Early lymphocyte recovery predicts superior survival after autologous hematopoietic stem cell transplantation in multiple myeloma or non-Hodgkin lymphoma

Plerixafor-based mobilization and mononuclear cell counts in graft increased the risk of engraftment syndrome after autologous hematopoietic stem cell transplantation

Engraftment syndrome (ES) is one of the most common complications in the early phase after autologous hematopoietic stem cell transplantation (ASCT), and we aimed to evaluate the incidence and risk factors for ES patients receiving ASCT in the era of plerixafor-based mobilization. A total of 294 were enrolled, and 16.0% (n = 47) experienced ES after ASCT. The main clinical manifestations were fever (100%), diarrhea (78.7%), skin rash (23.4%), and hypoxemia/pulmonary edema (12.8%). Plerixafor-based mobilization was associated with higher counts of CD3+ cells, CD4+ cells, and CD8+ cells in grafts. In univariate analysis of the total cohort, age ≥60 years, receiving ASCT at complete remission (CR), higher number of mononuclear cell (MNC), CD3+ cell counts, CD4+ cells as well as CD8+ cells transfused and plerixafor-based mobilization were associated with ES after ASCT. Multivariate analysis showed that age ≥60 years (P = .0014), receiving ASCT at CR (P = .002), and higher number of MNC transfused (P = .026) were associated with ES in total cohort. In plasma cell disease subgroup, age ≥60 years (P = .013), plerixafor-based mobilization (P = .036), and receiving ASCT at CR (P = .002) were associated with ES. Patients with more risk factors had a higher risk of ES. The 1-year probabilities of relapse, non-relapse mortality, and survival were comparable between patients with and without ES. Thus, plerixafor-based mobilization may influence the composition of T lymphocytes in grafts and increase the risk of ES, particularly in patients with plasma cell disease.

The effect of mobilizing large numbers of CD34 + cells (super-mobilizers) on the engraftment and survival in patients undergoing autologous stem cell transplantation

With the use of plerixafor in addition to growth factor for peripheral blood stem cell mobilization, the yield of autologous stem cell harvest has been higher while the length of apheresis days has become shorter. There is still debate whether higher cell collection efficacy in autologous stem cell transplant (ASCT) affect outcomes. In this retrospective study, we defined two groups of patients, group 1, super-mobilizers, with more than double the target cell dose collected (n = 15), while group 2 included all other patients (n = 75). Multiple myeloma (MM) and lymphoma patients were combined. Patients with chemo-mobilization, those needed more than one day apheresis, or with less than 100 days after ASCT were excluded. Correlations were performed between cell collection efficacy and post thaw CD34 cell viability (by 7AAD flow cytometry method), product HCT, and engraftment of neutrophils and platelets. We performed multiple linear regression using the above variables in addition to age, sex and disease type. We used Kaplan Meier's curves to show effect of cell collection efficacy on 1-year overall survival (OS). Our results show that all super-mobilizers received plerixafor in addition to G-CSF, while 83% did in group 2. Correlations between cell collection efficacy and neutrophil and platelet engraftment in group 1 and 2 was modest and better in group 1 (R=0.449 Vs 0.233 for neutrophils; R=0.464 Vs 0.110 for platelets, respectively). However, multiple linear regression showed statistically significant association between cell collection, as a continuous variable, with disease type (P < 0.001), product HCT (P < 0.001), post thaw viability (P = 0.003), and age (P = 0.013). MM patients were more likely to be super-mobilizers, while the product HCT was higher in the super-mobilizers. No significant effect of cell collection efficacy was found on engraftment of neutrophils or platelets. With relatively short post ASCT follow up, 6 patients in group 2 died of any cause while no deaths were recorded in the super-mobilizers group (P = 0.1892 by log-rank test). In conclusion, stem cell collection efficacy in ASCT is more frequent in MM than lymphoma patients, but is not predictive of faster engraftment. On the other hand, 1-year OS was 100% in the super-mobilizers group versus 93% in the other group.

Effect of transplanted cells with CD184 and CD26 expressions and reconstitution of CD3+ lymphocyte population on long-term survival after autologous hematopoietic stem cell transplantation for multiple myeloma

Autologous hematopoietic stem cell transplantation (auto-SCT) is the recommended treatment for responding patients with multiple myeloma (MM). However, we do not know the risk factors influencing long-term survival without progression after auto-SCT. Therefore, this prospective study aimed to investigate the influence of transplanted cells with cluster of differentiation (CD)184+ expression, CD26+ lymphocytes and monocytes, and reconstitution of CD3+ lymphocytes on overall survival (OS) and progression-free survival (PFS) after auto-SCT in MM. Forty-eight patients with MM underwent auto-SCT at our center from 2011 to 2013. The numbers of CD184+ cells, CD26+ lymphocytes, and CD26+ monocytes were measured in the harvested material. In addition, the number of lymphocyte subpopulations (CD3+ lymphocytes, helpers, suppressors, natural killer (NK), cytotoxic NK, and B lymphocytes) was measured in peripheral blood during regeneration after auto-SCT. Flow cytometry was performed in both cases. The median OS was 92 months. Our analysis revealed a statistically significant effect of the number of transplanted CD184+ cells on OS and a statistically significant correlation between PFS and the number of transplanted CD184+ cells and reconstitution of CD3+ lymphocytes. In conclusion, our study showed that the increasing numbers of transplanted CD184+ cells, CD26+ lymphocytes, and CD26+ monocytes augmented the risk of death.

A prognostic model incorporating inflammatory cells and cytokines for newly diagnosed multiple myeloma patients

Peripheral blood cell counts and cytokines can be used as predictors of multiple myeloma (MM) patients' outcomes. 313 newly diagnosed MM patients treated with novel agents were divided into training and validation cohorts. We selected the common peripheral blood cell counts, including the lymphocyte/monocyte ratio (LMR), neutrophil/lymphocyte ratio (NLR), and platelet/lymphocyte ratio (PLR), systemic inflammation response index (SIRI), and serum cytokines which contained tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-2 receptor (IL-2R), interleukin-8 (IL-8), interleukin-6 (IL-6), and interleukin-10 (IL-10) as related variables. The least absolute shrinkage and selection operator (LASSO) regression was conducted to sort the predictor variables in the training cohort, and then the developed nomogram was assessed in the training and validation cohort. Our study showed that SIRI, PLR, and IL-8 were independent prognostic factors for the survival of MM patients. Patients with lower SIRI (≤ 0.87) had superior survival than patients with higher SIRI (> 0.87). Further, according to the LASSO regression, a nomogram embracing LMR (> 3.78), SIRI (> 0.87), PLR (≤ 106.44), and IL-8 was established. The nomogram demonstrated a better correlation with the outcomes of MM patients in the training cohort than International Staging System (ISS) and Revised-International Staging System (R-ISS). The same results were verified in the validation cohort. The nomogram incorporating inflammatory cells and cytokines could be a helpful tool to stratify MM patients in the era of novel agents.

