G, Margolin K, et al. High-dose recombinant interleukin 2 therapy for patients with metastatic melanoma: analysis of 270 patients treated between 1985 and 1993. J Clin Oncol. 1999;17:2105–16.
Letsch A, Keilholz U, Schadendorf D, Nagorsen D, Schmittel A, Thiel E, et al. High frequencies of circulating melanoma-reactive CD8+ T cells in patients with advanced melanoma. Int J Cancer. 2000;87:659–64.
Ahmadzadeh M, Rosenberg SA. IL-2 administration increases CD4+ CD25(hi) Foxp3+ regulatory T cells in cancer patients. Blood. 2006;107:2409–14.
Cesana GC, DeRaffele G, Cohen S, Moroziewicz D, Mitcham J, Stoutenburg J, et al. Characterization of CD4+CD25+ regulatory T cells in patients treated with high-dose interleukin-2 for metastatic melanoma or renal cell carcinoma. J Clin Oncol. 2006;24:1169–77.
Carmenate T, Pacios A, Enamorado M, Moreno E, Garcia-Martinez K, Fuente D, et al. Human IL-2 mutein with higher antitumor efficacy than wild type IL-2. J Immunol. 2013;190:6230–8.
Heaton KM, Ju G, Grimm EA. Human interleukin 2 analogues that preferentially bind the intermediate-affinity interleukin 2 receptor lead to reduced secondary cytokine secretion: implications for the use of these interleukin 2 analogues in cancer immunotherapy. Cancer Res. 1993;53:2597–602.
Sim GC, Liu C, Wang E, Liu H, Creasy C, Dai Z, et al. IL2 Variant Circumvents ICOS+ Regulatory T-cell Expansion and Promotes NK Cell Activation. Cancer Immunol Res. 2016;4:983–94.
Waldmann TA. The biology of interleukin-2 and interleukin-15: implications for cancer therapy and vaccine design. Nat Rev Immunol. 2006;6:595–601.
Marks-Konczalik J, Dubois S, Losi JM, Sabzevari H, Yamada N, Feigenbaum L, et al. IL-2-induced activation-induced cell death is inhibited in IL-15 transgenic mice. Proc Natl Acad Sci U S A. 2000;97:11445–50.
Sanjabi S, Mosaheb MM, Flavell RA. Opposing effects of TGF-beta and IL-15 cytokines control the number of short-lived effector CD8+ T cells. Immunity. 2009;31:131–44.
Sneller MC, Kopp WC, Engelke KJ, Yovandich JL, Creekmore SP, Waldmann TA, et al. IL-15 administered by continuous infusion to rhesus macaques induces massive expansion of CD8+ T effector memory population in peripheral blood. Blood. 2011;118:6845–8.
Berger C, Berger M, Hackman RC, Gough M, Elliott C, Jensen MC, et al. Safety and immunologic effects of IL-15 administration in nonhuman primates. Blood. 2009;114:2417–26.
Conlon KC, Lugli E, Welles HC, Rosenberg SA, Fojo AT, Morris JC, et al. Redistribution, hyperproliferation, activation of natural killer cells and CD8 T cells, and cytokine production during first-in-human clinical trial of recombinant human interleukin-15 in patients with cancer. J Clin Oncol. 2015;33:74–82.
Waldmann TA. The shared and contrasting roles of IL2 and IL15 in the life and death of normal and neoplastic lymphocytes: implications for cancer therapy. Cancer Immunol Res. 2015;3:219–27.
Steel JC, Waldmann TA, Morris JC. Interleukin-15 biology and its therapeutic implications in cancer. Trends Pharmacol Sci. 2012;33:35–41.
Rhode PR, Egan JO, Xu W, Hong H, Webb GM, Chen X, et al. Comparison of the Superagonist Complex, ALT-803, to IL15 as Cancer Immunotherapeutics in Animal Models. Cancer Immunol Res. 2016;4:49–60.
Han KP, Zhu X, Liu B, Jeng E, Kong L, Yovandich JL, et al. IL-15:IL-15 receptor alpha superagonist complex: high-level co-expression in recombinant mammalian cells, purification and characterization. Cytokine. 2011;56:804–10.
