HLA alleles, haplotypes frequencies, and their association with hematological disorders: a report from 1550 families whose patients underwent allogeneic bone marrow transplantation in Egypt.

HLA alleles are representative of ethnicities and may play important roles in predisposition to hematological disorders. We analyzed DNA samples for HLA-A, -B, -C, -DRB1, and -DQB1 loci, from 1550 patients and 4450 potential related donors by PCR-SSO (Polymerase chain reaction sequence-specific oligonucleotides) and estimated allele frequencies in donors and patients from 1550 families who underwent bone marrow transplantation (BMT) in Egypt. We also studied the association between HLA allele frequencies and incidence of acute myeloid leukemia, acute lymphoblastic leukemia, and severe aplastic anemia. The most frequently observed HLA class I alleles were HLA- A*01:01 (16.9%), A*02:01 (16.1%), B*41:01 (8.7%), B*49:01 (7.3%), C*06:02 (25.1%), and C*07:01 (25.1%), and the most frequently observed class II alleles were HLA-DRB1*11:01 (11.8%), DRB1*03:01 (11.6%), DQB1*03:01 (27.5%), and DQB1*05:01 (18.9%). The most frequently observed haplotypes were A*33:01~B*14:02 ~ DRB1*01:02 (2.35%) and A*01:01~B*52:01~DRB1*15:01 (2.11%). HLA-DRB1*07:01 was associated with higher AML odds (OR, 1.26; 95% CI, 1.02-1.55; p = 0.030). Only HLA-B38 antigen showed a trend towards increased odds of ALL (OR, 1.52; 95% CI, 1.00-2.30; p = 0.049) HLA-A*02:01, -B*14:02, and -DRB1*15:01 were associated with higher odds of SAA (A*02:01: OR, 1.35; 95% CI, 1.07-1.70; p = 0.010; B*14:02: OR, 1.43; 95% CI, 1.06-1.93; p = 0.020; DRB1*15:01: OR, 1.32; 95% CI, 1.07-1.64; p = 0.011). This study provides estimates of HLA allele and haplotype frequencies and their association with hematological disorders in an Egyptian population.

Comparison of allo-SCT, auto-SCT and chemotherapy for the treatment of patients with low- or intermediate-risk acute myeloid leukemia: a network meta-analysis.

BACKGROUND: The therapeutic status of allogeneic stem cell transplantation (allo-SCT) as a post-remission treatment for patients with high-risk acute myeloid leukemia (AML) was well-accepted. However, the optimal treatment for patients with low/favorable- or intermediate-risk AML who achieve complete remission has remained controversial. Therefore, we conducted a network meta-analysis to discuss this disputed problem. METHODS: We compared the effects of treatment strategies including allo-SCT, autologous stem cell transplantation (auto-SCT) and consolidation chemotherapy (CT) for patients with low/favorable- or intermediate-risk AML. The pooled HRs and 95% CIs for overall survival and disease-free survival were estimated with Stata12 and R software. Thirty clinical studies with 6682 patients were included in the meta-analysis. RESULTS: The results indicated that the treatment outcome of allo-SCT was the best, followed by auto-SCT, and CT was likely the worst in the total AML patients. In patients with low/favorable-risk AML, the treatment outcome of auto-SCT was likely ranked first, followed by allo-SCT, and CT was the worst. In patients with intermediate-risk AML, the treatment outcome of haploidentical stem cell transplantation (haplo-SCT) was the best, followed by allo-SCT (excluding haplo-SCT), and auto-SCT and CT were the worst. However, the median age of the haplo-SCT group was much younger than that of the control group, which may be one of the reasons for the better prognosis of the haplo-SCT group. CONCLUSIONS: Patients with low/favorable- and intermediate-risk (non-high-risk) AML should prioritize allo-SCT if they are eligible for transplantation, and auto-SCT is optional. However, in the subgroup analysis, auto-SCT was the optimal treatment choice for patients with low/favorable-risk AML, and allo-SCT was the priority selection for patients with intermediate-risk AML, especially young patients. These findings could provide references for clinical practice.

