Early lymphocyte recovery is a predictive factor for prolonged survival after autologous hematopoietic stem cell transplantation for acute myelogenous leukemia

Effect of changes in lymphocyte subsets at diagnosis in acute myeloid leukemia on prognosis: association with complete remission rates and relapse free survivals

We prospectively investigated whether the characteristics of lymphocyte subsets at diagnosis in acute myeloid leukemia (AML) patients are different from healthy controls and affect treatment outcomes. A total of 91 AML patients classified into 3 genetic risk subgroups (favorable/intermediate/poor) according to 2022 NCCN guidelines were enrolled. We measured lymphocyte subsets by flow cytometry with peripheral blood samples at diagnosis and compared results with healthy controls. Influences of lymphocyte subsets on complete remission (CR) rates and survivals were also evaluated. AML patients had significantly lower numbers and proportions of CD56dimCD16+ natural killer (NK) cells, central memory T cells, and regulatory T cells than healthy controls. Higher proportion of helper/inducer T cells, CD4+CD31+ naïve T cells, and decreased proportion of NK cells significantly increased CR rates in 65 non-promyelocytic leukemia patients (P = 0.034, 0.027, and 0.019, respectively), and it was also significant in multivariable analysis with age/risk adjusted (P = 0.014, 0.016, and 0.045, respectively). NK cells < 4.8% of lymphocytes demonstrated significantly shorter relapse free survivals (RFS) in both univariate and multivariate analyses with risk adjusted (P = 0.006 and 0.037, respectively). AML patients showed significant lower numbers of CD56dimCD16+ NK cells, central memory T cells, and regulatory T cells than healthy controls at diagnosis. Higher proportion of helper/inducer T cells and CD4+CD31+ naïve T cells and decreased proportion of NK cells at diagnosis were independent factor of increasing probability of CR, and proportion of NK cells < 4.8% at diagnosis had adverse impact in RFS.

Prognostic Role of Cell Blood Count in Chronic Myeloid Neoplasm and Acute Myeloid Leukemia and Its Possible Implications in Hematopoietic Stem Cell Transplantation

Numerous prognostic indexes have been developed in hematological diseases based on patient characteristics and genetic or molecular assessment. However, less attention was paid to more accessible parameters, such as neutrophils, lymphocytes, monocytes, and platelet counts. Although many studies have defined the role of neutrophil-to-lymphocyte or platelet-to-lymphocyte in lymphoid malignancies, few applications exist for myeloid neoplasm or hematopoietic stem cell transplantation procedures. In this review, we synthesized literature data on the prognostic value of count blood cells in myeloid malignancies and hematopoietic stem cell transplantation in the context of classical prognostic factors and clinical outcomes.

The Impact of Infused Autograft Absolute Numbers of Immune Effector Cells on Survival Post-Autologous Stem Cell Transplantation

Autologous stem cell transplantation treatment has been viewed as a therapeutic modality to enable the infusion of higher doses of chemotherapy to eradicate tumor cells. Nevertheless, recent reports have shown that, in addition to stem cells, infusion of autograft immune effector cells produces an autologous graft-versus-tumor effect, similar to the graft-versus-tumor effect observed in allogeneic-stem cell transplantation, but without the clinical complications of graft-versus-host disease. In this review, I assess the impact on clinical outcomes following infusions of autograft-antigen presenting cells, autograft innate and adaptive immune effector cells, and autograft immunosuppressive cells during autologous stem cell transplantation. This article is intended to provide a platform to change the current paradigmatic view of autologous stem cell transplantation, from a high-dose chemotherapy-based treatment to an adoptive immunotherapeutic intervention.

Early Adaptive Natural Killer Cell Expansion Is Associated with Decreased Relapse After Autologous Transplantation for Multiple Myeloma

Adaptive natural killer (NK) cells are long-lived and exhibit properties of immunologic memory against cytomegalovirus (CMV). We previously reported that expansion of adaptive NK cells after CMV reactivation in recipients of allogeneic hematopoietic cell transplantation (HCT) was associated with a lower rate of relapse of acute myelogenous leukemia. In the present study, we examined the impact of adaptive NK cell expansion in a cohort of 110 individuals who underwent autologous HCT (AHCT) for a lymphoid malignancy (lymphoma or multiple myeloma [MM]). In this cohort, higher absolute numbers of adaptive NK cells (>1.58/μL) at day 28 post-AHCT were associated with significantly decreased risk of relapse in patients with MM. No significant association was seen in patients with lymphoma. Further stratification of MM patients by CMV serostatus found a strong protective effect of adaptive NK cells only in CMV-seropositive individuals. These findings suggest that strategies to increase adaptive NK cells after AHCT may be a therapeutic option in patients with MM.

Human NK Cells in Autologous Hematopoietic Stem Cell Transplantation for Cancer Treatment

Simple Summary

Natural killer (NK) cells are key elements of the innate immune system that have the ability to kill transformed (tumor and virus-infected) cells without prior sensitization. Hematopoietic stem cell transplantation (HSCT) is a medical procedure used in the treatment of a variety of cancers. The early reconstitution of NK cells after HSCT and their functions support the therapeutic potential of these cells in allogenic HSCT. However, the role of NK cells in autologous HSCT is less clear. In this review, we have summarized general aspects of NK cell biology. In addition, we have also reviewed factors that affect autologous HSCT outcome, with particular attention to the role played by NK cells.

Abstract

Natural killer (NK) cells are phenotypically and functionally diverse lymphocytes with the ability to recognize and kill malignant cells without prior sensitization, and therefore, they have a relevant role in tumor immunosurveillance. NK cells constitute the main lymphocyte subset in peripheral blood in the first week after hematopoietic stem cell transplantation (HSCT). Although the role that NK cells play in allogenic HSCT settings has been documented for years, their significance and beneficial effects associated with the outcome after autologous HSCT are less recognized. In this review, we have summarized fundamental aspects of NK cell biology, such as, NK cell subset diversity, their effector functions, and differentiation. Moreover, we have reviewed the factors that affect autologous HSCT outcome, with particular attention to the role played by NK cells and their receptor repertoire in this regard.

Immunosuppression and Immunotargeted Therapy in Acute Myeloid Leukemia - The Potential Use of Checkpoint Inhibitors in Combination with Other Treatments

INTRODUCTION

Immunotherapy by using checkpoint inhibitors is now tried in the treatment of several malignancies, including Acute Myeloid Leukemia (AML). The treatment is tried both as monotherapy and as a part of combined therapy.

METHODS

Relevant publications were identified through literature searches in the PubMed database. We searched for (i) original articles describing the results from clinical studies of checkpoint inhibition; (ii) published articles describing the immunocompromised status of AML patients; and (iii) published studies of antileukemic immune reactivity and immunotherapy in AML.

RESULTS

Studies of monotherapy suggest that checkpoint inhibition has a modest antileukemic effect and complete hematological remissions are uncommon, whereas combination with conventional chemotherapy increases the antileukemic efficiency with acceptable toxicity. The experience with a combination of different checkpoint inhibitors is limited. Thalidomide derivatives are referred to as immunomodulatory drugs and seem to reverse leukemia-induced immunosuppression, but in addition, they have direct inhibitory effects on the AML cells. The combination of checkpoint targeting and thalidomide derivatives thus represents a strategy for dual immunotargeting together with a direct antileukemic effect.

CONCLUSION

Checkpoint inhibitors are now tried in AML. Experimental studies suggest that these inhibitors should be combined with immunomodulatory agents (i.e. thalidomide derivatives) and/or new targeted or conventional antileukemic treatment. Such combinations would allow dual immunotargeting (checkpoint inhibitor, immunomodulatory agents) together with a double/triple direct targeting of the leukemic cells.