Alpdogan O, van den Brink MR. IL-7 and IL-15: therapeutic cytokines for immunodeficiency. Trends Immunol. 2005;26:56–64.
Peschon JJ, Morrissey PJ, Grabstein KH, Ramsdell FJ, Maraskovsky E, Gliniak BC, et al. Early lymphocyte expansion is severely impaired in interleukin 7 receptor-deficient mice. J Exp Med. 1994;180:1955–60.
Puel A, Ziegler SF, Buckley RH, Leonard WJ. Defective IL7R expression in T(-)B(+)NK(+) severe combined immunodeficiency. Nat Genet. 1998;20:394–7.
Plum J, De SM, Leclercq G, Verhasselt B, Vandekerckhove B. Interleukin-7 is a critical growth factor in early human T-cell development. Blood. 1996;88:4239–45.
Fry TJ, Connick E, Falloon J, Lederman MM, Liewehr DJ, Spritzler J, et al. A potential role for interleukin-7 in T-cell homeostasis. Blood. 2001;97:2983–90.
Schluns KS, Kieper WC, Jameson SC, Lefrancois L. Interleukin-7 mediates the homeostasis of naive and memory CD8 T cells in vivo. Nat Immunol. 2000;1:426–32.
Morrissey PJ, Charrier K, Horovitz DA, Fletcher FA, Watson JD. Analysis of the intra-epithelial lymphocyte compartment in SCID mice that received co-isogenic CD4+ T cells. Evidence that mature post-thymic CD4+ T cells can be induced to express CD8 alpha in vivo. J Immunol. 1995;154:2678–86.
Alpdogan O, Schmaltz C, Muriglan SJ, Kappel BJ, Perales MA, Rotolo JA, et al. Administration of interleukin-7 after allogeneic bone marrow transplantation improves immune reconstitution without aggravating graft-versus-host disease. Blood. 2001;98:2256–65.
Storek J, Gillespy T III, Lu H, Joseph A, Dawson MA, Gough M, et al. Interleukin-7 improves CD4 T-cell reconstitution after autologous CD34 cell transplantation in monkeys. Blood. 2003;101:4209–18.
Parker R, Dutrieux J, Beq S, Lemercier B, Rozlan S, Fabre-Mersseman V, et al. Interleukin-7 treatment counteracts IFN-alpha therapy-induced lymphopenia and stimulates SIV-specific cytotoxic T lymphocyte responses in SIV-infected rhesus macaques. Blood. 2010;116:5589–99.
Beq S, Nugeyre MT, Ho Tsong FR, Gautier D, Legrand R, Schmitt N, et al. IL-7 induces immunological improvement in SIV-infected rhesus macaques under antiviral therapy. J Immunol. 2006;176:914–22.
Pellegrini M, Calzascia T, Elford AR, Shahinian A, Lin AE, Dissanayake D, et al. Adjuvant IL-7 antagonizes multiple cellular and molecular inhibitory networks to enhance immunotherapies. Nat Med. 2009;15:528–36.
Mackall CL, Fry TJ, Gress RE. Harnessing the biology of IL-7 for therapeutic application. Nat Rev Immunol. 2011;11:330–42.
Morre M, Beq S. Interleukin-7 and immune reconstitution in cancer patients: a new paradigm for dramatically increasing overall survival. Target Oncol. 2012;7:55–68.
Beq S, Rozlan S, Gautier D, Parker R, Mersseman V, Schilte C, et al. Injection of glycosylated recombinant simian IL-7 provokes rapid and massive T-cell homing in rhesus macaques. Blood. 2009;114:816–25.
Younas M, Hue S, Lacabaratz C, Guguin A, Wiedemann A, Surenaud M, et al. IL-7 modulates in vitro and in vivo human memory T regulatory cell functions through the CD39/ATP axis. J Immunol. 2013;191:3161–8.
Gagnon J, Chen XL, Forand-Boulerice M, Leblanc C, Raman C, Ramanathan S, et al. Increased antigen responsiveness of naive CD8 T cells exposed to IL-7 and IL-21 is associated with decreased CD5 expression. Immunol Cell Biol. 2010;88:451–60.