Strategies to reduce relapse risk in patients undergoing allogeneic stem cell transplantation for acute myeloid leukaemia.

Allogeneic stem cell transplantation is a centrally important curative strategy in adults with acute myeloid leukaemia; however, relapse occurs in a significant proportion of patients and remains the leading cause of treatment failure. The prognosis for patients who relapse post-transplant remains poor, and the development of new strategies with the ability to reduce disease recurrence without increasing transplant toxicity remains a priority. In this review, within the context of our understanding of disease biology and the graft-versus-leukaemia (GVL) effect, we will discuss established, evolving and novel approaches for increasing remission rates, decreasing measurable residual disease pretransplant, future methods to augment the GVL effect and the opportunities for post-transplant maintenance. Future progress depends upon the development of innovative trials and networks, which will ensure the rapid assessment of emerging therapies in prospective clinical trials.

Successful management of acute graft-versus-host disease with ibrutinib during cord blood transplantation for germline DDX41-mutated acute myeloid leukemia.

Background: Acute graft-versus-host disease (GVHD) is a major complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT) with significant morbidity and mortality, and efficacy of currently available therapeutics are limited. Acute and chronic GVHD are similar in that both are initiated by antigen presenting cells and activation of alloreactive B-cells and T-cells, subsequently leading to inflammation, tissue damage, and organ failure. One difference is that acute GVHD is mostly attributed to T-cell activation and cytokine release, whereas B-cells are the key players in chronic GVHD. Ibrutinib is an irreversible inhibitor of the Bruton's tyrosine kinase (BTK), which is part of B-cell receptor signaling. Ibrutinib is currently used for treating chronic GVHD, but its efficacy towards acute GVHD is unknown. Besides BTK, ibrutinib also inhibits interleukin-2 inducible T-cell kinase (ITK), which is predominantly expressed in T-cells and a crucial enzyme for activating the downstream pathway of TCR signaling. ITK activates PLCγ2 and facilitates signaling through NF-κB, NFAT, and MAPK, leading to activation and proliferation of T-cells and enhanced cytokine production. Therefore, the TCR signaling pathway is indispensable for development of acute GVHD, and ITK inhibition by ibrutinib would be a rational therapeutic approach. Case presentation: A 56-year-old male acute myeloid leukemia patient with Myeloid neoplasms with germline DEAD-box RNA helicase 41 (DDX41) mutation underwent cord blood transplantation and developed severe gastrointestinal (GI) acute GVHD which was refractory to steroids and mesenchymal stem cell therapy. While acute GVHD accommodated by multiple life-threatening GI bleeding events persisted, chronic cutaneous GVHD developed, and ibrutinib 420 mg/day was initiated from day 147 of transplant. Although ibrutinib was commenced targeting the chronic GVHD, unexpected and abrupt remission of acute GVHD along with remission of chronic GVHD was observed. Conclusion: Ibrutinib is a promising therapeutic for treating acute GVHD, and further studies are warranted.

Outcomes of transplant-eligible patients with myelodysplastic syndrome with excess blasts registered in an observational study: The JALSG-CS11-MDS-SCT.

Allogeneic hematopoietic stem cell transplantation (allo-SCT) is the sole curative therapy for myelodysplastic syndrome (MDS). However, whether bridging therapy (BRT) including azacitidine (AZA) and combination chemotherapy (CCT) prior to allo-SCT should be performed is unclear. We analyzed BRT and the outcomes of patients with myelodysplastic syndrome with excess blasts (MDS-EB) who were ≤ 70 years old at the time of registration for a prospective observational study to clarify the optimal allo-SCT strategy for high-risk MDS. A total of 371 patients were included in this study. Among 188 patients (50.7%) who were considered for allo-SCT, 141 underwent allo-SCT. Among the patients who underwent allo-SCT, 64 received AZA, 29 received CCT, and 26 underwent allo-SCT without BRT as the initial treatment. Multivariate analysis identified BRT as an independent factor influencing overall survival (AZA vs. without BRT, hazard ratio [HR] 3.33, P = 0.005; CCT vs. without BRT, HR 3.82, P = 0.003). In multivariate analysis, BRT was independently associated with progression-free survival (AZA vs. without BRT: HR, 2.23; P = 0.041; CCT vs. without BRT: HR, 2.94; P = 0.010). Transplant-eligible patients with MDS-EB should undergo allo-SCT when clinically acceptable, and upfront allo-SCT without BRT may be superior to AZA or CCT.