Absolute Monocyte Count is Superior than Absolute Lymphocyte Count at Day 28 as an Independent Prognostic Factor in Acute Myeloid Leukemia

Leukemia is one of leading causes of death despite the significant improvement of survival. This study aimed at assessing the impact of absolute monocytic count (AMC), and absolute lymphocytic count (ALC) recovery on overall survival (OS) and leukemia free survival (LFS) in AML. 83 de novo AML cases were enrolled in this study. The hemogram parameters including differential leukocyte counts were determined and collected sequentially at days 1, 14, 21 and 28. There was no significant difference regarding AMC or ALC at any time points in relation to the cytogenetics prognostic groups. High AMC ≥ 0.8 × 10⁹/L at day 28 was associated with shorter OS and LFS, P value 0.012 and 0.003 respectively. On multivariate models, high AMC was shown as an independent prognostic factor associated with poor OS and LFS (HR 3, 95% CI 1.1-8.1 and P value 0.02) and (HR 5, 95% CI 1.5-17.4 and P value 0.01) respectively. High ALC-D28 (≥ 0.35 × 10⁹/L) was associated with prolonged OS and LFS survival, P value 0.032 and 0.016 respectively. However, it failed to prove the same significance using multivariate analysis. It was concluded that low AMC is an emerging independent predictor of better outcome in AML.

A comparison of the effect of xinruibai versus filgrastim on hematopoietic reconstruction after allogeneic hematopoietic stem cell transplantation

Background

To compare the effect of xinruibai (Pegfilgrastim) and filgrastim injections on white blood cell and platelet (PLT) recovery, adverse events, post-operative complications, and cost effectiveness after allogeneic hematopoietic stem cell transplantation (allo-HSCT).

Methods

Children who underwent allo-HSCT at our hospital from January 2014 to May 2017 due to thalassemia major, aplastic anemia, leukemia, and mucopolysaccharidosis were included. Among the children, 53 received xinruibai injections and 33 received filgrastim injections.

Results

There were no significant differences in the average time to neutrophil and platelet recovery, the incidence of post-operative complications after allo-HSCT, the number of red blood cell and PLT infusions, or the incidence of adverse events related to the injection between two groups (P >  0.05). The pain score was 3.06 (SD 0.41) for the xinruibai group and 25.18 (SD 6.22) for the filgrastim group, indicating significant differences between the two groups (P <  0.001). No difference was found in the hospitalization cost. The cost of the granulocyte-colony stimulating factor (G-CSF) was 257.11 ± 61.87 Euro in the xinruibai group and 214.79 ± 0.00 Euro in the filgrastim group, showing significant difference (P <  0.001).

Conclusions

Xinruibai injection was more convenient, simple, effective, and safer than filgrastim.

Autograft immune effector cells and survival in autologous peripheral blood hematopoietic stem cell transplantation

In addition to stem cells, T-cells, natural killer cells, dendritic cells, and monocytes are also collected and infused from the autograft in patients undergoing autologous peripheral blood hematopoietic stem cell transplantation. Recent reports have shown that these autograft immune effector cells can affect the clinical outcome postautologous peripheral blood hematopoietic stem cell transplantation. In this article, I will review the clinical impact on the survival of these autograft immune effector cells conferring the concept of autologous graft versus tumor effect.

Infusion of autograft natural killer cell/CD14+HLA-DRDIM cell ratio predicts survival in lymphoma post autologous stem cell transplantation

The infusion of autograft absolute lymphocyte count (A-ALC) and autograft natural killer cells (A-NKC) are prognostic factors for overall survival (OS) and PFS in non-Hodgkin's lymphoma (NHL) patients undergoing autologous peripheral blood hematopoietic stem cell transplantation (APBHSCT). The human monocytic CD14⁺HLA-DR^DIM cells are associated with worse prognosis in NHL. Thus, we investigated whether the autograft A-NKC/A-CD14⁺HLA-DR^DIM ratio predicts survival in NHL. In a total of 111 NHL patients, we analyzed apheresis collection samples for the content of A-NKC and A-CD14⁺HLA-DR^DIM. With a median follow-up of 57.2 months (range: 2.1-84.6 months), patients with an A-NKC/A-CD14⁺HLA-DR^DIM ratio of ⩾0.29 experienced superior OS (5-year OS rates of 84% (95% confidence interval (CI), 72-91%) vs 48% (95% CI, 34-62%), P<0.0002, respectively) and PFS (5-year PFS rates of 59% (95% CI, 47-71%) vs 32% (95% CI, 20-48%), P<0.002, respectively). Multivariate analysis revealed that A-NKC/A-CD14⁺HLA-DR^DIM ratio was an independent predictor for PFS (hazard ratio (HR)=0.56, 95% CI, 0.32-0.96, P<0.03) and OS (HR=0.34, 95% CI, 0.16-0.68, P<0.002). The A-NKC/A-CD14⁺HLA-DR^DIM ratio provides a platform to target specific autograft immune effector cells to improve clinical outcomes in NHL patients undergoing APBHSCT.

Interleukin-21 promotes thymopoiesis recovery following hematopoietic stem cell transplantation

BACKGROUND

Impaired T cell reconstitution remains a major deterrent in the field of bone marrow (BM) transplantation (BMT) due to pre-conditioning-induced damages inflicted to the thymi of recipient hosts. Given the previously reported thymo-stimulatory property of interleukin (IL)-21, we reasoned that its use post-BMT could have a profound effect on de novo T cell development.

METHODS

To evaluate the effect of IL-21 on de novo T cell development in vivo, BM derived from RAG2p-GFP mice was transplanted into LP/J mice. Lymphocyte reconstitution was first assessed using a hematological analyzer and a flow cytometer on collected blood samples. Detailed flow cytometry analysis was then performed on the BM, thymus, and spleen of transplanted animals. Finally, the effect of human IL-21 on thymopoiesis was validated in humanized mice.

RESULTS

Using a major histocompatibility complex (MHC)-matched allogeneic BMT model, we found that IL-21 administration improves immune reconstitution by triggering the proliferation of BM Lin^-Sca1⁺c-kit⁺ (LSK) subsets. The pharmacological effect of IL-21 also culminates in the recovery of both hematopoietic (thymocytes) and non-hematopoietic (stromal) cells within the thymi of IL-21-treated recipient animals. Although T cells derived from all transplanted groups proliferate, secrete various cytokines, and express granzyme B similarly in response to T cell receptor (TCR) stimulation, full regeneration of peripheral naïve CD4⁺ and CD8⁺ T cells and normal TCRvβ distribution could only be detected in IL-21-treated recipient mice. Astonishingly, none of the recipient mice who underwent IL-21 treatment developed graft-versus-host disease (GVHD) in the MHC-matched allogeneic setting while the graft-versus-tumor (GVT) effect was strongly retained. Inhibition of GVHD onset could also be attributed to the enhanced generation of regulatory B cells (B10) observed in the IL-21, but not PBS, recipient mice. We also tested the thymopoiesis-stimulating property of human IL-21 in NSG mice transplanted with cord blood (CB) and found significant improvement in de novo human CD3⁺ T cell development.

CONCLUSIONS

In sum, our study indicates that IL-21 represents a new class of unforeseen thymopoietin capable of restoring thymic function following BMT.