Melchionda F, Fry TJ, Milliron MJ, McKirdy MA, Tagaya Y, Mackall CL. Adjuvant IL-7 or IL-15 overcomes immunodominance and improves survival of the CD8+ memory cell pool. J Clin Invest. 2005;115:1177–87.
Sportes C, Hakim FT, Memon SA, Zhang H, Chua KS, Brown MR, et al. Administration of rhIL-7 in humans increases in vivo TCR repertoire diversity by preferential expansion of naive T cell subsets. J Exp Med. 2008;205:1701–14.
Tredan O, Menetrier-Caux C, Ray-Coquard I, Garin G, Cropet C, Verronese E, et al. ELYPSE-7: a randomized placebo-controlled phase IIa trial with CYT107 exploring the restoration of CD4+ lymphocyte count in lymphopenic metastatic breast cancer patients. Ann Oncol. 2015;26:1353–62.
Thiebaut R, Drylewicz J, Prague M, Lacabaratz C, Beq S, Jarne A, et al. Quantifying and predicting the effect of exogenous interleukin-7 on CD4+ T cells in HIV-1 infection. PLoS Comput Biol. 2014;10:e1003630.
Merchant MS, Bernstein D, Amoako M, Baird K, Fleisher TA, Morre M, et al. Adjuvant Immunotherapy to Improve Outcome in High-Risk Pediatric Sarcomas. Clin Cancer Res. 2016;22:3182–91.
Ribas A, Wolchok JD. Cancer immunotherapy using checkpoint blockade. Science. 2018;359:1350–5.
Zappasodi R, Merghoub T, Wolchok JD. Emerging Concepts for Immune Checkpoint Blockade-Based Combination Therapies. Cancer Cell. 2018;33:581–98.
Delyon J, Mateus C, Lefeuvre D, Lanoy E, Zitvogel L, Chaput N, et al. Experience in daily practice with ipilimumab for the treatment of patients with metastatic melanoma: an early increase in lymphocyte and eosinophil counts is associated with improved survival. Ann Oncol. 2013;24:1697–703.
Martens A, Wistuba-Hamprecht K, Yuan J, Postow MA, Wong P, Capone M, et al. Increases in Absolute Lymphocytes and Circulating CD4+ and CD8+ T Cells Are Associated with Positive Clinical Outcome of Melanoma Patients Treated with Ipilimumab. Clin Cancer Res. 2016;22:4848–58.
Nakamura Y, Kitano S, Takahashi A, Tsutsumida A, Namikawa K, Tanese K, et al. Nivolumab for advanced melanoma: pretreatment prognostic factors and early outcome markers during therapy. Oncotarget. 2016;7:77404–15.
Weide B, Martens A, Hassel JC, Berking C, Postow MA, Bisschop K, et al. Baseline Biomarkers for Outcome of Melanoma Patients Treated with Pembrolizumab. Clin Cancer Res. 2016;22:5487–96.
Ménard C, Ghiringhelli F, Roux S, Chaput N, Mateus C, Grohmann U, et al. Ctla-4 blockade confers lymphocyte resistance to regulatory T-cells in advanced melanoma: surrogate marker of efficacy of tremelimumab? Clin Cancer Res. 2008;14:5242–9.
Diehl A, Yarchoan M, Hopkins A, Jaffee E, Grossman SA. Relationships between lymphocyte counts and treatment-related toxicities and clinical responses in patients with solid tumors treated with PD-1 checkpoint inhibitors. Oncotarget. 2017;8:114268–80.
Ho WJ, Yarchoan M, Hopkins A, Mehra R, Grossman S, Kang H. Association between pretreatment lymphocyte count and response to PD1 inhibitors in head and neck squamous cell carcinomas. J Immunother Cancer. 2018;6:84.
Karantanos T, Moliterno AR. The roles of JAK2 in DNA damage and repair in the myeloproliferative neoplasms: Opportunities for targeted therapy. Blood Rev. 2018;32:426–32.
Simeone E, Gentilcore G, Giannarelli D, Grimaldi AM, Caraco C, Curvietto M, et al. Immunological and biological changes during ipilimumab treatment and their potential correlation with clinical response and survival in patients with advanced melanoma. Cancer Immunol Immunother. 2014;63:675–83.