Expansion of large granular lymphocytes after autologous hematopoietic stem cell transplantation

Expansion of large granular lymphocytes (LGLs) is sometimes observed in allogeneic hematopoietic stem cell transplantation (HSCT) recipients, and is reported to be associated with a favorable transplant outcome. LGLs are also observed after autologous HSCT, but their clinical implications have not been well investigated. We retrospectively reviewed peripheral blood smears of consecutive autologous HSCT recipients. LGL lymphocytosis was defined as the observation of LGLs in the peripheral blood (> 20% white blood cells) in at least two consecutive blood tests. We evaluated the clinical impact of LGL lymphocytosis on autologous HSCT recipients. LGL lymphocytosis was observed in 18 of 197 patients (9.1%) who received autologous HSCT, at a median of 49 days after transplantation, with a median duration of 120.5 days. Incidence of cytomegalovirus reactivation was significantly higher in patients with LGL lymphocytosis than those without (16.7% vs. 3.3%, p = 0.038). No significant difference in survival rates was observed between groups (3 year OS 90.9% vs. 90.5%, p = 0.793 for lymphoma; 100 vs. 92.4%, p = 0.328 for myeloma). LGL lymphocytosis was observed in almost 10% of autologous HSCT recipients. In contrast to allogeneic HSCT, the duration of LGL was shorter and no significant improvement in survival was observed.

Natural Killer Cells Are Key Host Immune Effector Cells Affecting Survival in Autologous Peripheral Blood Hematopoietic Stem Cell Transplantation

The infusion of autograft immune effector cells directly impacts the clinical outcomes of patients treated with autologous peripheral blood hematopoietic stem cell transplantation, suggesting the possibility of an autologous graft-versus tumor cells. Furthermore, the early recovery of immune effector cells also affects survival post-autologous peripheral blood hematopoietic stem cell transplantation. Natural killer cells are among the immune effector cells reported to be collected, infused, and recovered early post-autologous peripheral blood hematopoietic stem cell transplantation. In this review, I attempt to give an update on the role of natural killer cells regarding improving survival outcomes on patients treated with autologous peripheral blood hematopoietic stem cell transplantation.

Epidemiology of early infections and predictors of mortality after autologous hematopoietic stem-cell transplantation among multiple myeloma, Hodgkin, and non-Hodgkin lymphoma: the first experience from Palestine

Background

Autologous hematopoietic stem-cell transplantation (HSCT) is the standard of care in many relapsed and refractory lymphoid malignancy, neuroblastoma, and multiple myeloma (MM). This study was conducted to describe the epidemiology of early infections that occurred within the first 100 days among patients who received HSCT for MM, Hodgkin (HL), and non-Hodgkin lymphoma (NHL) in Palestine.

Methods

This study was conducted in a retrospective cohort design in the only autologous HSCT in Palestine in the period between 2014 and 2021. The medical records of the patients were reviewed to identify and collect demographic, clinical, and microbiological data on bacterial, viral, fungal, and parasitic infections as diagnosed by cultures, polymerase chain reaction, and fluorescent antibody testing.

Results

A total of 145 patients were included in this study (median age = 44.0 [28.0, 53.5] years). Of those, 8 (5.5%) were younger than 18 years, 69 (47.6%) had MM, 53 (36.6%) had HL, and 23 (15.9%) had NHL. The source of fever had no focus in the majority of the cases 82 (56.6%), 12 (8.3%) had bloodstream infections, 8 (5.5%) had colitis, and 7.6 (5.0%) had pneumonia. Patients from whom gram-negative bacteria were isolated stayed in the hospital for longer duration compared to the other patients (median = 21.0 [19.0, 25.0] vs. 18.0 [15.0, 22.0] days, p-value = 0.043, respectively). The cumulative incidence of death in the first 100 days after infusion of stem cells was 3.4%. The cumulative incidence of death in the first 100 days post-transplantation was higher for patients with NHL compared to those with HL and MM (p-value = 0.017). Gram-negative and fungal infections were strong predictors of mortality.

Conclusion

Bacterial gram-positive and gram-negative infections were the most common early infections among patients who underwent autologous HSCT for hematological malignancies (HM) in the only center in Palestine. The findings of this study are informative to healthcare providers and planners of care for patients who are scheduled to receive autologous HSCT for HM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07709-4.

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.

Prognostic impact of natural killer cell recovery on minimal residual disease after autologous stem cell transplantation in multiple myeloma

INTRODUCTION

Natural killer cells are a potent effector lymphocyte subset that can induce cytotoxicity without the need for antigen sensitization or presentation. NK cells are a tempting target -for immune therapy, monoclonal antibody, or genetic engineering-to enhance immune surveillance mechanisms against myeloma cells.

MATERIALS AND METHODS

We hypothesized an association between natural killer cell recovery after autologous stem cell transplantation (ASCT) and disease outcomes in multiple myeloma patients. We concluded a prospective study that started enrolling patients in January 2020 to identify the association between absolute NK cell count two to three after ASCT and disease outcomes after autologous stem cell transplantation in multiple myeloma using univariate and multivariate analysis.

RESULTS

Natural killer cell recovery was evaluated during the third month after ASCT, day +60 to +90 post-ASCT. Our patients had a mean NK cell count of 90.53, ranging from 14 to 282 Cell/μL (Std Dev 84.64 Cell/μL). The odds of having a minimal residual disease (MRD-positivity) among patients with partial remission before transplantation is four times higher than patients with very good partial response or better (95% confidence interval 0.45-35.79). Our patients were classified into two groups based on MRD status after ASCT, an MRD-negative group of eight participants and an MRD-positive group of seven participants. The mean absolute NK cell count was significantly higher in the MRD-negative cohort, 131.38 Cell/μL, versus 43.86 Cell/μL in the MRD-positive group (p = 0.049).

CONCLUSION

We conclude that for multiple myeloma patients treated with ASCT, high absolute NK cell counts two to three months after ASCT is an independent predictor for MRD negativity.

Prognostic Nutritional Index Predicts Early Mortality in Diffuse Large B-cell Lymphoma

Objective:

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Blood Graft and Outcome After Autologous Stem Cell Transplantation in Patients With Primary Central Nervous System Lymphoma

Background

Autologous stem cell transplantation (auto-SCT) is a treatment option for patients with primary central nervous system lymphoma (PCNSL).

Methods

In this prospective multicenter study, the effects of blood graft cellular content on hematologic recovery and outcome were analyzed in 17 PCNSL patients receiving auto-SCT upfront.

Results

The infused viable CD34⁺ cell count > 1.7 × 10⁶/kg correlated with more rapid platelet engraftment (10 vs. 31 days, P = 0.027) and with early neutrophil recovery (day + 15) (5.4 vs. 1.6 × 10⁹/L, P = 0.047). A higher number of total collected CD34⁺ cells > 3.3 × 10⁶/kg infused predicted worse 5-year progression-free survival (PFS) (33% vs. 100%, P = 0.028). In addition, CD3⁺CD8⁺ T cells > 78 × 10⁶/kg in the infused graft impacted negatively on the 5-year PFS (0% vs. 88%, P = 0.016).

Conclusion

The cellular composition of infused graft seems to impact on the hematologic recovery and PFS post-transplant. Further studies are needed to verify the optimal autograft cellular content in PCNSL.