Prognostic relevance of lymphocytopenia, monocytopenia and lymphocyte-to-monocyte ratio in primary myelodysplastic syndromes: a single center experience in 889 patients

Current prognostic models for myelodysplastic syndromes (MDS), including the Revised International Prognostic Scoring System (IPSS-R), do not account for host immunity. We retrospectively examined the prognostic relevance of monocytopenia, lymphocytopenia and lymphocyte-to-monocyte ratio (LMR) in a cohort of 889 patients with primary MDS. After a median follow-up of 27 months, 712 (80%) deaths and 116 (13%) leukemic transformation were documented. In univariate analysis, subnormal absolute lymphocyte count (ALC) <0.9 × 10⁹/l; P=0.001), ALC<1.2 × 10⁹/l (P=0.0002), subnormal absolute monocyte count (AMC) <0.3 × 10⁹/l (P=0.0003), LMR (P⩽0.0001) and LMR⩾5 (P=0.03) were all associated with inferior overall survival. In multivariable analysis that included other risk factors, significance was retained for LMR (P=0.02) and became borderline for ALC <1.2 × 10⁹/l (P=0.06). Analysis in the context of IPSS-R resulted in P-values of 0.06 for ALC<1.2 × 10⁹/l, 0.7 for monocytopenia and 0.2 for LMR. Leukemia-free survival was not affected by ALC, AMC or LMR. The observations from the current study suggest a possible detrimental role for altered host immunity in primary MDS, which might partly explain the therapeutic benefit of immune-directed therapy, including the use of immune modulators; however, IPSS-R-independent prognostic value for either ALC or AMC was limited.

The Complexity of Targeting PI3K-Akt-mTOR Signalling in Human Acute Myeloid Leukaemia: The Importance of Leukemic Cell Heterogeneity, Neighbouring Mesenchymal Stem Cells and Immunocompetent Cells

Therapeutic targeting of PI3K-Akt-mTOR is considered a possible strategy in human acute myeloid leukaemia (AML); the most important rationale being the proapoptotic and antiproliferative effects of direct PI3K/mTOR inhibition observed in experimental studies of human AML cells. However, AML is a heterogeneous disease and these effects caused by direct pathway inhibition in the leukemic cells are observed only for a subset of patients. Furthermore, the final effect of PI3K-Akt-mTOR inhibition is modulated by indirect effects, i.e., treatment effects on AML-supporting non-leukemic bone marrow cells. In this article we focus on the effects of this treatment on mesenchymal stem cells (MSCs) and monocytes/macrophages; both these cell types are parts of the haematopoietic stem cell niches in the bone marrow. MSCs have unique membrane molecule and constitutive cytokine release profiles, and mediate their support through bidirectional crosstalk involving both cell-cell contact and the local cytokine network. It is not known how various forms of PI3K-Akt-mTOR targeting alter the molecular mechanisms of this crosstalk. The effect on monocytes/macrophages is also difficult to predict and depends on the targeted molecule. Thus, further development of PI3K-Akt-mTOR targeting into a clinical strategy requires detailed molecular studies in well-characterized experimental models combined with careful clinical studies, to identify patient subsets that are likely to respond to this treatment.

Fewer Circulating Natural Killer Cells 28 Days After Double Cord Blood Transplantation Predicts Inferior Survival and IL-15 Response

Natural Killer (NK) cell immune reconstitution after double umbilical cord blood transplantation (dUCBT) is rapid and thought to be involved in graft vs. leukemia (GvL) reactions. To investigate the role of NK cell recovery on clinical outcomes, the absolute number of NK cells at Day 28 after dUCBT was determined and patients with low numbers of NK cells had inferior two year disease-free survival (hazard ratio 1.96; p=0.04). A detailed developmental and functional analysis of the recovering NK cells was performed to link NK recovery and patient survival. The proportion of NK cells in each developmental stage was similar for patients with low, medium, and high Day 28 NK cell numbers. As compared to healthy controls, patients post-transplant showed reduced NK functional responses upon K562 challenge (CD107a, IFN-γ, and TNFα); however, there were no differences based on Day 28 NK cell number. Patients with low NK numbers had 30% less STAT5 phosphorylation in response to exogenous IL-15 (p=0.04) and decreased Eomes expression (p=0.025) compared to patients with high NK numbers. Decreased STAT5 phosphorylation and Eomes expression may be indicative of reduced sensitivity to IL-15 in the low NK cell group. Incubation of patient samples with IL-15 superagonist (ALT803) increased cytotoxicity and cytokine production in all patient groups. Thus, clinical interventions, including administration of IL-15 early after transplantation may increase NK cell number and function and, in turn, improve transplantation outcomes.

Relapse risk after autologous stem cell transplantation in patients with lymphoma based on CD34+ cell dose

It is unclear whether higher CD34 + cell doses infused for ASCT have any influence on survival or relapse in patients with lymphoma. We analyzed the correlation of infused CD34 + cell dose with relapse, survival, and hematopoietic recovery in 146 consecutive patients undergoing ASCT for lymphoma. Higher doses (>5 × 10⁶/kg) were significantly correlated with earlier hematopoietic recovery, fewer infectious episodes, lower transfusion needs. No differences were observed in lymphoma outcomes (4-year relapse incidence of 38% [95%CI: 29%-48%] in the lower dose group versus 51% [95%CI: 30%-69%] in the higher dose group, 10-year OS probabilities of 58% [95%CI: 48%-68%] versus 75% [95%CI: 59%-91%], 10-year DFS probabilities of 47% [95%CI: 37%-57%] versus 42% [95%CI: 23%-61%], p = NS for all outcomes). In this series, a higher infused CD34 + cell dose did not correlate with survival or relapse but correlated with earlier hematopoietic recovery and lower resource consumption.

Autologous Graft-versus-Tumor Effect: Reality or Fiction?

In contrast to allogeneic hematopoietic stem cell transplantation, the current dogma is not an evidence of graft-versus-tumor effect in autologous hematopoietic stem cell transplantation; thus, it is assumed that autologous hematopoietic stem cell transplantation only relies on the high-dose chemotherapy to improve clinical outcomes. However, recent studies argue in favor of the existence of an autologous graft-versus-tumor without the detrimental complications of graft-versus-host disease due to the nonspecific immune response from the infused donor alloreactive immune effector cells in allogeneic hematopoietic stem cell transplantation. Herein, this paper reviews the clinical evidence of an autologous graft-versus-tumor effect based on the autograft collected and infused host immune effector cells and host immunity recovery after autologous hematopoietic stem cell transplantation affecting clinical outcomes in cancer patients.

Adoptive transfer of activated marrow-infiltrating lymphocytes induces measurable antitumor immunity in the bone marrow in multiple myeloma

Successful adoptive T cell therapy (ACT) requires the ability to activate tumor-specific T cells with the ability to traffic to the tumor site and effectively kill their target as well as persist over time. We hypothesized that ACT using marrow-infiltrating lymphocytes (MILs) in multiple myeloma (MM) could impart greater antitumor immunity in that they were obtained from the tumor microenvironment. We describe the results from the first clinical trial using MILs in MM. Twenty-five patients with either newly diagnosed or relapsed disease had their MILs harvested, activated and expanded, and subsequently infused on the third day after myeloablative therapy. Cells were obtained and adequately expanded in all patients with anti-CD3/CD28 beads plus interleukin-2, and a median of 9.5 × 10(8) MILs were infused. Factors indicative of response to MIL ACT included (i) the presence of measurable myeloma-specific activity of the ex vivo expanded product, (ii) low endogenous bone marrow T cell interferon-γ production at baseline, (iii) a CD8(+) central memory phenotype at baseline, and (iv) the generation and persistence of myeloma-specific immunity in the bone marrow at 1 year after ACT. Achieving at least a 90% reduction in disease burden significantly increased the progression-free survival (25.1 months versus 11.8 months; P = 0.01). This study demonstrates the feasibility and efficacy of MILs as a form of ACT with applicability across many hematologic malignancies and possibly solid tumors infiltrating the bone marrow.