Subrahmanyam PB, Dong Z, Gusenleitner D, Giobbie-Hurder A, Severgnini M, Zhou J, et al. Distinct predictive biomarker candidates for response to anti-CTLA-4 and anti-PD-1 immunotherapy in melanoma patients. J Immunother Cancer. 2018;6:18.
Kvistborg P, Philips D, Kelderman S, Hageman L, Ottensmeier C, Joseph-Pietras D, et al. Anti-CTLA-4 therapy broadens the melanoma-reactive CD8+ T cell response. Sci Transl Med. 2014;6:254ra128.
Wang W, Yu D, Sarnaik AA, Yu B, Hall M, Morelli D, et al. Biomarkers on melanoma patient T cells associated with ipilimumab treatment. J Transl Med. 2012;10:146–58.
Takeuchi Y, Tanemura A, Tada Y, Katayama I, Kumanogoh A, Nishikawa H. Clinical response to PD-1 blockade correlates with a sub-fraction of peripheral central memory CD4+ T cells in patients with malignant melanoma. Int Immunol. 2018;30:13–22.
Carthon BC, Wolchok JD, Yuan J, Kamat A, Ng Tang DS, Sun J, et al. Preoperative CTLA-4 blockade: tolerability and immune monitoring in the setting of a presurgical clinical trial. Clin Cancer Res. 2010;16:2861–71.
Di Giacomo AM, Calabro L, Danielli R, Fonsatti E, Bertocci E, Pesce I, et al. Long-term survival and immunological parameters in metastatic melanoma patients who responded to ipilimumab 10 mg/kg within an expanded access programme. Cancer Immunol Immunother. 2013;62:1021–8.
Liakou CI, Kamat A, Tang DN, Chen H, Sun J, Troncoso P, et al. CTLA-4 blockade increases IFNgamma-producing CD4+ICOShi cells to shift the ratio of effector to regulatory T cells in cancer patients. Proc Natl Acad Sci U S A. 2008;105:14987–92.
Ng TD, Shen Y, Sun J, Wen S, Wolchok JD, Yuan J, et al. Increased frequency of ICOS+ CD4 T cells as a pharmacodynamic biomarker for anti-CTLA-4 therapy. Cancer Immunol Res. 2013;1:229–34.
Snyder A, Nathanson T, Funt SA, Ahuja A, Buros NJ, Hellmann MD, et al. Contribution of systemic and somatic factors to clinical response and resistance to PD-L1 blockade in urothelial cancer: An exploratory multi-omic analysis. PLoS Med. 2017;14:e1002309.
Funt S, Charen AS, Yusko E, Vignali M, Benzeno S, Boyd ME. Correlation of peripheral and intratumoral T-cell receptor (TCR) clonality with clinical outcomes in patients with metastatic urothelial cancer (mUC) treated with atezolizumab. J.Clin.Oncol. 2016;34:abstract 3005.
Goldinger SM, Tsai KK, Tumeh P, Hamid O, Nosrati A, Loo K. Correlation between metastatic site and response to anti-Programmed Death-1 (PD-1) agents in melanoma. J Clin Oncol. 2016;34:abstract 9549.
Postow MA, Manuel M, Wong P, Yuan J, Dong Z, Liu C, et al. Peripheral T cell receptor diversity is associated with clinical outcomes following ipilimumab treatment in metastatic melanoma. J Immunother Cancer. 2015;3:23.
Robert L, Tsoi J, Wang X, Emerson R, Homet B, Chodon T, et al. CTLA4 blockade broadens the peripheral T-cell receptor repertoire. Clin Cancer Res. 2014;20:2424–32.
Cha E, Klinger M, Hou Y, Cummings C, Ribas A, Faham M, et al. Improved survival with T cell clonotype stability after anti-CTLA-4 treatment in cancer patients. Sci Transl Med. 2014;6:238ra70.
Sacdalan DB, Lucero JA, Sacdalan DL. Prognostic utility of baseline neutrophil-to-lymphocyte ratio in patients receiving immune checkpoint inhibitors: a review and meta-analysis. Onco Targets Ther. 2018;11:955–65.