Immune Reconstitution following High-Dose Chemotherapy and Autologous Stem Cell Transplantation with or without Pembrolizumab Maintenance Therapy in Patients with Lymphoma

Autologous stem cell transplantation (ASCT) is a standard of care for patients with chemosensitive, relapsed/refractory (R/R) classical Hodgkin lymphoma (cHL) and diffuse large B cell lymphoma (DLBCL). Whereas the clinical benefit of ASCT has traditionally been attributed solely to cytoreduction from intensive chemotherapy, ASCT has important immunogenic effects that may contribute to its antitumor efficacy and could provide a favorable immune environment for post-ASCT immune-based maintenance treatments. We previously reported clinical results of a phase II trial (ClinicalTrials.gov identifier NCT02362997) testing 8 doses of pembrolizumab maintenance therapy after ASCT for patients with R/R cHL or DLBCL. To clarify the impact of pembrolizumab on immune reconstitution, we compared the kinetics of peripheral blood immune cell recovery after ASCT for trial patients receiving pembrolizumab maintenance to those of a contemporaneous control cohort of similar patients undergoing ASCT without pembrolizumab maintenance. This study was conducted to characterize the impact of post-ASCT pembrolizumab maintenance therapy on immune reconstitution for patients with R/R DLBCL and cHL and to identify candidate biomarkers of efficacy and immune-related adverse events (irAEs). Peripheral blood (PB) mononuclear cell samples were prospectively collected at 1 to 18 months after ASCT and analyzed by flow cytometry using a panel of fluorophore-conjugated monoclonal antibodies to identify B cells, natural killer (NK) cells, and various dendritic cell (DC) and T cell subsets. A median of 5 (range, 1 to 8) post-ASCT PB samples were collected from 144 patients (59 in the pembrolizumab group and 85 in the control group). Clinical characteristics of the 2 cohorts were similar. Compared with cHL patients, DLBCL patients (all of whom received anti-CD20 monoclonal antibody therapy before ASCT) had delayed CD19⁺ cell reconstitution that persisted for at least 18 months after ASCT. No other differences in immune reconstitution based on lymphoma subtype were observed. Post-ASCT pembrolizumab maintenance therapy was associated with an elevation in circulating DCs (driven by higher levels of plasmacytoid and immature DCs) that persisted for the duration of pembrolizumab treatment, along with a significant reduction in PD-1⁺ T cells that persisted for 6 to 12 months after completion of pembrolizumab therapy. Despite the key role of T cells in mediating the effects of PD-1 blockade, pembrolizumab maintenance did not affect recovery of any T cell subsets. In an exploratory analysis, a higher baseline CD4⁺ terminal effector memory cell count (defined as CD3⁺CD4⁺CD45RA⁺CD62L^-) was associated with inferior progression-free survival (PFS), but only among patients who received pembrolizumab maintenance (P = .003). As continuous variables, lower absolute levels of NK cells (P = .009), PD-1⁺ CD4⁺ T cells (P = .005), and PD-1⁺ CD8⁺ T cells (P = .005) before pembrolizumab initiation were each associated with a higher risk of grade 2+ irAEs. Our findings indicate that post-ACST pembrolizumab maintenance therapy is associated with a persistent elevation of circulating DCs, but its impact on the reconstitution of other immune cells in peripheral blood appears limited. Our study suggests that early features of post-ASCT immune reconstitution could be associated with PFS and the risk of irAE and warrant additional investigation. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

A Retrospective Analysis: Autologous Peripheral Blood Hematopoietic Stem Cell Transplant Combined With Adoptive T-Cell Therapy for the Treatment of High-Grade B-Cell Lymphoma in Ten Dogs

In humans, a type of cellular immunotherapy, called adoptive T cell transfer (ACT), can elicit curative responses against hematological malignancies and melanoma. ACT using ex vivo expanded peripheral blood T-cells after multiagent chemotherapy enhances tumor-free survival of dogs with B-cell lymphoma (LSA). Since 2008, our group has been performing autologous peripheral blood hematopoietic stem cell transplants (autoPBHSCT) for the treatment of canine high-grade B-cell LSA, although relapse of residual disease is a common cause of reduced survival in ~70% of treated dogs. We reasoned that a more aggressive treatment protocol combining CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy, autoPBHSCT, and ACT to treat 10 dogs with B-cell LSA could lead to better outcomes when compared to dogs treated with CHOP chemotherapy and autoPBHSCT alone. Using this protocol, once dogs achieved complete hematologic reconstitution post-autoPBHSCT, CD3+ CD8+ and CD3+CD4+ T-cells were expanded from the peripheral blood at a commercial laboratory. Two to four ACT infusions were given to each dog, with a total of 23 infusions given. Infusions were administered with no complications or adverse events. The median cell dose for all infusions was 5.62 x 10⁶ cells/kg (range: 2.59 x 10⁶-8.55 x 10⁶ cells/kg). 4/10 (40%) of dogs were cured of their disease (defined as disease-free for ≥2 years post-autoPBHSCT). Our results confirm that the autoPBHSCT protocol did not hinder the in vitro expansion of autologous peripheral blood T-cells and that the final product could be administered safely, with no adverse events recorded. Finally, since only ten dogs were treated, our results can only suggest that the administration of ACT to dogs after multiagent chemotherapy and autoPHSCT did not lead to a statistically significant increase in median disease-free interval and overall survival when compared to dogs who received CHOP chemotherapy and autoPHSCT alone.

NK Cell Reconstitution After Autologous Hematopoietic Stem Cell Transplantation: Association Between NK Cell Maturation Stage and Outcome in Multiple Myeloma

Autologous hematopoietic stem cell transplantation (autoHSCT) is a standard of care for transplant-eligible patients with multiple myeloma (MM). Among factors that influence outcome after autoHSCT, it has been suggested that the number of natural killer (NK) cells plays an important role. However, the impact that different NK cell subsets and their phenotype could have in disease progression after autoHSCT are less clear. For this reason, we have phenotypically and functionally characterized NK cells during immune system reconstitution after autoHSCT in 54 MM patients. Shortly after leukocyte recovery, an extensive redistribution of NK cell subsets occurs in these patients. In addition, NK cells undergo a profound phenotypic change characterized, among others, by their increased proliferative capacity and immature phenotype. Importantly, MM patients who showed lower frequencies of the mature highly differentiated NKG2A-CD57+ NK cell subset at +30 and +100 days after autoHSCT experienced superior progression-free survival and had a longer time to the next treatment than those with higher frequencies. Our results provide significant insights into NK cell reconstitution after autoHSCT and suggest that the degree of NK cell maturation after autoHSCT affects the clinical outcome of MM patients treated with this therapeutic strategy.

CD4+ T Cell Dependent B Cell Recovery and Function After Autologous Hematopoietic Stem Cell Transplantation

Introduction

High-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (auto-HSCT) represents a standard treatment regime for multiple myeloma (MM) patients. Common and potentially fatal side effects after auto-HSCT are infections due to a severely compromised immune system with hampered humoral and cellular immunity. This study delineates in depth the quantitative and functional B cell defects and investigates underlying extrinsic or intrinsic drivers.

Methods

Peripheral blood of MM patients undergoing high-dose chemotherapy and auto-HSCT (before high-dose chemotherapy and in early reconstitution after HSCT) was studied. Absolute numbers and distribution of B cell subsets were analyzed ex vivo using flow cytometry. Additionally, B cell function was assessed with T cell dependent (TD) and T cell independent (TI) stimulation assays, analyzing proliferation and differentiation of B cells by flow cytometry and numbers of immunoglobulin secreting cells in ELISpots.

Results

Quantitative B cell defects including a shift in the B cell subset distribution occurred after auto-HSCT. Functionally, these patients showed an impaired TD as well as TI B cell immune response. Individual functional responses correlated with quantitative alterations of CD19+, CD4+, memory B cells and marginal zone-like B cells. The TD B cell function could be partially restored upon stimulation with CD40L/IL-21, successfully inducing B cell proliferation and differentiation into plasmablasts and immunoglobulin secreting cells.

Conclusion

Quantitative and functional B cell defects contribute to the compromised immune defense in MM patients undergoing auto-HSCT. Functional recovery upon TD stimulation and correlation with CD4+ T cell numbers, indicate these as extrinsic drivers of the functional B cell defect. Observed correlations of CD4+, CD19+, memory B and MZ-like B cell numbers with the B cell function suggest that these markers should be tested as potential biomarkers in prospective studies.