NK Cell Subgroups, Phenotype, and Functions After Autologous Stem Cell Transplantation

High-dose chemotherapy with consecutive autologous stem cell transplantation (autoSCT) is a well-established treatment option for patients suffering from malignant lymphoma or multiple myeloma. Natural killer (NK) cells are an important part of the immune surveillance, and their cell number after autoSCT is predictive for progression-free and overall survival. To improve knowledge about the role of NK cells after autoSCT, we investigated different NK cell subgroups, their phenotype, and their functions in patients treated with autoSCT. Directly after leukocyte regeneration (>1000 leukocytes/μl) following autoSCT, CD56⁺⁺ NK cells were the major NK cell subset. Surprisingly, these cells showed unusually high surface expression levels of CD57 and killer Ig-like receptors (KIRs) compared to expression levels before or at later time points after autoSCT. Moreover, these NK cells strongly upregulated KIR2DL2/3/S2 and KIR3DL1, whereas KIR2DL1/S1 remained constant, indicating that this cell population arose from more immature NK cells instead of from activated mature ones. Remarkably, NK cells were already able to degranulate and produce IFN-γ and MIP-1β upon tumor interaction early after leukocyte regeneration. In conclusion, we describe an unusual upregulation of CD57 and KIRs on CD56⁺⁺ NK cells shortly after autoSCT. Importantly, these NK cells were functionally competent upon tumor interaction at this early time point.

The prognostic role of the preoperative absolute lymphocyte count and absolute monocyte count in patients with resected advanced melanoma

OBJECTIVES

Published data have reported that components of the peripheral blood are significant prognostic factors in hematologic and solid malignancies. Thus, we sought to investigate if the preoperative absolute lymphocyte count (ALC) and absolute monocyte count (AMC) affects disease progression and survival after complete surgical resection of advanced malignant melanoma.

METHODS

We retrospectively reviewed records of 227 patients with resected advanced malignant melanoma (153 stage III and 74 stage IV) that were treated at the Mayo Clinic from 2000 to 2010. Survival analysis was performed using the Kaplan-Meier method, log-rank tests, and the Cox proportional hazards model for the univariate and multivariate analysis.

RESULTS

Surgically resected stage III melanoma patients with a preoperative AMC<0.6×10/L experienced a longer overall survival (OS) versus AMC≥0.6×10/L (median: 63.9 vs. 34.8 mo, respectively, P<0.008). Multivariate analysis showed AMC to be an independent predictor for OS in stage III patients. Stage IV resected melanoma patients with an ALC≥1.9×10/L experienced a superior median relapse-free survival (RFS) compared with patients with an ALC<1.9×10/L (median: 11.4 vs. 5.4 mo, respectively, P<0.006). Multivariate analysis showed ALC to be an independent predictor for RFS in stage IV patients.

CONCLUSIONS

These data showed that in surgically resected stage III melanoma, preoperative AMC is an independent prognostic factor for OS. In contrast, a higher preoperative ALC is an independent prognostic for longer RFS in surgically resected stage IV melanoma.

Methotrexate-associated lymphoproliferative disorders: management by watchful waiting and observation of early lymphocyte recovery after methotrexate withdrawal

No optimum treatment of iatrogenic immunodeficiency-associated lymphoproliferative disorders due to methotrexate in patients with rheumatoid arthritis (MTX-LPD) has yet been established, although MTX withdrawal is known to have a substantial effect on tumor regression. Here, we retrospectively analyzed 20 cases of MTX-LPD. Tumor shrinkage occurred in 18 of 20 cases, but only following MTX withdrawal. This tumor regression ratio was considerably better than in previous reports, and appeared due to longer "watchful waiting." Lymphocyte recovery at 2 weeks after MTX withdrawal was significantly higher in cases with tumor regression in 1 month than in those without tumor regression (p = 0.001). Median time to maximal efficacy after MTX cessation in cases without chemotherapy was 12 weeks (range 2-76). In conclusion, watchful waiting for a longer period after MTX cessation with observation of early lymphocyte recovery and uninterrupted continuation of other anti-rheumatoid drugs may be an acceptable management plan for MTX-LPD.

Effects of cytarabine on activation of human T cells - cytarabine has concentration-dependent effects that are modulated both by valproic acid and all-trans retinoic acid

Background

Cytarabine is used in the treatment of acute myeloid leukemia (AML). Low-dose cytarabine can be combined with valproic acid and all-trans retinoic acid (ATRA) as AML-stabilizing treatment. We have investigated the possible risk of immunotoxicity by this combination. We examined the effects of cytarabine combined with valproic acid and ATRA on in vitro activated human T cells, and we tested cytarabine at concentrations reached during in vivo treatment with high doses, conventional doses and low doses.

Methods

T cells derived from blood donors were activated in vitro in cell culture medium alone or supplemented with ATRA (1 μM), valproic acid (500 or 1000 μM) or cytarabine (0.01-44 μM). Cell characteristics were assessed by flow cytometry. Supernatants were analyzed for cytokines by ELISA or Luminex. Effects on primary human AML cell viability and proliferation of low-dose cytarabine (0.01-0.5 μM) were also assessed. Statistical tests include ANOVA and Cluster analyses.

Results

Only cytarabine 44 μM had both antiproliferative and proapoptotic effects. Additionally, this concentration increased the CD4:CD8 T cell ratio, prolonged the expression of the CD69 activation marker, inhibited CD95L and heat shock protein (HSP) 90 release, and decreased the release of several cytokines. In contrast, the lowest concentrations (0.35 and 0.01 μM) did not have or showed minor antiproliferative or cytotoxic effects, did not alter activation marker expression (CD38, CD69) or the release of CD95L and HSP90, but inhibited the release of certain T cell cytokines. Even when these lower cytarabine concentrations were combined with ATRA and/or valproic acid there was still no or minor effects on T cell viability. However, these combinations had strong antiproliferative effects, the expression of both CD38 and CD69 was altered and there was a stronger inhibition of the release of FasL, HSP90 as well as several cytokines. Cytarabine (0.01-0.05 μM) showed a dose-dependent antiproliferative effect on AML cells, and in contrast to the T cells this effect reached statistical significance even at 0.01 μM.

Conclusions

Even low levels of cytarabine, and especially when combined with ATRA and valproic acid, can decrease T cell viability, alter activation-induced membrane-molecule expression and decrease the cytokine release.

Electronic supplementary material

The online version of this article (doi:10.1186/s40360-015-0012-2) contains supplementary material, which is available to authorized users.

Absolute lymphocyte count recovery at 1 month after transplantation predicts favorable outcomes of patients with hepatocellular carcinoma

BACKGROUND AND AIMS

Absolute lymphocyte count (ALC) and the recovery of ALC after treatment have been identified as a prognostic biomarker for several malignancies. In this study, we aimed to investigate the prognostic role of peritransplant ALC and ALC recovery after liver transplantation (LT) in hepatocellular carcinoma (HCC) patients.

METHODS

A total of 269 HCC patients undergoing LT were enrolled in our study. Clinicopathological data were retrospectively collected and reviewed. Peritransplant ALC and the change of ALC (2 weeks, 1 month, 3 months post-LT) were carefully monitored. All potential risk factors were analyzed by univariate and multivariate cox regression analysis.

RESULTS

Over a mean follow-up of 35.9 months, 120 recurrences and 89 deaths were recorded. In the multivariate analysis, HCC with ALC no recovery at 1 month after LT (P < 0.001), high pretransplant alpha fetoprotein (P = 0.010), total tumor size > 8 cm (P = 0.003), and beyond Milan criteria (P < 0.001) were four independent risk factors for HCC recurrence. For overall survival (OS) after LT, ALC no recovery at 1 month after LT (P = 0.003), total tumor size > 8 cm (P = 0.011), pretransplant albumin < 2.8 g/dL (P = 0.049), model of end-stage liver disease score > 15 (P = 0.017), and beyond Milan criteria (P = 0.001) were significantly related to poor OS. When subgroup analyses were performed according to the Milan criteria, the results showed that the recovery of ALC at 1 month after LT still indicated longer recurrence-free survival (RFS) (P < 0.001) and OS (P = 0.005) beyond Milan criteria as well as RFS (P < 0.001) within Milan criteria, but not OS (P = 0.157) within Milan criteria.