Eltrombopag for the Treatment of Allogeneic Hematopoietic Stem Cell Transplantation-Related Poor Graft Function.

INTRODUCTION: Allogeneic stem cell transplantation (ASCT) is a crucial therapeutic strategy for hematological and non-hematological disorders. Poor graft function (PGF) after ASCT presents a critical challenge that does not have a standardized treatment approach. A thrombopoietin-mimetic oral drug eltrombopag shows promise in some bone failure syndromes. This study aimed to analyze the efficacy of eltrombopag in treating PGF after ASCT. METHODS: Patients receiving eltrombopag for PGF after ASCT between 2017 and 2020 were retrospectively evaluated. Patients' characteristics, details for ASCT, timing, treatment, and possible contributors for PGF, response to eltrombopag treatment, and overall response rate (ORR) were analyzed.  Results: Eighteen patients were assessed. Eltrombopag treatment yielded a favorable response in 11 patients, resulting in an ORR of 61%. The ORR in secondary PGF was better than that in primary PGF (83% and 17% respectively). There was a marked enhancement in platelet and hemoglobin levels following eltrombopag treatment (p=0.001 and p=0.030, respectively), while neutrophil values exhibited no significant change (p=0.8). Among the responding patients, four individuals (22%) underwent a tapering and discontinuation of eltrombopag. No toxicity was observed above grade one, and no patient discontinued eltrombopag because of intolerability or adverse events. CONCLUSION: Our findings affirm that eltrombopag can treat poor graft function after allogeneic stem cell transplantation without significant toxicities. These results contribute to the growing body of evidence supporting the use of eltrombopag in poor graft function after allogeneic stem cell transplantation, providing insights into its potential benefits and limitations.

Azacitidine and lenalidomide combination: a novel relapse prophylaxis regimen after allogeneic hematopoietic stem-cell transplantation in patients with acute myeloid leukemia.

Introduction: While allogeneic hematopoietic stem cell transplantation (allo-HSCT) can be a curative regimen for acute myeloid leukemia (AML), relapse of AML remains a serious risk post-transplantation. Once relapsed, salvage options are limited and management of AML is difficult. Here we designed a prospective study to examine the efficacy and tolerability of maintenance therapy with azacytidine (AZA) plus low-dose lenalidomide (LEN) to prevent relapse after allo-HSCT for AML patients (ChiCTR2200061803). Methods: AML patients post-allo-HSCT were treated with AZA (75 mg/m2 for 7 days), followed by LEN (5 mg/m2, day 10-28), and a 4-week resting interval, which was defined as one treatment cycle. A total of 8 cycles was recommended. Results: 37 patients were enrolled, 25 patients received at least 5 cycles, and 16 patients finished all 8 cycles. With a median follow-up time of 608 (43-1440) days, the estimated 1-year disease free survival (DFS) was 82%, cumulative incidence of relapse (CIR) was 18%, and overall survival (OS) was 100%. Three patients (8%) had grade 1-2 neutropenia without fever; one patient developed grade 3-4 thrombocytopenia and minor subdural hematoma; 4/37 patients (11%) developed chronic GVHD with a score of 1-2, without requiring systemic treatment; No patient developed acute GVHD. After AZA/LEN prophylaxis, increasing numbers of CD56+NK and CD8+ T, and decreasing of CD19+ B cells were observed. Discussion: Azacitidine combined with low-dose lenalidomide was observed to be an effective relapse prophylaxis option after allo-HSCT in AML patients, and can be administered safely without significantly increasing the risk of GVHD, infection and other AEs. Clinical Trial Registration: www.chictr.org, identifier ChiCTR2200061803.