Novel Cell and Immune Engagers in Optimizing Tumor- Specific Immunity Post-Autologous Transplantation in Multiple Myeloma

Autologous stem cell transplantation (ASCT) is an important component of treatment of multiple myeloma (MM). The post-ASCT setting offers a unique opportunity to increase myeloma specific immunity through enhancement of T and NK cell responses. The vast array of therapeutics being developed for MM, including cell-based therapies, dendritic vaccines, bispecific antibodies, and IL-15 agonists, provide the opportunity to increase tumor-specific immunity. Maintenance therapies, including immunomodulatory drugs, proteasome inhibitors, and daratumumab, exhibit a significant anti-myeloma response by modulating the immune system. Lenalidomide promotes an antitumoral immune microenvironment, whereas daratumumab can potentially cause NK cell fratricide. Thus, understanding the effects of commonly used maintenance drugs on the immune system is important. In this review, we look at current and emerging therapeutics and their integration post-ASCT in the context of immune reconstitution to improve clinical responses in patients with MM. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

The association of mobilising regimen on immune reconstitution and survival in myeloma patients treated with bortezomib, cyclophosphamide and dexamethasone induction followed by a melphalan autograft

G-CSF only mobilisation has been shown to enhance immune reconstitution early post-transplant, but its impact on survival remains uncertain. We undertook a retrospective review of 12 transplant centres to examine overall survival (OS) and time to next treatment (TTNT) following melphalan autograft according to mobilisation method (G-CSF only vs. G-CSF and cyclophosphamide [CY]) in myeloma patients uniformly treated with bortezomib, cyclophosphamide and dexamethasone induction. Six centres had a policy to use G-CSF alone and six to use G-CSF + CY. Patients failing G-CSF only mobilisation were excluded. 601 patients were included: 328: G-CSF + CY, 273: G-CSF only. Mobilisation arms were comparable in terms of age, Revised International Staging System (R-ISS) groups and post-transplant maintenance therapy. G-CSF + CY mobilisation generated higher median CD34 + yields (8.6 vs. 5.5 × 10⁶/kg, p < 0.001). G-CSF only mobilisation was associated with a significantly higher lymphocyte count at day 15 post-infusion (p < 0.001). G-CSF only mobilisation was associated with significantly improved OS (aHR = 0.60, 95%CI 0.39-0.92, p = 0.018) and TTNT (aHR = 0.77, 95%CI 0.60-0.97, p = 0.027), when adjusting for R-ISS, disease-response pre-transplant, age and post-transplant maintenance therapy. This survival benefit may reflect selection bias in excluding patients with unsuccessful G-CSF only mobilisation or may be due to enhanced autograft immune cell content and improved early immune reconstitution.

Long-acting granulocyte colony-stimulating factor pegfilgrastim (lipegfilgrastim) for stem cell mobilization in multiple myeloma patients undergoing autologous stem cell transplantation

Autologous stem cell transplantation (ASCT) is a standard of care in newly-diagnosed multiple myeloma (MM) patients. Several studies before the introduction of novel therapies in MM, demonstrated a pegylated G-CSF to be successful in mobilizing peripheral blood stem cells (PBSCs). Lipegfilgrastim is a novel long-acting G-CSF that is produced by the conjugation of a single 20-kDa polyethelene glycol to the natural O-glycosylation site of G-CSF. Twenty-four MM patients were included for PBSCs mobilization with a single SC injection of 6 mg lipegfilgrastim. PBSC collection was started when the CD34⁺ count was > 10 × 10⁶ cells/L. The target progenitor cells were 6 × 10⁶ cells/kg. The median day of apheresis was + 3 (range 2-5) following lipegfilgrastim. Median peripheral blood CD34⁺ count pre-mobilization was of 22.65 (range 3.36-105) × 10⁶ cells/L. The median number of leukaphaeresis procedures was 2 (range 1-4). The median mobilized CD34⁺ cells/kg were 8.26 (range 0.77-12.42). One patient failed to mobilize and two patients mobilized < 6 × 10⁶ cells/kg. Toxicity was mild and transient. Twenty-three patients underwent ASCT following high dose melphalan. All patients engrafted. As lipegfilgrastim is administered only once, it is conceivable that it improves both compliance and quality-of-life (NCT02488382).

Infused Autograft Absolute Lymphocyte Count Predicts Superior Survival in Diffuse Large B Cell Lymphoma Patients Post-Autologous Peripheral Blood Hematopoietic Stem Cell Transplantation: A Matched Case-Control Study

Our group published a double phase III trial showing that patients infused with an autograft absolute lymphocyte count (A-ALC) ≥0.5 × 10⁹ cells/kg experienced superior survival post-autologous peripheral blood hematopoietic stem cell transplantation (APBHSCT). Based on the results from our phase III study, as well as published retrospective studies, on April 1, 2017, our Bone Marrow Transplant Program changed our standard practice to collect an A-ALC ≥0.5 × 10⁹ cells/kg in addition to stem cells for lymphoma patients undergoing APBHSCT. The primary objective of the present study was to continue to assess the prognostic ability of A-ALC by evaluating overall survival (OS) and progression-free survival (PFS) of diffuse large B cell lymphoma (DLBCL) patients who underwent APBHSCT after April 1, 2017, compared with matched control groups at a 1:1:1 ratio with DLBCL patients infused with an A-ALC <0.5 × 10⁹ cells/kg and A-ALC ≥0.5 × 10⁹ cells/kg before April 1, 2017. Using the GREEDY algorithm, 85 DLBCL patients (cases) infused with an A-ALC ≥0.5 × 10⁹ cells/kg after April 1, 2017, were matched at a 1:1:1 ratio with control groups of DLBCL patients who underwent transplantation before April 1, 2017: patients infused with an A-ALC <0.5 × 10⁹ cells/kg (control 1) and patients infused with an A-ALC ≥0.5 × 10⁹ cells/kg (control 2) before April 1, 2017. Groups were matched in terms of sex, age, stage, lactate dehydrogenase (LDH) level, performance status, extranodal disease, International Prognostic Index (IPI), and disease status before APBHSCT (complete or partial response). Survival follow-up was truncated at 3 years from the date of transplantation. Cases, control 1, and control 2 were balanced as to age (P = .8), sex (P = .9), LDH (P = .6), performance status (P = .5), extranodal disease (P = .2), IPI (P = .6), and disease status before APBHSCT (P = .2). Cases and control 2 showed superior OS and PFS compared with control 1. Multivariate analysis including all patients continued to show A-ALC ≥0.5 × 10⁹ cells/kg as an independent predictor for OS (hazard ratio [HR], 0.382; 95% confidence interval [CI], 0.241 to 0.605; P < .0001) and PFS (HR, 0.437; 95% CI, 0.279 to 0.629; P < .0001). Our matched case-control study supports the results of previously published retrospective studies and our phase III study showing that the infusion of A-ALC is a prognostic factor for survival in DLBCL patients undergoing APBHSCT. Our findings support the practice of collecting not only enough stem cells for hematologic engraftment, but also enough immune effector cells (ie, A-ALC) to improve clinical outcomes in DLBCL patients post-APBHSCT.

Autograft cellular composition and outcome in myeloma patients: Results of the prospective multicenter GOA study

BACKGROUND

Autologous stem cell transplantation (auto-SCT) is a widely used treatment option in multiple myeloma (MM) patients. The optimal graft cellular composition is not known.

STUDY DESIGN AND METHODS

Autograft cellular composition was analyzed after freezing by flow cytometry in 127 MM patients participating in a prospective multicenter study. The impact of graft cellular composition on hematologic recovery and outcome after auto-SCT was evaluated.

