Sorafenib maintenance after allogeneic stem cell transplantation in patients with FLT3+ AML receiving midostaurin during induction and consolidation: a retrospective analysis.

Introduction: Acute myeloid leukemia (AML) relapse is the main cause of death after allogeneic stem cell transplant (allo-SCT). In AML FLT3+, it was shown that Sorafenib used as maintenance therapy after allo-SCT, significantly reduces the risk of relapse and death. Methods: We analyzed 29 adult patients with FLT3m AML and underwent allogeneic stem cell transplant from 2019 to 2023. All patients received midostaurin plus conventional CT during induction and consolidation. After transplantation, Sorafenib maintenance was administered in all patients independently from MRD status at transplantation. Results: Sorafenib maintenance was applied in 18 patients out 29 patients (62%). Median time to start sorafenib was 100 days (range 37-225) and median duration of treatment was 775 days (range 140-1064). For the whole population (n=29), 2-year OS, LFS, and CIR was 76%, 68% and 28%, respectively. The median time to relapse was 137 days (range 49-246). For patients treated with sorafenib (n=18), the 2-year OS, LFS, and CIR were 94%, 84% and 11%, respectively. For the whole population, the 100-day NRM was 0% and 1-year NRM was 3%. Death was caused by transplant-associated thrombotic microangiopathy in 1 patient. For patients who were administered with Sorafenib, the 1-y NRM was 5%. Death was caused by transplant associated transplant-associated thrombotic microangiopathy. Discussion: This retrospective study suggests that sorafenib maintenance seem to be effective even in patients pre-treated with midostaurin.

The impact of donor-specific antibodies' presence on the outcome post-allogeneic hematopoietic stem cell transplantation: a survey from a single center.

Introduction: Donor-specific antibodies (DSAs) correspond to anti-HLA antibodies of the recipient that are specifically directed to a mismatched antigen of the donor. In the setting of solid organ transplantation DSAs are associated with rejection. Their role is still debated in allogeneic cell transplantation. International guidelines recommend testing patients for DSA before transplant, and if possible, choosing a donor with negative screening. Methods: We collected clinical data of 236 recipients of alloSCT, performed at our institution from March 2019 to October 2023, to evaluate their impact on engraftment. Serum from all patients was tested for DSA. Results: 186 patients (79%) achieved sustained myeloid engraftment within day 30 post alloSCT. Thirty-two out 236 (13%) patients engrafted after day 30 post alloSCT. The median times to neutrophil engraftment and platelet engraftment were respectively 21 days (range 11-121 days) and 19 days (range 10-203 days). Fourteen out 236 patients (6%) experienced PrGF. .Twenty-nine patients (12 %) were DSA-positive. Among 29 patients with DSA positivity, 17 had a haploidentical donor and 12 had a UD donor. DSA positivity directly correlates respectively with neutrophil and platelets engraftment failure at 30 days after alloSCT (p=0.01 and p= 0.0004). Univariate Cox analysis showed that factors, including DSAs positivity, disease type, disease status, donor type, conditioning regimen, patient's age, and CD34+ were correlated with neutrophil and platelet engraftment failure at 30 days after alloSCT. Younger patients with DSA negativity, with acute leukemia, in complete response at the time of transplant, who received a higher dose of CD34+ cells from a sibling donor after a myeloablative conditioning regimen, have a reduced risk of neutrophil and platelet engraftment failure at day +30 post alloSCT.Multivariate analysis confirmed the impact of the presence of DSA only for platelet engraftment, confirming the role of type and status disease, donor type, recipient age, and CD34+ cells infused on engraftment. DSA presence has no impact on TRM, DFS, and OS. Discussion: PrGF has a multifactorial pathogenesis, where DSA is not the only player, but its impact could vary depending on the transplant platform. Thus patient screening may be helpful to choose the best donor and transplant strategy.

Early autologous and/or allogeneic stem cell transplantation for adult patients with advanced stage T- lymphoblastic leukemia/lymphoma or Burkitt lymphoma. A retrospective single-centre analysis.

T-cell acute lymphoblastic leukemia/lymphoma (T-ALL/LBL) and Burkitt lymphoma (BL) are uncommon, highly aggressive diseases originating either from immature precursor T cells or from mature B cells in BL. We retrospectively analyzed the outcome of an early autologous and/or allogeneic stem cell transplantation (SCT) concept in 28 patients with advanced stage T-ALL/LBL and BL after three to four remission induction/consolidation chemotherapy cycles. Considering only patients in first complete remission (CR), the 5-year overall survival (OS) and event-free survival (EFS) was 91% in patients with BL and 73% in patients with T-ALL/LBL with a 5-year relapse incidence (RI) of 9% in patients with BL and 27% in patients with T-ALL/LBL. All relapsing patients finally succumbed to the disease (n = 10) or complications/toxicity after having received a salvage allogeneic transplant (n = 5). Despite the low patient number our retrospective single-centre analysis by incorporating an early intensive high-dose chemo-/radiotherapy strategy with either autologous or allogeneic stem cell transplantation, although preliminary, show promising long-term outcome. Further studies are highly warranted to better define those patients who might benefit most from such a treatment approach.

Role of Endoscopic Techniques in the Diagnosis of Complications of Allogeneic Hematopoietic Stem Cell Transplantation: A Review of the Literature.