Suh KJ, Kim SH, Kim YJ, Kim M, Keam B, Kim TM, et al. Post-treatment neutrophil-to-lymphocyte ratio at week 6 is prognostic in patients with advanced non-small cell lung cancers treated with anti-PD-1 antibody. Cancer Immunol Immunother. 2018;67:459–70.
Soyano AE, Dholaria B, Marin-Acevedo JA, Diehl N, Hodge D, Luo Y, et al. Peripheral blood biomarkers correlate with outcomes in advanced non-small cell lung Cancer patients treated with anti-PD-1 antibodies. J Immunother Cancer. 2018;6:129.
Maymani H, Hess K, Groisberg R, Hong DS, Naing A, Piha-Paul S, et al. Predicting outcomes in patients with advanced non-small cell lung cancer enrolled in early phase immunotherapy trials. Lung Cancer. 2018;120:137–41.
Gebhardt C, Sevko A, Jiang H, Lichtenberger R, Reith M, Tarnanidis K, et al. Myeloid Cells and Related Chronic Inflammatory Factors as Novel Predictive Markers in Melanoma Treatment with Ipilimumab. Clin Cancer Res. 2015;21:5453–9.
Weber J, Gibney G, Kudchadkar R, Yu B, Cheng P, Martinez AJ, et al. Phase I/II Study of Metastatic Melanoma Patients Treated with Nivolumab Who Had Progressed after Ipilimumab. Cancer Immunol Res. 2016;4:345–53.
Krieg C, Nowicka M, Guglietta S, Schindler S, Hartmann FJ, Weber LM, et al. High-dimensional single-cell analysis predicts response to anti-PD-1 immunotherapy. Nat Med. 2018;24:144–53.
Carretero R, Sektioglu IM, Garbi N, Salgado OC, Beckhove P, Hammerling GJ. Eosinophils orchestrate cancer rejection by normalizing tumor vessels and enhancing infiltration of CD8(+) T cells. Nat Immunol. 2015;16:609–17.
Balatoni T, Ladányi A, Fröhlich G, Czirbesz K, Kovacs P, Panczel G, et al. Pathol Oncol Res. 2018. https://doi.org/10.1007/s12253-018-0466-9.
Ferrucci PF, Gandini S, Cocorocchio E, Pala L, Baldini F, Mosconi M, et al. Baseline relative eosinophil count as a predictive biomarker for ipilimumab treatment in advanced melanoma. Oncotarget. 2017;8:79809–15.
Zhou J, Mahoney KM, Giobbie-Hurder A, Zhao F, Lee S, Liao X, et al. Soluble PD-L1 as a Biomarker in Malignant Melanoma Treated with Checkpoint Blockade. Cancer Immunol Res. 2017;5:480–92.
Holdenrieder S, Stieber P, Peterfi A, Nagel D, Steinle A, Salih HR. Soluble MICB in malignant diseases: analysis of diagnostic significance and correlation with soluble MICA. Cancer Immunol Immunother. 2006;55:1584–9.
Maccalli C, Giannarelli D, Chiarucci C, Cutaia O, Giacobini G, Hendrickx W, et al. Soluble NKG2D ligands are biomarkers associated with the clinical outcome to immune checkpoint blockade therapy of metastatic melanoma patients. Oncoimmunology. 2017;6:e1323618.
Hannani D, Vetizou M, Enot D, Rusakiewicz S, Chaput N, Klatzmann D, et al. Anticancer immunotherapy by CTLA-4 blockade: obligatory contribution of IL-2 receptors and negative prognostic impact of soluble CD25. Cell Res. 2015;25:208–24.
Huang AC, Postow MA, Orlowski RJ, Mick R, Bengsch B, Manne S, et al. T-cell invigoration to tumour burden ratio associated with anti-PD-1 response. Nature. 2017;545:60–5.
Manjarrez-Orduno N, Menard LC, Kansal S, Fischer P, Kakrecha B, Jiang C, et al. Circulating T Cell Subpopulations Correlate With Immune Responses at the Tumor Site and Clinical Response to PD1 Inhibition in Non-Small Cell Lung Cancer. Front Immunol. 2018;9:1613.