RESULTS

A higher graft CD34⁺ cell content predicted faster platelet recovery after auto-SCT in both the short and long term. In patients with standard-risk cytogenetics, a higher graft CD34⁺ count (>2.5 × 10⁶ /kg) was linked with shorter progression-free survival (PFS; 28 vs. 46 months, p = 0.04), but there was no difference in overall survival (OS) (p = 0.53). In a multivariate model, a higher graft CD34⁺ CD133⁺ CD38^- (>0.065 × 10⁶ /kg, p = 0.009) and NK cell count (>2.5 × 10⁶ /kg, p = 0.026), lenalidomide maintenance and standard-risk cytogenetics predicted better PFS. In contrast, a higher CD34⁺ count (>2.5 × 10⁶ /kg, p = 0.015) predicted worse PFS. A very low CD3⁺ cell count (≤20 × 10⁶ /kg, p = 0.001) in the infused graft and high-risk cytogenetics remained predictive of worse OS.

CONCLUSIONS

Autograft cellular composition may impact outcome in MM patients after auto-SCT. More studies are needed to define optimal graft composition.

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.

Dynamics of thymus function and T cell receptor repertoire breadth in health and disease

T cell recognition of unknown antigens relies on the tremendous diversity of the T cell receptor (TCR) repertoire; generation of which can only occur in the thymus. TCR repertoire breadth is thus critical for not only coordinating the adaptive response against pathogens but also for mounting a response against malignancies. However, thymic function is exquisitely sensitive to negative stimuli, which can come in the form of acute insult, such as that caused by stress, infection, or common cancer therapies; or chronic damage such as the progressive decline in thymic function with age. Whether it be prolonged T cell deficiency after hematopoietic cell transplantation (HCT) or constriction in the breadth of the peripheral TCR repertoire with age; these insults result in poor adaptive immune responses. In this review, we will discuss the importance of thymic function for generation of the TCR repertoire and how acute and chronic thymic damage influences immune health. We will also discuss methods that are used to measure thymic function in patients and strategies that have been developed to boost thymic function.

Mobilization characteristics, blood graft composition, and outcome in diffuse large B-cell lymphoma after autologous stem cell transplantation: Results from the prospective multicenter GOA study

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is a common indication for autologous stem cell transplantation (auto-SCT).

STUDY DESIGN AND METHODS

This prospective noninterventional study aimed to evaluate the impact of mobilization characteristics and graft cellular content on hematologic recovery and outcome after auto-SCT among 68 patients with DLBCL.

RESULTS

Better mobilization capacity as manifested by blood CD34⁺ cell count >32 × 10⁶ /L and CD34⁺ cell yield of the first apheresis >2.75 × 10⁶ /kg correlated with faster neutrophil (P = .005 and P = .017) and platelet (P = .002 and P < .001) recovery. A higher number of infused CD34⁺ cells (> 2.65 × 10⁶ /kg) was associated with better 5-year overall survival (OS; 95% vs 67%, P = .012). The graft CD34⁺ CD133⁺ CD38^- cell count >0.07 × 10⁶ /kg was predictive of better 5-year OS (87% vs 63%; P = .008) and higher graft CD3⁺ cell count (>23.1 × 10⁶ /kg) correlated also with better 5-year OS (80% vs 40%, P = .008). In multivariate analysis only disease status of CR I at auto-SCT was associated with better progression-free survival (P = .014) and OS (P = .039).

CONCLUSION

The mobilization capacity of CD34⁺ cells impacted on early hematologic recovery in patients with DLBCL after auto-SCT. Higher graft CD34⁺ cell count and both CD34⁺ CD133⁺ CD38^- and CD3⁺ cells were also associated with better OS. The effect of optimal graft cellular composition on outcome in DLBCL should be evaluated in a randomized study.

Continuous lenalidomide and low-dose dexamethasone in patients with transplant-ineligible newly diagnosed MM: FIRST trial subanalysis of Canadian/US patients

The phase 3 FIRST trial demonstrated significant improvement in progression-free survival (PFS) and overall survival (OS) with an immune-stimulatory agent, lenalidomide, in combination with low-dose dexamethasone until disease progression (Rd continuous) vs melphalan +prednisone + thalidomide (MPT) in transplant-ineligible patients with newly diagnosed multiple myeloma (NDMM). Rd continuous similarly extended PFS vs fixed-duration Rd for 18 cycles (Rd18). Outcomes in the Canadian/US subgroup (104 patients per arm) are reported in this analysis. Rd continuous demonstrated a significant improvement in PFS vs MPT (median, 29.3 vs 20.2 months; HR, 0.69 [95% CI, 0.49-0.97]; p = 0.03326) and an improvement vs Rd18 (median, 21.9 months). Median OS was 56.9 vs 46.8 months with Rd continuous vs MPT (p = 0.15346) and 59.5 months with Rd18. The overall response rate was higher with Rd continuous and Rd18 (78.8% and 79.8%) vs MPT (65.4%). In the 49.0%, 52.9%, and 29.8% of patients with at least very good partial response in the Rd continuous, Rd18, and MPT arms, respectively, the median PFS was 56.0, 30.9, and 40.2 months, respectively. The most common grade 3/4 treatment-emergent adverse events were neutropenia (28.4%, 30.1%, and 52.0%), anemia (23.5%, 21.4%, and 23.5%), and infections (37.3%, 30.1%, and 24.5%) with Rd continuous, Rd18, and MPT, respectively. These results were consistent with those in the intent-to-treat population, confirming the benefit of Rd continuous vs MPT in the Canadian/US subgroup and supporting the role of Rd continuous as a standard of care for transplant-ineligible patients with NDMM.

Progressive multifocal leukoencephalopathy (PML) following autologous peripheral blood stem cell transplantation for multiple myeloma

PML should be considered in patients with neurological symptoms following MM and in those who are immunosuppressed. Symptoms are diverse and often rapidly progressing. Prompt referral and early involvement of the multidisciplinary team are crucial.

Prognostic Significance of Absolute Lymphocyte Count, Absolute Monocyte Count, and Absolute Lymphocyte Count to Absolute Monocyte Count Ratio in Follicular Non-Hodgkin Lymphoma

INTRODUCTION

Recently, the lymphocyte to monocyte ratio (LMR) has been proposed as an easily determinable prognostic factor in patients with cancer, including lymphomas. The objective of this study was the evaluation of the impact of baseline absolute lymphocyte count (ALC), absolute monocyte count (AMC), and the LMR on the treatment response and prognosis in follicular lymphoma (FL).

PATIENTS AND METHODS

The data of 100 patients with a FL variant, admitted and treated between January 2009 and June 2018, were analyzed.

RESULTS

The area under the receiver operator characteristic curve and cutoff values of ALC, AMC, and LMR for discrimination between survival times using receiver operating characteristic curves showed 0.57 × 10⁹/L as the most discriminative ALC cutoff value, 1.235 ×10⁹/L as the most discriminative AMC cutoff value, and 1.63 as the most discriminative LMR cutoff value. Progressive disease and stable disease after first-line therapy and mortality rate were significantly associated with lower ALC, higher AMC, and higher LMR. Shorter overall survival (OS) was significantly associated with patients with lower ALC when compared with those having higher ALC. Shorter OS and progression-free survival (PFS) were significantly associated with higher AMC when compared with those having lower AMC. Shorter OS and PFS were significantly associated with lower LMR when compared with those having higher LMR. High-risk Follicular Lymphoma International Prognostic Index as well as low LMR were considered as risk factors for prediction of OS in all the studied patients with FL in univariate analysis and multivariate analysis.

CONCLUSION

ALC, AMC, and LMR at diagnosis are simple indices, which reflect the host systemic immunity and can predict the clinical outcomes in FL.