Antibody, cell-mediated response and infection susceptibility in allogeneic hematopoietic stem cell recipients after COVID-19 mRNA vaccination.

BACKGROUND: Patients undergoing allogeneic stem-cell transplantation (allo-SCT) have reduced responses to vaccines due to immunosuppressive status linked to GvHD prophylaxis and treatment. In our study, we compared humoral responses to anti-SARS-CoV-2 mRNA vaccine, and infection onset, according to patients and transplant features; we also evaluated cellular response in patients without seroconversion. METHODS: We tested antibodies titer after second and third vaccine doses. Antibodies were detected through an immune-enzymatic assay. In a patients' subgroup without seroconversion, we tested cell-mediated responses evaluating interferon-gamma release by T-lymphocytes exposed to virus spike protein. RESULTS: Seroconversion rate increased from 66% at 30 days to 81% at 90 days after the second dose; it was 97% at 150 days after the third dose. We found a significant association between seroconversion after the second dose and two variables: shorter interval between allo-SCT and vaccination; ongoing immunosuppression. Twelve of 19 patients (63%) without antibodies after the second dose did not show cellular responses. Nineteen percent of patients developed SARS-CoV-2 infection after the third dose, with favorable outcome in all cases. Patients within 12 months after allo-SCT showed a significantly higher infection risk. CONCLUSIONS: Our study suggests that an interval shorter than 12 months between allo-SCT and first vaccine dose and/or ongoing immunosuppression were associated with humoral and cellular response deficiency after two doses. Third dose induced an increased and sustained humoral response in the majority of patients. However, patients within 1 year after allo-SCT remained at higher infection risk and may be candidate for prophylaxis with anti-SARS-CoV-2 monoclonal antibodies.

Therapy-related myeloid neoplasms of recipient origin after allogeneic hematopoietic stem cell transplantation for acute leukemia.

Some allogeneic stem cell transplantation (allo-SCT) recipients develop therapy-related myeloid neoplasms (t-MNs) of recipient origin with features including karyotypically abnormal hematopoiesis without cell dysplasia and myeloblast increase. However, due to their rarity their clinical course remains unclear. We report six cases of t-MN in patients with chromosomal abnormalities (CAs) after autologous recovery following allo-SCT for acute leukemia. CAs were first detected at a median interval of 422 (range 30-1941) days from allo-SCT. The fraction of CA-bearing cells of recipient origin increased with time, and cytogenetic relapse of underlying disease was not observed. Continuous emergence of identical autologous CAs was observed in one patient who did not receive total body irradiation (TBI). The other five patients received TBI, and complex karyotypes with the appearance of different types of CAs were the most dominant feature. Despite the persistence of complex abnormalities in the irradiated patients, no patient developed therapy-related acute myeloid leukemia (t-AML). TBI appears to be the major cause of t-MN of recipient origin with different types of CAs. Although t-MNs in patients receiving TBI do not initially seem to evolve to overt t-AML, they were associated with higher risk of underlying disease and greater oncogenic potential of irradiation.

The Clinical Characteristics and Prognosis of AYA and Older Adult ETP-ALL/LBL: A Real-World Multicenter Study in China.

Early T-cell precursor (ETP) lymphoblastic leukemia/lymphoma is a high-risk T lymphoblastic leukemia/lymphoma (T-ALL/LBL) subgroup. We performed a real-world multicenter study to explore the clinical characteristics and prognosis of adolescent and young adults (AYA) and older adult ETP leukemia/lymphoma. A total of 103 patients with ETP-ALL/LBL in five centers in China between January 2016 and February 2021 were included in this study. The median age was 29 years (range, 15-70 years). Next-generation sequencing was performed in 94 patients and revealed that NOTCH1 (35.1%, 33 cases) was the most frequently mutated gene, followed by JAK3 (16.0%, 15 cases), PHF6 (13.80%, 13 cases) and EZH2 (11.70%, 11 cases). Complete remission (CR) was obtained in 74.2% (72/97) of patients, and 6 relapsed/refractory patients received a decitabine combined with AAG priming regimen as reinduction therapy with a CR rate of 50%. With a median follow-up of 18 months (0.5-60 months), the 2-year overall survival (OS) and relapse-free survival (RFS) rates for the entire cohort were 54% and 57.7%, respectively. Allogeneic stem cell transplantation (allo-SCT) was performed in 59.8% (58/97) of patients. After landmark analysis at 6 months, the 2-year OS rates was 77% of patients with allo-SCT at CR1 and 25% of patients with chemotherapy alone (p < 0.001). A multivariate analysis suggested that allo-SCT and CR after the first course induction were independent prognostic factors for OS. Collectively, we reported the largest cohort study with AYA and older adult ETP-ALL/LBL, and we found that ETP-ALL/LBL was highly invasive and had a poor long-term prognosis. Allo-SCT could significantly improve ETP-ALL/LBL patient survival.