CONCLUSIONS

ALC recovery at 1 month after LT indicated favorable outcomes of HCC patients.

General and Virus-Specific Immune Cell Reconstitution after Double Cord Blood Transplantation

Cord blood transplantation (CBT) is curative for many patients with hematologic malignancies but is associated with delayed immune recovery and an increased risk of viral infections compared with HLA-matched bone marrow or peripheral blood progenitor cell transplantation. In this study we evaluated the significance of lymphocyte recovery in 125 consecutive patients with hematologic malignancies who underwent double-unit CBT (DUCBT) with an antithymocyte globulin-containing regimen at our institution. A subset of 65 patients was prospectively evaluated for recovery of T, natural killer (NK), and B cells, and in 46 patients we also examined viral-specific T cell recovery against adenovirus, Epstein-Barr virus, cytomegalovirus, BK virus, respiratory syncytial virus, and influenza antigen. Our results indicate that in recipients of DUCBT, the day 30 absolute lymphocyte count is highly predictive of nonrelapse mortality and overall survival. Immune recovery post-DUCBT was characterized by prolonged CD8+ and CD4+ T lymphopenia associated with preferential expansion of B and NK cells. We also observed profound delays in quantitative and functional recovery of viral-specific CD4+ and CD8+ T cell responses for the first year post-CBT. Taken together, our data support efforts aimed at optimizing viral-specific T cell recovery to improve outcomes post-CBT.

Up-regulation of anti-apoptotic genes confers resistance to the novel anti-leukaemic compound PEP005 in primary AML cells

We showed previously that PEP005 induced apoptosis in leukaemic cell lines and blasts from patients with acute myeloid leukaemia (AML). Here we assess the anti-leukeamic effects of PEP005 in vivo and determine the mechanism of resistance of PEP005 non-responsive cells. We used 2 human xenograft mouse models of AML to assess the anti-leukaemic effects of PEP005 in vivo. Expression microarray analysis of primary AML blasts following treatment with PEP005 was used to determine patterns of gene expression that conferred resistance. PEP005 significantly reduced tumour burden in two human leukaemia mouse xenograft models. We also assessed responsiveness of 33 AML samples to PEP005, with 78% of the samples entering apoptosis at 100nM. Resistance to PEP005 was not restricted to a particular AML subtype. Expression microarray analysis of resistant samples following treatment with PEP005 revealed a significant up regulation of the anti-apoptotic genes Bcl-2A1, Mcl-1, and PHLDA1 which was verified using RT-PCR. We conclude that PEP005 shows broad efficacy against AML subtypes and that up regulation of anti-apoptotic genes underlies resistance to this agent and could be used to screen for patients unlikely to benefit from a therapeutic regime involving PEP005.

Infused autograft lymphocyte to monocyte ratio and survival in diffuse large B cell lymphoma

Infused autograft absolute lymphocyte count is a prognostic factor for survival after autologous peripheral hematopoietic stem cell transplantation (APHSCT) for diffuse large B cell lymphoma (DLBCL). CD14(+) HLA-DR(low/neg) immunosuppressive monocytes affect tumor growth by suppressing host antitumor immunity. Thus, we set out to investigate if the infused autograft lymphocyte to monocyte ratio (A-LMR), as a biomarker of host immunity (ie, lymphocytes) and immunosuppression (ie, monocytes), affects survival after APHSCT. From 1994 to 2012, 379 DLBCL patients who underwent APHSCT were studied. The 379 patients were randomly divided into a training set (n = 253) and a validation set (n = 126). Receiver operating characteristic and area under the curve identified an A-LMR ≥1 as the best cut-off value, which was validated by the k-fold cross-validation in the training set. Multivariate analysis showed A-LMR to be an independent prognostic factor for survival in the training set. Patients with an A-LMR ≥ 1.0 experienced superior overall survival (OS) compared with patients with an A-LMR <1.0 (median OS: 167.2 versus 17.6 months; 5-year OS: 73% [95% confidence interval (CI), 63% to 80%] versus 30% [95% CI, 2% to 38%], P < .0001, respectively) in the training set. In the validation set, an A-LMR ≥ 1 showed a median OS of 181.2 months versus 19.5 months for an A-LMR <1, and 5-year OS rates of 67% (95% CI, 52% to 79%) versus 35% (95% CI, 25% to 47%), P < .0001, respectively. The A-LMR provides a platform to engineer immunocompetent autograft to improve clinical outcomes in DLBCL patients undergoing APHSCT.

Lymphocyte subset recovery and outcome after autologous hematopoietic stem cell transplantation for plasma cell myeloma

Rapid immune reconstitution--particularly of natural killer cells (NK cells)--after allogeneic hematopoietic stem cell transplantation (HSCT) is associated with protection from relapse. Whether such an association also exists after autologous stem cell transplantation is less clear. We retrospectively assessed lymphocyte subsets after autologous HSCT in 114 patients and correlated lymphocyte recovery with outcome. CD8 T cell and NK cell counts recovered rapidly to pretransplantation levels, whereas B cell and CD4 T cell recovery were delayed. Compared with patients with low NK cells (<100/uL), high NK cell count at 1 month after HSCT was associated with significantly prolonged progression-free survival: for NK cells 100 to 200/uL hazard ratio [HR], .33 (95% confidence interval [CI]; .16 to .80; P = .004); for NK cells > 200/μL HR, .27 (95% CI, .13 to .58; P = .001). No significant protective effects were associated with rapid recovery of any other lymphocyte subset. None influenced overall survival (OS) or time to next treatment. Early NK cell recovery is associated with better progression-free survival after autologous HSCT. The failure to detect an effect on OS might be due to the salvage strategies available to these patients.

Lymphocyte recovery and infused CD34+ cells dose: Effect on the evolution after stem cell autotransplantation

BACKGROUND AND OBJECTIVE

The number of infused CD34+cells (CD34+i) has been associated with absolute lymphocyte count (ALC) and the outcome undergoing autologous hematopoietic stem cell transplantation (HSCT) in patients with hematologic malignancies. The study's aim was to analyze the relationship between CD34+i, ALC and prognosis in this patients.

PATIENTS AND METHOD

Medical records of 163 patients receiving HSCT between 2005 and 2012 were reviewed.

RESULTS

We found significant and inversely proportional relationship between the CD34+i and the days required to reach ALC≥500/μl according to the regression line: days=-0.981×number of CD34+i+18.09.

CONCLUSIONS

We have obtained a predictive model of lymphocyte recovery based recovery of CD34+i.

Proceedings from the National Cancer Institute's Second International Workshop on the Biology, Prevention, and Treatment of Relapse after Hematopoietic Stem Cell Transplantation: part II. Autologous Transplantation-novel agents and immunomodulatory strategies

In the National Cancer Institute's Second International Workshop on the Biology, Prevention, and Treatment of Relapse after Hematopoietic Stem Cell Transplantation, the Scientific/Educational Session on Autologous Transplantation addressed the role of novel agents and immunomodulatory strategies in management of relapse after autologous hematopoietic stem cell transplantation (AHSCT). Concepts were illustrated through in-depth discussion of multiple myeloma, with broader discussion of areas relevant for relapse of other malignancies as well as in the setting of allogeneic transplantation. Dr. Hari provided an overview of the epidemiology of relapse after AHSCT in multiple myeloma, addressing clinical patterns, management implications, and treatment options at relapse, highlighting the implications of novel therapeutic agents in initial, maintenance, and relapse treatment. Dr. Avigan discussed current concepts in tumor vaccine design, including whole cell and antigen-specific strategies, use of an AHSCT platform to reverse tumor-associated immunosuppression and tolerance, and combining vaccines with immunomodulatory agents to promote establishment of durable antitumor immunity. Dr. Hsu reviewed the immunogenetics of natural killer (NK) cells and general NK biology, the clinical importance of autologous NK activity (eg, lymphoma and neuroblastoma), the impact of existing therapies on promotion of NK cell activity (eg, immunomodulatory drugs, monoclonal antibodies), and strategies for enhancing autologous and allogeneic NK cell effects through NK cell gene profiling.