Clinical outcomes of multiple myeloma patients who undergo autologous hematopoietic stem cell transplant with G-CSF or G-CSF and plerixafor mobilized grafts

Impact of Plerixafor (P) mobilized stem cells on immune reconstitution, such as absolute lymphocyte count at day 30 (ALC30), and on long-term outcomes of Multiple Myeloma (MM) patients undergoing autologous stem cell transplant (ASCT) has not been well established. We evaluated total of 469 patients mobilized with G-CSF (G) alone, and 141 patients mobilized with G-CSF plus plerixafor (G+ P). Patients only received plerixafor if they had peripheral blood CD34⁺   blood count <20/μL on first planned day of collection. Primary endpoint, ALC30, was 1.3 K/μL (range, 0.1-4.5) and 1.2 K/μL (range, 0.1-5.1) for G and G + P, respectively (P =. 61). The median PFS was 2.5 years (95% CI, 2.1-3.2) and 2.8 years (95% CI, 2.0-3.3) for G and G + P, respectively (HR: 1.13; 95% CI, 0.84-1.50; P = .42). The median OS was 6.1 years (95% CI, 4.6-NR) for G group compared to 3.7 years (95% CI, 3.2-NR) for the G + P group (HR: 1.64; 95% CI, 1.12-2.40; P = .01). The median follow-up time for OS was 2.53 years (95% CI, 2.13-2.99) and 1.59 years (95% CI, 1.17-2.02) for G and G+ P group, respectively. In this large retrospective analysis of MM patients mobilized with G-CSF vs G-CSF + P, there was no significant difference in lymphocyte recovery or PFS. There was an overall survival difference in patients who were poor mobilizers and could not be mobilized with G-CSF alone.

Inferior prognosis in poor mobilizing myeloma patients

INTRODUCTION

Induction treatment followed by autologous stem cell transplantation (ASCT) has been accepted as the standard treatment for multiple myeloma (MM) patients. Granulocyte colony stimulating agent (G-CSF), chemotherapy or agents likes plerixafor are being used for the mobilization of stem cells from bone marrow. In this study, we evaluated the impact of the mobilization methods on the outcome of MM patients after ASCT.

METHOD

The data of 205 MM patients who underwent ASCT at our center between December 2009 and January 2019 were retrospectively analyzed. Patients were divided into 2 groups as good mobilizers (patients who were mobilized with G-CSF alone) and poor mobilizers (patients who were failed to mobilize with G-CSF alone and mobilized with G-CSF + cylophosphomide or G-CSF + plerixafor).

RESULTS

The median progression free survival (PFS) was 18.27 ± 3.22 months in good mobilizers and 14.22 ± 3.7 months in poor mobilizers. In G-CSF + cyclophosphamide method median PFS was 15.4 ± 4.9 months wheras it was only 4 months in G-CSF + plerixafor method. We did not find a statistically significant difference between good and poor mobilizers regarding median PFS (p: 0.342). The median overall survival (OS) was found 34.48 ± 4.2 months in good mobilizers and 15.13 ± 5.78 months in poor mobilizers. In G-CSF + cyclophosphamide method median OS was 17 ± 14.01 months wheras it was 10.66 ± 7.68 months in G-CSF + plerixafor method. We found a statistically significant difference between good and poor mobilizers regarding median OS (p: 0.007*).

CONCLUSION

Our study shows that difficulty in stem cell mobilization is correlated with worse outcome.

Oral calcitriol in hematopoietic recovery and survival after autologous stem cell transplantation: a randomized clinical trial

BACKGROUND

Calcitriol, the active metabolite of vitamin D, is an essential regulator in the hematopoiesis and immunity. However, knowledge revealing its influence on the immune and hematologic reconstitution after hematopoietic stem cell transplantation (HSCT) in clinical trials is very limited.

OBJECTIVES

The effects of calcitriol on short-term and long-term hematopoietic recovery, relapse-free survival (RFS) and overall survival (OS) in multiple myeloma, Hodgkin's and non-Hodgkin's lymphoma following autologous peripheral blood HSCT were assessed.

METHODS

Eighty patients (age: 18-68 years) in complete remission were allocated 1:1 to two groups by balanced block randomization. Calcitriol 0.25 μg or placebo capsule was administered three times daily from transplantation to day 30. Absolute neutrophil count (ANC), absolute lymphocyte count (ALC), and platelet count (PC) were determined daily from transplantation to day 30. White blood cell count (WBC), PC, and hemoglobin concentration (HC) of days 180 and 365 were extracted from clinic files. A thorough examination for oral mucositis (OM) was completed daily during hospital stay. Adverse drug reactions (ADRs) as well as two-year RFS and OS were evaluated.

RESULTS

Median time to ANC engraftment (≥0.5 × 103/μl: 10.0 vs. 11.0 days; P = 0.98) and PC engraftment (≥20.0 × 103/μl: both 14.0 days; P = 0.58) was similar between groups. However, the median time to ALC recovery was significantly shorter in the calcitriol group (≥0.5 × 103/μl: 13.0 vs. 20.0 days; P < 0.001). Moreover, ALC recovery rates on day 15 (≥0.5 × 103/μl: 82.1% vs. 42.5%; P < 0.001) and on day 30 (≥1.0 × 103/μl: 91.7% vs. 57.5%; P = 0.001) was significantly higher with calcitriol. WBC, PC, and HC on days 180 and 365 were not significantly different between groups. None of the OM indices were modulated by calcitriol. All the ADRs were non-serious and mild, possibly or unlikely related to the intervention. In a median of 29 months follow-up, RFS was significantly better in the calcitriol group (77.0%, SE = 7.0% vs. 59.0%, SE = 8.0%; P = 0.03), albeit the OS was not affected (87.0%, SE = 5.0% vs. 92.0%, SE = 4.0%; P = 0.72).

CONCLUSION

Calcitriol could improve ALC recovery and RFS as a safe option post-HSCT. Graphical abstract Oral calcitriol 0.25 µg three times daily from transplantation to day 30 improved lymphocytes recovery and two-year relapse-free survival as a safe option in 80 patients of autologous hematopoietic stem cell transplantation in comparison with placebo.

Circulating monocyte subsets in multiple myeloma patients receiving autologous stem cell transplantation - a study of the preconditioning status and the course until posttransplant reconstitution for a consecutive group of patients

BACKGROUND

Induction therapy of multiple myeloma patients prior to autologous stem cell transplantation has changed from conventional chemotherapy to treatment based on proteasome inhibitors or immunomodulatory drugs. We used flow cytometry to analyze total monocyte and monocyte subset (classical, intermediate and non-classical monocytes) peripheral blood levels before and following auto-transplantation for a consecutive group of myeloma patients who had received the presently used induction therapy.

RESULTS

The patients showed normal total monocyte concentrations after induction/stem cell mobilization, but the concentrations of classical monocytes were increased compared with healthy controls. Melphalan conditioning reduced the levels of total CD14⁺ as well as classical and non-classical monocytes, whereas intermediate monocytes were not affected. Thus, melphalan has a non-random effect on monocyte subsets. Melphalan had a stronger effect on total and classical monocyte concentrations for those patients who had received induction therapy including immunomodulatory drugs. Total monocytes and monocyte subset concentrations decreased during the period of pancytopenia, but monocyte reconstitution occurred before hematopoietic reconstitution. However, the fractions of various monocyte subsets varied considerably between patients.

CONCLUSIONS

The total level of circulating monocytes is normalized early after auto-transplantation for multiple myeloma, but pre- and post-transplant levels of various monocyte subsets show considerable variation between patients.