CpG-Activated Regulatory B-Cell Progenitors Alleviate Murine Graft-Versus-Host-Disease.

Development of Graft Versus Host Disease (GVHD) represents a major impediment in allogeneic hematopoietic stem cell transplantation (HSCT). The observation that the presence of bone marrow and circulating hematogones correlated with reduced GVHD risks prompted us to evaluate whether B-cell progenitors, which provide protection in various autoimmune disease models following activation with the TLR-9 agonist CpG (CpG-proBs), could likewise reduce this allogeneic disorder. In a murine model of GVHD that recapitulates an initial phase of acute GVHD followed by a phase of chronic sclerodermatous GVHD, we found that CpG-proBs, adoptively transferred during the initial phase of disease, reduced the diarrhea score and mostly prevented cutaneous fibrosis. Progenitors migrated to the draining lymph nodes and to the skin where they mainly differentiated into follicular B cells. CpG activation and IFN-γ expression were required for the protective effect, which resulted in reduced CD4+ T-cell-derived production of critical cytokines such as TGF-ß, IL-13 and IL-21. Adoptive transfer of CpG-proBs increased the T follicular regulatory to T follicular helper (Tfr/Tfh) ratio. Moreover, CpG-proBs privileged the accumulation of IL-10-positive CD8+ T cells, B cells and dendritic cells in the skin. However, CpG-proBs did not improve survival. Altogether, our findings support the notion that adoptively transferred CpG-proBs exert immunomodulating effect that alleviates symptoms of GVHD but require additional anti-inflammatory strategy to improve survival.

Outcomes of second allogeneic stem cell transplantation and anti-relapse strategies in patients with relapsed/refractory acute myeloid leukemia: A unicentric retrospective analysis.

Second allogeneic stem cell transplantation (allo-SCT2) represents a rescue option for selected patients (pts) with relapsed/refractory (r/r) acute myeloid leukemia (AML). Still, relapse rates post-allo-SCT2 remain high and effective anti-relapse strategies and predictive biomarkers remain to be defined. We here analyzed a cohort of 41 AML patients (pts) undergoing allo-SCT2 in our center. Allo-SCT2 induced a third hematologic complete remission (CR) in 37 pts, at costs of a 36% non-relapse mortality rate. Furthermore, 19 pts eventually relapsed post allo-SCT2. Addressing relapse after allo-SCT2, 14 pts (74%) underwent cell-based anti-relapse strategies, including third allogeneic transplantation (allo-SCT3; 3/14), donor lymphocyte infusions (DLIs) combined with either 5-azacytidin and venetoclax (4/14) or chemotherapeutic agents (7/14). Notably, six of seven pts (86%) who received either allo-SCT3 or a combination therapy of DLIs, 5-azacytidine and venetoclax achieved CR despite poor cytogenetics post-allo-SCT2 (e.g., TP53). Finally, 11 of 41 pts were alive at the last follow-up (seven CR2, three CR3, one partial remission) resulting in estimated 2- and 5-year overall survival of 35% and 25%, respectively.

Clinical roles of TIM-3 in myeloid malignancies and its importance in cellular therapy.