Heylmann D, Bauer M, Becker H, van GS BN, Steinbrink K, et al. Human CD4+CD25+ regulatory T cells are sensitive to low dose cyclophosphamide: implications for the immune response. PLoS One. 2013;8(12):e83384.
Deng L, Liang H, Burnette B, Weicheslbaum RR, Fu YX. Radiation and anti-PD-L1 antibody combinatorial therapy induces T cell-mediated depletion of myeloid-derived suppressor cells and tumor regression. Oncoimmunology. 2014;3:e28499.
Sharabi AB, Tran PT, Lim M, Drake CG, TL DW. Stereotactic radiation therapy combined with immunotherapy: augmenting the role of radiation in local and systemic treatment. Oncol. 2015;29:331–40.
Twyman-Saint VC, Rech AJ, Maity A, Rengan R, Pauken KE, Stelekati E, et al. Radiation and dual checkpoint blockade activate non-redundant immune mechanisms in cancer. Nature. 2015;520:373–7.
Zeng J, See AP, Phallen J, Jackson CM, Belcaid Z, Ruzevick J, et al. Anti-PD-1 blockade and stereotactic radiation produce long-term survival in mice with intracranial gliomas. Int J Radiat Oncol Biol Phys. 2013;86:343–9.
Sindoni A, Minutoli F, Ascenti G, Pergolizzi S. Combination of immune checkpoint inhibitors and radiotherapy: Review of the literature. Crit Rev Oncol Hematol. 2017;113:63–70.
Gattinoni L, Finkelstein SE, Klebanoff CA, Antony PA, Palmer DC, Spiess PJ, et al. Removal of homeostatic cytokine sinks by lymphodepletion enhances the efficacy of adoptively transferred tumor-specific CD8+ T cells. J Exp Med. 2005;202:907–12.
Mullinax JE, Hall M, Prabhakaran S, Weber J, Khushalani N, Eroglu Z, et al. Combination of Ipilimumab and Adoptive Cell Therapy with Tumor-Infiltrating Lymphocytes for Patients with Metastatic Melanoma. Front Oncol. 2018;8:44.
Kinter AL, Godbout EJ, McNally JP, Sereti I, Roby GA, O'Shea MA, et al. The common gamma-chain cytokines IL-2, IL-7, IL-15, and IL-21 induce the expression of programmed death-1 and its ligands. J Immunol. 2008;181:6738–46.
Alva A, Daniels GA, Wong MK, Kaufman HL, Morse MA, McDermott DF, et al. Contemporary experience with high-dose interleukin-2 therapy and impact on survival in patients with metastatic melanoma and metastatic renal cell carcinoma. Cancer Immunol Immunother. 2016;65:1533–44.
Klein C, Waldhauer I, Nicolini VG, Freimoser-Grundschober A, Nayak T, Vugts DJ, et al. Cergutuzumab amunaleukin (CEA-IL2v), a CEA-targeted IL-2 variant-based immunocytokine for combination cancer immunotherapy: Overcoming limitations of aldesleukin and conventional IL-2-based immunocytokines. Oncoimmunology. 2017;6:e1277306.
We would also like to thank Pr. C Dumontet for critical reading of the manuscript.
Breast Cancer Research Foundation (BCRF)(JYB), SIRIC project (LYRICAN, INCa-DGOS-Inserm_12563) (JYB), INCa (Translational research grants 2011-052 and 2013-208)(CC), FUI AAP-10 DIVRESCUE (OSEO F1105032Z and Région Rhône-Alpes N° 1101030301) (CMC), LABEX DEVweCAN (ANR-10-LABX-0061) of the University of Lyon (CC).
Availability of data and materials
Ethics approval and consent to participate
Consent for publication
The authors declare that they have no competing interests.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
About this article
Cite this article
Ménétrier-Caux, C., Ray-Coquard, I., Blay, JY. et al. Lymphopenia in Cancer Patients and its Effects on Response to Immunotherapy: an opportunity for combination with Cytokines?. j. immunotherapy cancer 7, 85 (2019). https://doi.org/10.1186/s40425-019-0549-5
- solid tumors
- TCR diversity
- anti-cancer immunotherapy