Post-treatment improvement of NK cell numbers predicts better survival in myeloma patients treated with thalidomide-based regimens

Multiple myeloma (MM) is a disease characterized by antitumoral immune dysfunction. The objective of the present study was to determine lymphocyte subsets (B, T, NK, NKT, iNKT, dendritic cells, and regulatory T cells) in 68 newly diagnosed patients and 113 healthy donors. Lymphocyte subsets were studied in the same patients 6 months after treatment. Pre-treatment values of CD4+ T cells, NK cells, type 2 dendritic cells, and B cells in MM patients were lower than in healthy donors. Forty patients (59%) received MPT treatment and 28 (41%) thal-dex. Patients with no response to treatment, exhibited a decrease in CD4+ T cells and NK cells, as well as an increase in Treg cell numbers. Median DFS and OS was lower in patients not achieving response, in patients having low numbers of NK cells, and higher values of LDH. The number of CD4 T cells, NK, DC2, and B cells at diagnosis is lower in patients with MM. Non-responder patients had lower CD4 and NK, but higher Treg cell values. Patients in which response is not achieved, and those holding lower values of NK cells and higher levels of LDH, have poor DFS and OS.

Potential of NK cells in multiple Myeloma therapy

Introduction: Despite rapid advances in myeloma treatment with the development of new drugs, curative therapies remain elusive. Relapsed/refractory disease related to progressive dysregulation of immune system and acquired genetic abnormalities continues to be a major obstacle in achieving cure. Immune-based therapy harnessing the host defense mechanism of natural killer (NK) cells is a promising avenue in the treatment of myeloma. Areas covered: Here, we discuss the biology and cytotoxic activity of NK cells and the potential role of these innate immune cells in defense against cancer and specifically multiple myeloma. We also discuss the role of NK cells in the anti-myeloma effects of autologous and allogeneic stem cell transplantation, various novel drugs, and treatment modalities such as chimeric antigen receptor therapy. Immune evasion, either directly or indirectly involving NK cell dysfunction, may be a key and under-recognized mechanism in myeloma progression. We reviewed extensive literature identified using the keywords immunotherapy, natural killer cells, and multiple myeloma. Expert opinion: Novel treatment approaches in myeloma utilizing the immunomodulatory and cytotoxic properties of NK cells to eradicate resistant and quiescent clones could pave the way for potentially curative interventions.

Immune Signatures Associated With Clonal Isotype Switch After Autologous Stem Cell Transplantation for Multiple Myeloma

BACKGROUND

High-dose chemotherapy and autologous stem cell transplantation (ASCT) are integral components of the overall treatment for patients with multiple myeloma (MM) aged ≤ 65 years. The emergence of oligoclonal immunoglobulin bands (ie, immunoglobulins differing from those originally identified at diagnosis [termed clonal isotype switch (CIS)]) has been reported in patients with MM after high-dose chemotherapy followed by autologous stem cell transplantation. However, the clinical relevance and the correlation with immune reconstitution remains unclear.

PATIENTS AND METHODS

Patients with MM who had undergone ASCT from 2007 to 2016 were included in the present study. The percentage of natural killer cells, B-cells, and T-cells was measured using flow cytometry in pre- and post-ASCT bone marrow samples. CIS was defined as the appearance of a new serum monoclonal spike on serum protein electrophoresis and immunofixation that differed from original heavy or light chain detected at diagnosis.

RESULTS

A retrospective analysis of 177 patients with MM who had undergone ASCT detected CIS in 39 (22%). CIS after ASCT correlated with improved progression-free survival (52.2 vs. 36.6 months; P = .21) and overall survival (75.1 vs. 65.4 months; P = .021). Patients with a relapse had an isotype that differed from a CIS, confirming the benign nature of this phenomenon. CIS was also associated with lower CD8 T-cell percentages and a greater CD4/CD8 ratio (2.8 vs. 0.2; P = .001) compared with patients who did not demonstrate a CIS, suggestive of more profound T-cell immune reconstitution in this group.

CONCLUSION

Taken together, our data have demonstrated that a CIS is a benign phenomenon and correlates with a reduced disease burden and enriched immune repertoire beyond the B-cell compartment.

Importance of early immune recovery after autologous hematopoietic cell transplantation in lymphoma patients

Lymphomas constitute the second most common indication for autologous hematopoietic cell transplantation (AHCT). Graft infusion is followed by a rapid hematological recovery and slower immune recovery. The number of natural killer cells and CD3⁺ T lymphocytes achieve normal counts usually within a month, whereas the recovery of CD3⁺CD4⁺ T lymphocytes is much slower. Early immune recovery is usually defined as the absolute lymphocyte count (ALC) ≥0.5 × 10⁹/L, which has been associated with improved progression-free and even overall survival. Several factors have been associated with early immune recovery, including higher infused lymphocyte and CD34⁺ cell doses, both of which are affected by the choice of mobilization. This review summarizes the clinical importance of early immune recovery for long-term success of AHCT in lymphomas. Factors known to affect early immune recovery are discussed and suggestions made how to improve mobilization and collection processes to optimize immune recovery and post-transplant outcomes.

Pegfilgrastim: More Cost Effective and Equally Efficacious Option as Compared to Filgrastim in Autologous Stem Cell Transplant

Use of growth factor after high-dose chemotherapy (HDC) and autologous peripheral blood stem cell (PBSC) support is current standard in reducing days of neutropenia. This retrospective study aims to compare the efficacy of two standard growth factors, pegfilgrastim (PEG) and filgrastim (FIL) after HDC. We collected data on 195 consecutive adult patients who received an autotransplant (myeloma, lymphoma and others) between January 2004 and December 2014 at two tertiary care centres. The primary end point was the duration of neutropenia in terms of days to reach an ANC > 0.5 × 10⁹/L. Filgrastim was given to 110 patients and PEG was given to 85 patients. Time to engraftment, defined as the time to reach an ANC of 0.5 × 10⁹/L on 2 consecutive days after the day of auto-SCT, was 12.6 days with FIL compared with 12.1 days with PEG group (p = 0.126). When comparing the total days of severe neutropenia (WBC < 0.1 × 10⁹/L), there were 5.5 days of severe neutropenia with FIL compared with 5.8 days with PEG group (p = 0.7). The duration of febrile neutropenia was an average of 5.3 days with FIL and 4.6 days with PEG (p = 0.029). The total number of antibiotic days was shorter for the patients who received PEG, being 11.08 days with PEG and 12.1 days with FIL (p = 0.184).The average cost savings per person in terms of number of days of hospitalization and number of days of total parental nutrition was 582 Rs (p = 0.512) and 6003 Rs (p = 0.018) respectively in favour of PEG arm. PEG is similar to FIL in hematological reconstitution, however it is more cost effective alternative after HDC and PBSC.

Peripheral blood biomarkers of early immune reconstitution in newly diagnosed multiple myeloma

Peripheral blood biomarkers of tumor microenvironment and immune surveillance are independent prognostic factors in multiple myeloma. The timing and prognostic impact of immune reconstitution has been studied after autologous hematopoietic stem cell transplantation, less is known about its significance in newly diagnosed multiple myeloma. We studied absolute lymphocyte (ALC) and absolute monocyte (AMC) counts at the time of treatment initiation and 1 month thereafter in 771 newly diagnosed patients. Two hundred and thirty-four patients (31%) had evidence of immune dysregulation at baseline (abnormal biomarkers). Eighty-seven of these patients (37%) recovered normal biomarkers at 1 month (early immune reconstitution). The absence of immune dysregulation at baseline (compared to the presence thereof) was associated with better overall survival (HR 0.77, 95% CI 0.61-0.97, P = 0.025, n = 771). The absence of immune dysregulation at 1 month (compared to the persistence or development thereof) was associated with better overall survival (HR 0.63, 95% CI 0.50-0.80, P < 0.001, n = 771). Early immune reconstitution (compared to the persistence or development of immune dysregulation) was associated with better overall survival (HR 0.62, 95% CI 0.43-0.92, P = 0.016, n = 771). Cytogenetic high-risk disease was negatively, and treatment with immunomodulators positively, associated with early immune reconstitution. The presence or development of immune dysregulation in newly diagnosed multiple myeloma is an independent risk factor. The favorable impact of early immune reconstitution suggests immune dysregulation to be a potentially modifiable risk factor that may be exploited for therapeutic benefit.