Acute myeloid leukemia (AML), one of the most common hematological malignancies worldwide, is derived from a fraction of stem cells known as leukemic stem cells (LSCs), which possess self-renewal and high propagation capacities. Remaining quiescent and being resistant to conventional chemotherapy, residual LSCs after chemotherapy drive leukemia regrowth, leading to AML relapse. Therefore, the eradication of LSCs is critical for the treatment of AML. We previously identified hepatitis A virus cellular receptor 2 (HAVCR2/TIM-3) as an LSC-specific surface molecule by comparing gene expression in LSCs and hematopoietic stem cells (HSCs). TIM-3 expression clearly discriminated LSCs from HSCs within the CD34+CD38- stem cell fraction. Furthermore, AML cells secrete galectin-9, a TIM-3 ligand, in an autocrine manner, leading to constitutive TIM-3 signaling that maintains the self-renewal capacity of LSCs via the induction of ß-catenin accumulation. Thus, TIM-3 is an indispensable functional molecule for human LSCs. Herein, we review the functional aspects of TIM-3 in AML and evaluate minimal/measurable residual disease with a focus on CD34+CD38-TIM-3+ LSCs. Using sequential genomic analysis of identical patients, we determined that CD34+CD38-TIM-3+ cells in the complete remission (CR) phase after allogeneic stem cell transplantation (allo-SCT) are the LSCs responsible for AML relapse. We retrospectively evaluated the incidence of TIM-3+ residual LSCs. All analyzed patients achieved CR and complete donor chimerism at the engraftment phase; however, the high frequency of residual TIM-3+ LSCs within the CD34+CD38- fraction at engraftment was a significant and independent risk factor for relapse. Residual TIM-3+ LSC levels in the engraftment phase had a stronger impact on relapse than did pre-SCT disease status. Therefore, the evaluation of residual TIM-3+ LSCs is a promising approach for predicting leukemia relapse after allo-SCT.

Outcomes of Philadelphia Positive Acute Lymphoblastic Leukemia in Adolescent and Young Adults.

Background Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) accounts for 25% of acute lymphoblastic leukemia cases in the adolescent and young adult (AYA) age subgroup. It is associated with poor outcomes and is considered a standard indication for allogeneic stem cell transplant (Allo-SCT). Improved outcomes have been reported with addition of tyrosine kinase inhibitors (TKIs) to chemotherapy in children and the role of Allo-SCT is now being debated in the first remission. Complete response (CR) at three months is associated with improved survival even without Allo-SCT in first CR. In this study, we have analyzed disease-free survival (DFS), overall survival (OS), and factors affecting survival outcomes of Ph+ ALL in the AYA subgroup, in resource-limited settings treated with chemotherapy and TKIs. Materials and methods This is a retrospective, multicenter cohort study of Ph+ ALL AYA patients, aged 18-40 years, and registered between January 2015 and December 2020. Primary objectives are to calculate disease-free survival (DFS) and overall survival (OS). Secondary objectives are to identify prognostic factors affecting response rates and outcomes. List of cases was obtained from hospital information system (HIS) and data were collected from patient case notes and electronic medical records. Data analysis was done utilizing the SPSS statistical program (Armonk, NY: IBM Corp.). Results Forty-nine patients were identified with Ph+ ALL with a median age of 23 years (range: 18-40 years) and a male-to-female ratio of 2.5:1. None of the patients had central nervous system (CNS) disease. White cell count was >30,000 per mm3 in 26% of patients, while 13% had additional cytogenetic abnormalities. Thirty-three percent patients received adult (hyper-cyclophosphamide, vincristine, Adriamycin, and dexamethasone {CVAD}) protocols while 67% received pediatric-inspired (Berlin-Frankfurt-Munster {BFM} 2000 or UK-ALL 2003/2011) protocols. TKI therapy was received by 66% of patients during treatment (early: 37%; late: 29%) and 34% did not receive TKIs due to financial constraints. CR after induction was achieved in 69% cases. Induction mortality was 16%. The median DFS for the entire cohort was 27 months (0.93-53.06) and the median OS was 29 months (8.89-49.10). The median OS in Allo-SCT group was not reached vs 8.0±8.8 months (p=0.05) with chemotherapy only. The OS was significantly better in patients with no additional cytogenetic abnormalities, pediatric-inspired chemotherapy protocols, early use of TKIs in induction phase, Allo-SCT, and post-Allo-SCT use of TKIs. Conclusion Addition of TKIs to pediatric-inspired chemotherapy protocols in Ph+ ALL AYA patients and Allo-SCT results in better overall survival. TKI availability remains a significant issue in low-income countries due to significant financial burden on the patients. Allo-SCT continues to be an attractive option, particularly in low-income countries providing an option for cure in Ph+ ALL.