Circulating T cells in patients with untreated acute myelogenous leukemia are heterogeneous and can be activated through the CD3/TCR complex

T lymphocyte defects may contribute to the immune insufficiency seen in acute myelogenous leukemia (AML). We therefore characterized the T cell system for untreated AML patients. T lymphocyte subsets were analyzed by flow cytometry for 45 AML patients. The in vitro interferon-gamma (IFNgamma) release in response to stimulation with anti-CD3 plus anti-CD28 in the presence of autologous AML cells was examined for 31 patients. The majority of circulating lymphocytes were CD3(+)T cells, and CD19(+)B cells usually constituted < 10% of the lymphocytes. Most T cells expressed the alphabeta T cell receptor (TCRalphabeta(+)), and only a minority of the cells was TCRgammadelta(+). Both CD4(+) and CD8(+)T cells were detected, the CD4:CD8 ratio showed a wide variation but was generally >1.0. The majority of CD4(+) and CD8(+)T cells were CD45RA(+) cells. The T cells could be stimulated to release IFNgamma in response to anti-CD3 plus anti-CD28 ligation even in the presence of excess autologous AML blasts, and for a subset of patients (6 of 27) these IFNgamma levels could be further increased by the novel protein kinase C (PKC) agonist PEP005. In conclusion, circulating T cells in patients with untreated AML are mainly CD4(+) or CD8(+) TCRalphabeta(+); both CD45RA(+) and CD45R0(+) can be detected, and these cells can be activated through the CD3/TCR complex even in the presence of excess AML cells. For a subset of patients T cell responsiveness can be further increased by targeting PKC and these data therefore suggest that T cell function is not inhibited in AML patients.

Achieving graft-versus-tumor effect in brain tumor patients: from autologous progenitor cell transplant to active immunotherapy

Success in treating aggressive brain tumors like glioblastoma multiforme and medulloblastoma remains challenging, in part because these malignancies overcome CNS immune surveillance. New insights into brain tumor immunology have led to a rational development of immunotherapeutic strategies, including cytotoxic Tlymphocyte therapies and dendritic cell vaccines. However, these therapies are most effective when applied in a setting of minimal residual disease, so require prior use of standard cytotoxic therapies or cytoreduction by surgery. Myeloablative chemotherapy with autologous hematopoietic cell transplantation (autoHCT) can offer a platform upon which different cellular therapies can be effectively instituted. Specifically, this approach provides an inherent 'chemical debulking' through high-dose chemotherapy and a graft-versus-tumor effect through an autologous T-cell replete graft. Furthermore, autoHCT may be beneficial in 'resetting' the body's immune system, potentially 'breaking' tumor tolerance, and in providing a 'boost' of immune effector cells (NK cells or cytotoxic T lymphocytes), which could augment desired anti-tumor effects. As literature on the use of autoHCT in brain tumors is scarce, aspects of immunotherapies applied in non-CNS malignancies are reviewed as potential therapies that could be used in conjunction with autoHCT to eradicate brain tumors.

Cellular immunotherapy for plasma cell myeloma

Allogeneic hematopoietic cell transplantation for plasma cell myeloma can lead to graft-vs-myeloma immunity and long-term survivorship, but limited efficacy and associated toxicities have prevented its widespread use. Cellular immunotherapies seek to induce more specific, reliable and potent antimyeloma immune responses with less treatment-related risk than is possible with allogeneic transplantation. Strategies under development include infusion of vaccine-primed and ex vivo expanded/costimulated autologous T cells after high-dose melphalan, genetic engineering of autologous T cells with receptors for myeloma-specific epitopes, administration of DC/plasma cell fusions and administration expanded marrow-infiltrating lymphocytes. In addition, novel immunomodulatory drugs such as inhibitors of the programmed death-1 T cell regulatory pathway may synergize with cellular immunotherapies.

Natural killer cell receptor repertoire is comparable amongst newly diagnosed acute myeloid leukemia of different French-American-British subtypes, risk categories and chemosensitivities

We studied the natural killer (NK) receptor repertoire by flow cytometry for 78 patients with newly diagnosed acute myeloid leukemia (AML) and correlated the expression with their biological and clinical characteristics. CD3-CD56+ NK cells constituted a median of 11.68% of the lymphocyte subset. The NK receptors including the killer immunoglobulin-like receptors, natural cytotoxicity receptors and C-type lectin receptors were comparable amongst the various French-American-British (FAB) subtypes and amongst patients in the better, intermediate and poor risk categories. Neither was there any difference in NK receptor repertoire between patients who achieved a remission with induction chemotherapy and those who were chemorefractory, indicating the absence of a prognostic impact of NK receptor repertoire at the time of diagnosis of AML. Compared with NK cells from 16 healthy donors, most of the NK receptors were expressed at a significantly lower level, suggesting a defective NK cell population as a cause or result of AML.

Prognostic impact of absolute lymphocyte counts at the end of remission induction in childhood acute lymphoblastic leukemia

BACKGROUND

Absolute lymphocyte counts (ALC) during treatment have been associated with outcome in children and adults with hematologic malignancies. However, the impact of ALC relative to that of other prognostic factors on the outcome of children with acute lymphoblastic leukemia (ALL) treated in recent trials is unknown.

METHODS

Outcomes of 399 patients aged ≤18 years with newly diagnosed ALL who were enrolled in the Total Therapy XV study at St. Jude Children's Research Hospital were analyzed according to ALC at the end of remission induction therapy.

RESULTS

An ALC ≥500 cells/μL was significantly more prevalent among patients with B-lineage ALL, in those with favorable presenting features, and in those who achieved negative minimal residual disease (MRD) status on day 43 of treatment. Both overall survival (OS) and event-free survival (EFS) were superior among patients with higher ALC, but only the association with OS was statistically significant in a univariate analysis. In multivariable analyses, ALC was not a significant predictor of outcome after controlling for age, leukocyte count, lineage, risk group, and MRD status at the end of induction (P > .1 for all comparisons). However, among MRD-negative patients, those with low ALC had a 5-year OS rate of 84.2% ± 8.9% versus 97.3% ± 1.0% for patients with higher ALC (P = .036).

CONCLUSIONS

ALC at the end of induction is related to favorable presenting features and good initial treatment response but does not independently predict outcome in the context of contemporary, MRD-guided therapy.

The B7 homologues and their receptors in hematologic malignancies

The B7 homologues and their receptors regulate both peripheral tolerance and adaptive immunity. This field is rapidly evolving as new ligands and receptors are being identified. Much of the work supporting their role in the regulation of host anti-tumor immunity has been derived from experimental models and clinical trials in solid malignancies. However, a growing body of evidence demonstrates that the B7-H family has important immunologic and non-immunologic functions in a variety of hematologic malignancies. Herein, we will review recent evidence that supports the therapeutic targeting of the B7 homologues in hematologic malignancies.