Allogeneic stem cell transplantation (Allo-SCT) implies that a donor and a recipient are not genetically identical. Allo-SCT is used to cure a variety of conditions, including hematologic malignancies using the graft versus tumor effect, nonmalignant hematologic, immune deficiencies, and, more recently, genetic disorders and inborn errors of metabolism. Given the immunosuppressive and myeloablative nature of some of the conditioning chemotherapy regimens used during the Allo-SCT, patients are often at high risk of infection, including viral infections affecting the gastrointestinal tract, following the transplant. Furthermore, other complications such as hepatic sinusoidal obstruction syndrome (SOS) or graft-versus-host disease may occur post-transplant and may require endoscopy to assist in the diagnosis. This review will provide newer insights into the importance of endoscopic techniques in the diagnosis of post-Allo-SCT complications with a focus on safety and timing.

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.

Improved Outcome of Allogeneic Transplantation in Older Patients Treated for Myeloid Malignancies Using Post-Transplantation Cyclophosphamide and Reduced Duration of Immune Suppression.

Allogeneic stem cell transplantation (alloSCT) offers curative potential for older patients with myeloid malignancies. We evaluated the efficacy and safety of alloSCT using post-transplantation cyclophosphamide (PTCy) in combination with a very short duration of immune suppression (IS) in this population. We retrospectively analyzed 92 consecutive patients aged 65 years and older who underwent an alloSCT for myeloid malignancies between February 2018 and December 2022 at our institution. Data on patient characteristics, treatment modalities, and outcomes were collected. Ninety-two patients received an alloSCT with PTCy-based graft versus host disease (GVHD) prophylaxis. The majority had minimal comorbidities and were diagnosed with acute myeloid leukemia. Patients mostly received conditioning regimens with low to intermediate transplant conditioning intensity scores. In 43% of patients, IS could be permanently stopped at day +90, resulting in a median time of IS of 2.93 months in high-risk patients. At a median follow-up of 21.3 months, the 1- and 2-year overall survival rates were 89% and 87%, respectively. Relapse-free survival rates were 88% and 84% at 1 and 2 years, respectively. The 1- and 2-year cumulative incidences of relapse were 8% and 13%, while treatment-related mortality (TRM) estimates were 9% at both time points. Acute GVHD grade 3 to 4 occurred in 7% within the first 180 days and severe chronic GVHD in 6% of patients. This all resulted in a 1- and 2-year graft versus host and relapse-free survival of 74% and 70%, respectively. AlloSCT using PTCy in combination with a short duration of IS in older patients with myeloid malignancies demonstrates favorable survival outcomes due to low relapse rates and a low TRM. The low incidence of relapse and acceptable rates of graft-versus-host disease suggest the efficacy and safety of this approach. Further studies are warranted to validate these findings and optimize transplant strategies for older patients with myeloid malignancies.

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.

Recent Advances towards the Understanding of Secondary Acute Myeloid Leukemia Progression.

Secondary acute myeloid leukemia (sAML) is a heterogeneous malignant hematopoietic disease that arises either from an antecedent hematologic disorder (AHD) including myelodysplastic syndromes (MDS), myeloproliferative neoplasms (MPN), aplastic anemia (AA), or as a result of exposure to genotoxic chemotherapeutic agents or radiotherapy (therapy related AML, tAML). sAML is diagnosed when the number of blasts is ≥20% in the bone marrow or peripheral blood, and it is characterized by poor prognosis, resistance to therapy and low overall survival rate. With the recent advances in next generation sequencing technologies, our understanding of the molecular events associated with sAML evolution has significantly increased and opened new perspectives for the development of novel therapies. The genetic aberrations that are associated with sAML affect genes involved in processes such as splicing, chromatin modification and genome integrity. Moreover, non-coding RNAs' emerged as an important contributing factor to leukemogenesis. For decades, the standard treatment for secondary AML has been the 7 + 3 regimen of cytarabine and daunorubicin which prolongs survival for several months, but modifications in either dosage or delivery has significantly extended that time. Apart from traditional chemotherapy, hematopoietic stem cell transplantation, CAR-T cell therapy and small molecule inhibitors have also emerged to treat sAML.

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.

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.

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.

Promiscuity of Peptides Presented in HLA-DP Molecules from Different Immunogenicity Groups Is Associated With T-Cell Cross-Reactivity.

In the context of HLA-DP-mismatched allogeneic stem cell transplantation, mismatched HLA-DP alleles can provoke profound allo-HLA-DP-specific immune responses from the donor T-cell repertoire leading to graft-versus-leukemia effect and/or graft-versus-host disease in the patient. The magnitude of allo-HLA-DP-specific immune responses has been shown to depend on the specific HLA-DP disparity between donor and patient and the immunogenicity of the mismatched HLA-DP allele(s). HLA-DP peptidome clustering (DPC) was developed to classify the HLA-DP molecules based on similarities and differences in their peptide-binding motifs. To investigate a possible categorization of HLA-DP molecules based on overlap of presented peptides, we identified and compared the peptidomes of the thirteen most frequently expressed HLA-DP molecules. Our categorization based on shared peptides was in line with the DPC classification. We found that the HLA-DP molecules within the previously defined groups DPC-1 or DPC-3 shared the largest numbers of presented peptides. However, the HLA-DP molecules in DPC-2 segregated into two subgroups based on the overlap in presented peptides. Besides overlap in presented peptides within the DPC groups, a substantial number of peptides was also found to be shared between HLA-DP molecules from different DPC groups, especially for groups DPC-1 and -2. The functional relevance of these findings was illustrated by demonstration of cross-reactivity of allo-HLA-DP-reactive T-cell clones not only against HLA-DP molecules within one DPC group, but also across different DPC groups. The promiscuity of peptides presented in various HLA-DP molecules and the cross-reactivity against different HLA-DP molecules demonstrate that these molecules cannot be strictly categorized in immunogenicity groups.