Hypomethylating Agent-Based Combination Therapies to Treat Post-Hematopoietic Stem Cell Transplant Relapse of Acute Myeloid Leukemia.

Allogeneic stem cell transplantation still represents the best curative option for most patients with acute myeloid leukemia, but relapse is still dramatically high. Due to their immunologic activity and safety profile, hypomethylating agents (HMAs) represent an interesting backbone for combination therapies. This review reports mechanism of action, safety, and efficacy data on combination strategies based on HMAs in the setting of post-allogeneic stem cell transplant relapse. Several studies highlighted how HMAs and donor lymphocyte infusion (DLI) combination may be advantageous. The combination strategy of HMA with venetoclax, possibly in association with DLI, is showing excellent results in terms of response rate, including molecular responses. Lenalidomide, despite its well-known high rates of severe graft-versus-host disease in post-transplant settings, is showing an acceptable safety profile in association with HMAs with a competitive response rate. Regarding FLT3 internal tandem duplication (ITD) mutant AML, tyrosine kinase inhibitors and particularly sorafenib have promising results as monotherapy and in combination with HMAs. Conversely, combination strategies with gemtuzumab ozogamicin or immune checkpoint inhibitors did not show competitive response rates and seem to be currently less attractive strategies. Associations with histone deacetylase inhibitors and isocitrate dehydrogenase 1 and 2 (IDH1/2) inhibitors represent new possible strategies that need to be better investigated.

Extraordinarily elevated CD33 expression in CD56+CD3- cells in the bone marrow of a patient with relapsed acute myeloid leukemia: a case report.

Based on genetic risk allogeneic stem cell transplantation (allo-SCT) is the only curative treatment for some forms of acute myeloid leukemia (AML). However, post-transplantation relapse remains a frequent cause of transplantation failure. Natural killer (NK) cells and CD8+ T cells are important effector lymphocytes with pivotal roles in tumor surveillance and anti-tumor immune response. In this study, a 14-year-old female patient with AML was treated with allogeneic peripheral blood stem cell transplantation (allo-PBSCT). Bone marrow relapse was found 6 months later. Thereafter, the patient was treated with DAE (daunorubicin, cytosine arabinoside, and etoposide), followed by IAE (idarubicin, cytosine arabinoside, and etoposide), and then MA (mitoxantrone and cytosine arabinoside) regimens. A series of experiments including Wright-Giemsa stain analyses, cytogenetic analysis and flow cytometry were conducted to investigate the characteristic of the patient. Although there was a short remission after the DAE regimen, the patient experienced another relapse after finishing the MA regimen. The CD56+CD3‒ cells in the bone marrow showed severely impaired activation and anti-tumor function, while extraordinarily increased CD33 expression. Moreover, the proportion of multifunctional effector CD8+ T cells remained stable, though they had high PD-1 expression. These findings revealed the dysfunction of abnormal CD56+CD3- cells with high CD33 expression, which might be targetable and related to the relapsed/refractory AML after allo-SCT.

Allogeneic stem cell transplantation in AML with t(6;9)(p23;q34);DEK-NUP214 shows a favourable outcome when performed in first complete remission.