Lymphocyte subset analysis for the assessment of treatment-related complications after autologous stem cell transplantation in multiple myeloma

BACKGROUND AIMS

The aim of this study was to investigate the correlation between infused lymphocyte populations and lymphocyte subsets at engraftment, and the early clinical implications of lymphocyte subset recovery after autologous stem cell transplantation (ASCT) in multiple myeloma (MM).

METHODS

We examined the lymphocyte populations of infused autografts and the lymphocyte subsets of peripheral blood at engraftment from 50 patients using flow cytometry. Each subset was grouped as low (below median) and high (above median) to examine the correlation with mucositis of grade 3 or more and the occurrence of infections and cytomegalovirus (CMV) reactivation.

RESULTS

Using Spearman correlation coefficients, we found that cell doses of infused CD8(+) (P = 0.042) and CD19(+) cells (P = 0.044) were significantly associated with the absolute lymphocyte count (ALC) at engraftment. The dose of infused CD34(+) cells was not associated with the change of lymphocyte subsets except for an inverse correlation with CD4(+) cells (P = 0.006). After adjusting for potential variables in univariate analysis, multivariate analyzes revealed that the lower ratio of infused CD4(+) to CD8(+) cells (P = 0.030) was an independent factor for severe mucositis. Of lymphocyte subsets at engraftment, a higher frequency of CD3(+) (P = 0.024) and a lower frequency of CD56(+) (P = 0.020) were independent predictors for infections after engraftment. A higher frequency of CD8(+) cells (P = 0.041) and a lower ratio of CD4(+) to CD8(+) (P = 0.021) were independent predictors for CMV reactivation.

CONCLUSIONS

Our data suggest that lymphocyte subset analysis of infused autograft and peripheral blood at engraftment may provide new predictors for early complications after ASCT in patient with MM.

Future perspectives: should Th17 cells be considered as a possible therapeutic target in acute myeloid leukemia patients receiving allogeneic stem cell transplantation?

Th17 cells seem to promote proinflammatory effects, and their development seems to depend on intracellular signaling initiated by IL1β, supported by IL6 and IL23 and mediated by STAT3 and RORC2. Even though primary human AML cells may affect Th17 development through their constitutive cytokine release, the levels of circulating Th17 cells in older patients with untreated AML do not differ from healthy controls and show only minor variations during and following conventional intensive chemotherapy. IL17-A is the signature cytokine of Th17 cells, but in vitro studies have failed to demonstrate a direct antileukemic effect of IL17 on primary human AML cells for most patient samples. However, several observations suggest that Th17 cells mediate antileukemic effects through other mechanisms and are important in allogeneic stem cell transplantation. Firstly, genetic variants in IL23/Th17 pathway have a prognostic impact with regard to both development of GVHD and posttransplant infections. Secondly, circulating IL17-secreting cells are detected during early posttransplant pancytopenia, and their ability to release IL17 is associated with later GVHD. Thirdly, a high number of Th17 cells in allogeneic stem cell grafts are associated with later acute GVHD, levels of circulating Th17 cells are increased at the onset of acute GVHD, and these levels normalize during treatment. In the present article, we review previous studies of Th17 cells in AML and in the development of GVHD, possible therapeutic strategies and available therapeutic tools for targeting of Th17 cells.

[Absolute lymphocyte count as a prognostic factor in children with acute lymphoblastic leukemia]

INTRODUCTION

Recent studies have suggested that the absolute lymphocyte count (ALC) may be a prognostic indicator in malignant diseases, in that those patients who have higher ALC at certain times during treatment may have a better chance of survival. The influence of T cells and natural killer cells in the immune system of the patient with cancer as a response to cancer cells is particularly noted.

MATERIALS AND METHOD

We prospectively assessed the prognostic value of absolute lymphocytic count (ALC) in 105 pediatric patients with acute lymphoblastic leukemia (ALL), treated in the Cuban Immunology and Hematology Institute from 1995 to 2008. ALC was studied at days 15 (ALC-15) and 28 (ALC-28) of treatment.

RESULTS

In our patients, 1000 cells/uL was the median ALC value for patients who relapsed or died. Using 1000/uL we found that ALL patients with an ALC-15 <1000 cells/μl had a 5-year relapse free survival (RFS) of 51%. In contrast, an ALC-15 >1000 cells/uL showed an excellent prognosis, with a 5-year RFS of 83% (p=0.02). Similarly in our study, an ALC-28 <1000 cells/μl predicted a 5-year overall survival (OS) of 66%, whereas an ALC-28 >1000 cells/μl predicted excellent outcome, with a 5-year OS of 86% (p=0.01). Importantly, ALC is also a strong predictor in multivariate analysis with known prognostic factors. ALC is a simple, statistically powerful measurement for patients with de novo ALL.

CONCLUSIONS

The results, when combined with previous studies, demonstrate that ALC is a powerful new prognostic factor for a range of malignancies.

Immunosuppression in patients with high-grade gliomas treated with radiation and temozolomide

PURPOSE

Patients with high-grade gliomas (HGG) routinely receive radiation, temozolomide, and glucocorticoids. As each of these is immunosuppressive, we conducted a prospective, multicenter study to follow CD4 counts over time and determine whether low CD4 counts were associated with adverse outcomes.

EXPERIMENTAL DESIGN

Patients with newly diagnosed HGG had CD4 counts drawn before initiating standard therapy and monthly thereafter for 1 year. Information on hospitalizations, infections, glucocorticoid use, survival, and cause of death were also collected.

RESULTS

Ninety-six evaluable patients were accrued [85% glioblastoma, median age of 57, median Karnofsky performance status (KPS) = 90]. The median CD4 count before radiation and temozolomide treatment was 664 cells/mm(3). The CD4 count nadir occurred 2 months after initiating therapy when 73% of patients had CD4 counts less than 300 cells/mm(3) and 40% had less than 200 cells/mm(3). CD4 counts remained low throughout the year of follow-up. Patients with CD4 counts less than 200 cells/mm(3)at 2 months had shorter survival than those with higher counts (median: 13.1 vs. 19.7 months, P = 0.002). Median survival was related to CD4 toxicity grades (I = 23.8 months, II = 19.7 months, III-IV = 13.1 months, P = 0.009). The adjusted HR for death attributable to 2-month CD4 count below 200 was 1.66 (P = 0.03). Eighty-eight percent of deaths resulted from disease progression, whereas only 2.5% were due to infection.

CONCLUSIONS

Severe reductions in CD4 counts in patients with newly diagnosed HGG treated with radiation and temozolomide treatment are common, treatment-related, long-lasting, and associated with early death from tumor progression.

Novel mobilization strategies to enhance autologous immune effector cells in multiple myeloma

The immune system plays a critical role determining the outcomes in transplanted multiple myeloma patients, since enhanced lymphocyte recovery results in improved survival. Since mobilization regimens influence the cellular subsets collected and infused for transplant, these regimens may determine immune recovery following transplant. We hypothesized that a mobilized stem cell product harboring an increased number of lymphocytes would enhance immune recovery following autologous stem cell infusion, increase lymphocyte recovery, and improve clinical outcomes. We designed a phase I immune mobilization trial using IL-2 and growth factors to increase the number of lymphocytes within the stem cell product. This regimen efficiently mobilized CD34+ progenitor cells (median: 3.6 x 10(6) cells/kg; range 1.9-6.6 x 10(6) cells/kg) and improved the immune properties of the mobilized stem cells, including an increase in CD8+ T cells expressing an NK activating receptor called NKG2D (P less than 0.004), cells that are extremely potent at killing myeloma cells using non-MHC-I restricted and TCR-independent mechanisms. Novel mobilization techniques can improve the mobilized graft and may improve clinical outcomes in myeloma patients.

Prognostic significance of early lymphocyte recovery in pediatric osteosarcoma

BACKGROUND

Evidence suggests early lymphocyte recovery after chemotherapy predicts superior outcome for patients with cancer, a phenomenon not previously investigated in osteosarcoma. This study determined the prognostic significance of early lymphocyte recovery for pediatric patients with osteosarcoma.