Impaired lymphocyte reconstitution after autologous transplant is associated with apoptosis of CD8+ T cells and adverse clinical outcome

We noticed that the lymphocyte counts, after autologous hematopoietic stem cell transplantation, oscillated during the first 4 post-transplant months. Thereafter, the lymphocyte counts stabilized and segregated the patients into two groups, those who normalized their lymphocyte counts and those with prolonged lymphopenia. In both groups, the CD4 counts remained low for at least 6 months. However, in approximately half of the patient, the CD8 counts increased to normal or above normal values. Patients with prolonged lymphopenia had higher rates of lymphocytes' spontaneous apoptosis and the lymphocytes in patients who restored their counts expressed the intracellular CD14-derived MO2 epitope that protects the cells from apoptosis. These findings were translated to longer disease-free survival and overall survival in patients who restored the CD8 counts. Collectively, our data show that post-transplant lymphocytes that express intracellular CD14-MO2 epitope have survival advantage.

Peripheral Blood Lymphocyte-to-Monocyte Ratio as a Useful Prognostic Factor in Newly Diagnosed Multiple Myeloma

The survival of individuals with tumors may be predicted by the peripheral blood lymphocyte-to-monocyte ratio (LMR) upon diagnosis in recent studies. For patients with multiple myeloma (MM) in the era of novel agents, the prognostic significance of LMR remains unclear. In this study, the prognostic impact of LMR is evaluated by 285 patients with MM who are treated with proteasome inhibitor and/or immunomodulatory drug. LMR is a proven predictor of survival using the receiver operating characteristic curve, with 4.2 as the cutoff point. Patients with LMR ≤ 4.2 at diagnosis had poorer overall survival (OS) and progression-free survival (PFS) than those with LMR > 4.2. In addition, multivariate analysis showed that LMR less than 4.2 is an independent predictor for the OS (hazard ratio [HR]: 1.703; 95% confidence interval [CI]: 1.020–2.842; P = 0.042) and PFS (HR: 1.831; 95% CI: 1.098–3.053; P = 0.021). According to the test, the LMR at diagnosis, which functions as a simple index reflecting host systemic immunity, can predict clinical outcomes in patients with MM who are treated with new agents.

The effect of the dexamethasone, cytarabine, and cisplatin (DHAP) regimen on stem cell mobilization and transplant outcomes of patients with non-Hodgkin's lymphoma who are candidates for up-front autologous stem cell transplantation

BACKGROUND/AIMS

Data on dexamethasone, cytarabine, and cisplatin (DHAP) as a mobilization regimen, compared to high-dose cyclophosphamide (HDC), for up-front autologous stem cell transplantation (ASCT) in non-Hodgkin's lymphoma (NHL) is limited.

METHODS

Consecutive patients with aggressive NHL treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or rituximab-CHOP who underwent chemomobilization using HDC or DHAP plus granulocyte-colony stimulating factor (G-CSF) for up-front ASCT were enrolled from three institutions between 2004 and 2014.

RESULTS

Ninety-six patients (57 men) were included. Sixty-five patients (67.7%) received HDC; and 31 (32.3%), DHAP. The total CD34+ cells mobilized were significantly higher in patients receiving DHAP (16.1 vs. 6.1 × 106/kg, p = 0.001). More patients achieved successful mobilization with DHAP (CD34+ cells ≥ 5.0 × 106/kg) compared to HDC (87.1% vs. 61.5%, respectively; p = 0.011), particularly within the first two sessions of apheresis (64.5% vs. 32.3%, respectively; p = 0.003). Mobilization failure rate (CD34+ cells < 2.0 × 106/kg) was significantly higher in patients receiving HDC (20.0% vs. 3.2%, p = 0.032). On multivariate analysis, the DHAP regimen (odds ratio, 4.12; 95% confidence interval, 1.12 to 15.17) was an independent predictor of successful mobilization. During chemomobilization, patients receiving HDC experienced more episodes of febrile neutropenia compared to patients receiving DHAP (32.3% vs. 12.9%, p = 0.043).

CONCLUSION

The DHAP regimen was associated with a significantly higher efficacy for stem cell mobilization and lower frequency of febrile neutropenia. Therefore, DHAP plus G-CSF is an effective for mobilization in patients with aggressive NHL who were candidates for up-front ASCT.

Blood graft composition and post-transplant recovery in myeloma patients mobilized with plerixafor: a prospective multicenter study

The composition of autologous blood grafts after cryopreservation, post-transplant hematological recovery up to 1 year and immune recovery up to 6 months as well as outcome was analyzed in 87 patients with multiple myeloma (MM). The patients receiving added plerixafor due to poor mobilization (11%) were compared to those mobilized with G-CSF or cyclophosphamide (CY) plus G-CSF. The use of plerixafor was found to significantly affect the graft composition as there was a significantly higher proportion of the more primitive CD34⁺ cells, higher number of T and B lymphocytes as well as NK cells in the grafts of patients who received also plerixafor. The hematological recovery after auto-SCT was comparable between the groups. The recovery of CD3⁺CD4⁺ T cells was faster in plerixafor mobilized patients at 1 and 3 months post-transplant. There were no significant differences in progression-free (PFS) or overall survival (OS) according to the plerixafor use.

Can Neutrophil-to-Lymphocyte Ratio, Monocyte-to-Lymphocyte Ratio, and Platelet-to-Lymphocyte Ratio at Day +100 be used as a prognostic marker in Multiple Myeloma patients with autologous transplantation?

BACKGROUND

Recent reports have showed that neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR) are predictors of progression-free survival (PFS) and overall survival (OS) in many types of cancer. This study evaluates the predictive value of NLR, MLR, and PLR for survival in MM patients treated with to ASCT.

METHODS

A set of data consisting of 150 patients who underwent autologous stem cell transplantation (ASCT) for MM was collected retrospectively. The prognostic value of NLR, MLR, and PLR was investigated with Kaplan-Meier method.

RESULTS

The prognostic value of NLR, MLR, and PLR was analyzed by a receiver operating characteristic (ROC) curve established to determine the cutoff. These cutoff values of NLR, PLR, and MLR were found 1.46, 86, and 0.27, respectively, on the 100th day of post-transplantation period. The overall survival (OS) and the post-transplantation OS of the patients with high NLR, MLR, and PLR levels on the 100th day of post-transplantation were shorter than the other group (P = 0.05, P = 0.018 [NLR], P = 0.05, P = 0.002 [MLR], P = 0.000, P = 0.001 [PLR]). The post-transplantation progression-free survival (PFS) of the patients with high NLR, MLR, and PLR levels on the 100th day of post-transplantation was shorter as well (P = 0.036, P = 0.001, P = 0.001, respectively).

CONCLUSION

As increased NLR, MLR, and PLR predicted poor clinical outcome in MM patients with autologous transplantation in this study, they may serve as cost-effective and rapidly available prognostic biomarkers for these patients.

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.