Acute myeloid leukaemia (AML) with t(6;9)(p23;q34) is a poor-risk entity, commonly associated with FLT3-ITD (internal tandem duplication). Allogeneic stem-cell tranplantation (allo-SCT) is recommended, although studies analysing the outcome of allo-SCT in this setting are lacking. We selected 195 patients with t(6;9) AML, who received a first allo-SCT between 2000 and 2016 from the EBMT (European Society for Blood and Marrow Transplantation) registry. Disease status at time of allo-SCT was the strongest independent prognostic factor, with a two-year leukaemia-free survival and relapse incidence of 57% and 19% in patients in CR1 (first complete remission), 34% and 33% in CR2 (second complete remission), and 24% and 49% in patients not in remission, respectively (P < 0·001). This study, which represents the largest one available in t(6;9) AML, supports the recommendation to submit these patients to allo-SCT in CR1.

Immunological and Clinical Impact of Manipulated and Unmanipulated DLI after Allogeneic Stem Cell Transplantation of AML Patients.

Allogeneic stem cell transplantation (allo-SCT) is the preferred curative treatment for several hematological malignancies. The efficacy of allo-SCT depends on the graft-versus-leukemia (GvL) effect. However, the prognosis of patients with relapsed acute myeloid leukemia (AML) following allo-SCT is poor. Donor lymphocyte infusion (DLI) is utilized after allo-SCT in this setting to prevent relapse, to prolong progression free survival, to establish full donor chimerism and to restore the GvL effect in patients with hematological malignancies. Thus, there are different options for the administration of DLI in AML patients. DLI is currently used prophylactically and in the setting of an overt relapse. In addition, in the minimal residual disease (MRD) setting, DLI may be a possibility to improve overall survival. However, DLI might increase the risk of severe life-threatening complications such as graft-versus-host disease (GvHD) as well as severe infections. The transfusion of lymphocytes has been tested not only for the treatment of hematological malignancies but also chronic infections. In this context, manipulated DLI in a prophylactic or therapeutic approach are an option, e.g., virus-specific DLI using different selection methods or antigen-specific DLI such as peptide-specific CD8+ cytotoxic T lymphocytes (CTLs). In addition, T cells are also genetically engineered, using both chimeric antigen receptor (CAR) genetically modified T cells and T cell receptor (TCR) genetically modified T cells. T cell therapies in general have the potential to enhance antitumor immunity, augment vaccine efficacy, and limit graft-versus-host disease after allo-SCT. The focus of this review is to discuss the different strategies to use donor lymphocytes after allo-SCT. Our objective is to give an insight into the functional effects of DLI on immunogenic antigen recognition for a better understanding of the mechanisms of DLI. To ultimately increase the GvL potency without raising the risk of GvHD at the same time.

Outcomes of allogeneic stem cell transplantation for DLBCL: a multi-center study from the Kyoto Stem Cell Transplantation Group.

Allogeneic hematopoietic stem cell transplantation (allo-SCT) has been considered as a potentially curative treatment option for refractory or relapsed diffuse large B cell lymphoma (DLBCL) patients. However, there is little information available, especially for Japanese patients and in cord blood transplantation (CBT). We aimed to determine treatment outcomes of allo-SCT for DLBCL in the Kyoto Stem Cell Transplantation Group, a multi-institutional joint research group. Sixty-eight DLBCL patients who underwent their first allo-SCT between 2003 and 2016 were included. The median time from diagnosis to transplantation was 13.5 months. Thirty-one patients were in CR/PR at transplantation. Twenty-seven patients underwent CBT. The median follow-up for survivors was 44.2 months. Four-year overall survival (OS) and relapse-free survival (RFS) rates were 23% (95% CI, 13-35%) and 20% (95% CI, 11-31%), respectively. Cumulative incidences of non-relapse mortality and relapse were 23% and 57%, respectively. Patients in CR/PR at allo-SCT had better OS (4-year, 46% vs 4%, P < 0.001) and RFS (4-year, 36% vs 7%, P = 0.005). The source of the stem cell did not significantly affect OS (4-year, bone marrow vs cord blood vs peripheral blood, 28.6% vs 27.2% vs 6.5%, P = 0.193). In multivariate analysis, non-remission status at SCT associated with inferior OS and RFS. Duration from diagnosis to transplantation of less than 1 year associated with inferior RFS. Allo-SCT, including CBT, may be a promising therapeutic modality for DLBCL patients who have good disease control at transplantation.