PROCEDURES

We reviewed data of 19 consecutive patients treated for osteosarcoma at our institution from 1997 to 2007. After initial chemotherapy, patients were separated into two groups: early versus late lymphocyte recovery, using a threshold absolute lymphocyte count of ≥ 800 cells/µl on day 14 (ALC-14).

RESULTS

The 5-year overall survival (OS) for our cohort was 73.7% [± 10.1 standard error (SE)]. Thirteen patients (68%) had an ALC-14 ≥ 800 cells/µl, with 12/13 alive and 5-year OS of 92.3% (± 7.4 SE). In contrast, six patients (32%) had an ALC-14 < 800 cells/µL, with 1/6 alive and 5-year OS of 33.3% (± 19.2 SE). The difference is statistically significant (P = 0.0013, log-rank test). Two patients presented with multifocal disease at diagnosis, had late lymphocyte recovery and died. One patient presented with metastatic disease, had early lymphocyte recovery and is alive. Six patients developed relapsed disease with a 5-year OS of 33.3% (± 19.2 SE). The majority (5/6) of patients with relapsed disease died while on active therapy. The only survivor in this group had an ALC-14 > 800 cells/µl and recently completed relapse therapy.

CONCLUSIONS

These data demonstrate that early lymphocyte recovery represents a significant prognostic indicator for osteosarcoma. Early identification and risk stratification therapy based on the ALC-14 threshold may improve outcomes and our knowledge of this disease.

Lymphocyte recovery predicts outcomes in cord blood and T cell-depleted haploidentical stem cell transplantation

Alternative donor stem cell transplantation from cord blood or haploidentical peripheral blood donors is increasingly being used for patients who lack a matched related or unrelated donor. A higher nonrelapse mortality (NRM) rate has been noted with these 2 types of transplants, primarily because of infectious complications. Here, we hypothesized that the time to lymphocyte recovery (absolute lymphocyte count [ALC] of ≥1000/μL for the first 3 consecutive days) after transplant correlates with outcomes. We retrospectively analyzed 65 consecutive patients treated at our institution with cord blood (n = 37) and haploidentical (n = 28) transplantation with myeloablative fludarabine, melphalan, and thiotepa conditioning. Patients with lymphocyte recovery at day 60 posttransplant were more likely to survive long term than those without lymphocyte recovery. In multivariate analysis, ALC recovery was the only independent prognostic factor associated with mortality; patients without ALC recovery were 10.5 times (95% confidence interval [CI]: 4.3-25.4) more likely to die than those with ALC recovery (P < .0001). This difference appeared to be related to NRM (hazard ratio [HR] = 0.1, 95% CI: 0.02-0.6, P = .008), whereas ALC recovery did not influence the rate of disease relapse. These results suggest that ALC recovery is an important prognostic indicator for patients treated with cord blood and T cell-depleted peripheral haploidentical transplants.

Autograft mediated adoptive immunotherapy of cancer in the context of autologous stem cell transplantation

The infused stem cell autograft in autologous stem cell transplantation (ASCT) has been viewed mainly as hematologic rescue from the myelosuppressive side effect of conditioning regimens. However, recent reports have shown that the immune effector cells collected at the same time as the stem cells can produce an autologous graft-versus-tumor effect, similar to the graft-versus-tumor effect seen in allogeneic stem cell transplantation without the detrimental effects of graft-versus-host disease. In this article, we review the different immune effector cells collected and infused from the stem cell autograft and their association with clinical outcome post-ASCT, suggesting that ASCT can be viewed not only as a therapeutic maneuver to recover bone marrow function after deliver high-dose chemotherapy, but also as an adoptive immunotherapeutic intervention capable of eradicating residual tumor cells in patients with cancer.

Harnessing the effect of adoptively transferred tumor-reactive T cells on endogenous (host-derived) antitumor immunity

Adoptive T cell transfer therapy, the ex vivo activation, expansion, and subsequent administration of tumor-reactive T cells, is already the most effective therapy against certain types of cancer. However, recent evidence in animal models and clinical trials suggests that host conditioning interventions tailored for some of the most aggressive and frequent epithelial cancers will be needed to maximize the benefit of this approach. Similarly, the subsets, stage of differentiation, and ex vivo expansion procedure of tumor-reactive T cells to be adoptively transferred influence their in vivo effectiveness and may need to be adapted for different types of cancer and host conditioning interventions. The effects of adoptively transferred tumor-reactive T cells on the mechanisms of endogenous (host-derived) antitumor immunity, and how to maximize their combined effects, are further discussed.

Early lymphocyte recovery after intensive timed sequential chemotherapy for acute myelogenous leukemia: peripheral oligoclonal expansion of regulatory T cells

Few published studies characterize early lymphocyte recovery after intensive chemotherapy for acute myelogenous leukemia (AML). To test the hypothesis that lymphocyte recovery mirrors ontogeny, we characterized early lymphocyte recovery in 20 consecutive patients undergoing induction timed sequential chemotherapy for newly diagnosed AML. Recovering T lymphocytes were predominantly CD4(+) and included a greatly expanded population of CD3(+)CD4(+)CD25(+)Foxp3(+) T cells. Recovering CD3(+)CD4(+)CD25(+)Foxp3(+) T cells were phenotypically activated regulatory T cells and showed suppressive activity on cytokine production in a mixed lymphocyte reaction. Despite an initial burst of thymopoiesis, most recovering regulatory T cells were peripherally derived. Furthermore, regulatory T cells showed marked oligoclonal skewing, suggesting that their peripheral expansion was antigen-driven. Overall, lymphocyte recovery after chemotherapy differs from ontogeny, specifically identifying a peripherally expanded oligoclonal population of activated regulatory T lymphocytes. These differences suggest a stereotyped immunologic recovery shared by patients with newly diagnosed AML after induction timed sequential chemotherapy. Further insight into this oligoclonal regulatory T-cell population will be fundamental toward developing effective immunomodulatory techniques to improve survival for patients with AML.

Immune mobilization of autologous blood progenitor cells: direct influence on the cellular subsets collected

BACKGROUND AIMS

A phase I trial examined the ability of immunotherapy to mobilize progenitor and activated T cells.

METHODS

Interleukin (IL)-2 was administered subcutaneously for 11 days, with granulocyte (G)-colony-stimulating factor (CSF) (5 mcg/kg/day) and granulocyte-macrophage (GM)-CSF (7.5 mcg/kg/day) added for the last 5 days. Leukapheresis was initiated on day 11. Thirteen patients were treated (myeloma n = 11, non-Hodgkin's lymphoma n = 2).

RESULTS

Toxicities were minimal. IL-2 was stopped in two patients because of capillary leak (n = 1) and diarrhea (n = 1). Each patient required 2.5 leukaphereses (median; range 1-3) to collect 3.2 x 10⁶ CD34+ cells/kg (median; range 1.9-6.6 x 10⁶/kg). Immune mobilization increased the number of CD3+ CD8+ T cells (P = 0.002), CD56+ natural killer (NK) cells (P = 0.0001), CD8+ CD56+ T cells (P = 0.002) and CD4+ CD25+ cells (P = 0.0001) compared with cancer patients mobilized with G-CSF alone. There was increased lysis of myeloma cells after 7 days (P = 0.03) or 11 days (P = 0.02). The maximum tolerated dose of IL-2 was 1 x 10⁶ IU/m²/day.

CONCLUSIONS

Immune mobilization is well tolerated with normal subsequent marrow engraftment. As cells within the graft influence lymphocyte recovery, an increased number of functional lymphocytes may result in more rapid immune reconstitution.