Chimeric antigen receptor and bispecific T-cell engager therapies in multiple myeloma patients with prior allogeneic transplantation.

Chimeric antigen receptor T-cell (CAR-T) therapy and bispecific T-cell engagers (BsAb) have emerged as promising immunotherapeutic modalities in patients with relapsed and/or refractory multiple myeloma (RRMM). However, there is limited data on the safety and efficacy of CAR-T and BsAb therapies in MM patients with a prior history of allogeneic transplantation (allo-HCT). Thirty-three MM patients with prior allo-HCT received CAR-T (n = 24) or BsAb (n = 9) therapy. CAR-T therapy demonstrated an ORR of 92% (67% ≥ CR), and 73% were MRD negative. BsAb therapy resulted in an ORR of 44% (44% ≥ CR) and 44% MRD negative. Safety analysis showed grade ≥3 AEs in 92% of CAR-T and 56% of BsAb patients. Cytokine release syndrome (CRS) occurred in 83% of CAR-T and 78% of BsAb recipients, while immune effector cell-associated neurotoxicity syndrome (ICANS) was observed in three CAR-T patients. Infections of grade ≥3 were reported in 50% of CAR-T and 44% of BsAb recipients. No exacerbation of graft-versus-host disease occurred except in one BsAb recipient. CAR-T and BsAb therapies appear to be feasible, safe and provide deep and durable responses in MM patients with prior allo-HCT.

The life threat in hematopoietic allogeneic stem cell transplantation - an interview and focus group study on health care professionals' perspectives.

Understanding healthcare professionals' (HCPs) experiences with patients undergoing hematopoietic allogeneic stem cell transplantation (allo-HSCT) is crucial, given its dual nature of offering a hope for cure which on the other hand is accompanied by a high risk for morbidity and mortality. Yet, how HCPs experience their patients' existential threats remains unexplored. Qualitative thematic content analysis was employed to comprehend these experiences. This involved conducting three focus groups and 11 individual in-depth interviews with nurses and hematologists. We found that HCPs struggled to balance curative goals and the therapy's risks, while attempting to maintain their patients' hopes. The unpredictability of patient trajectories and their suffering burdened HCPs. Despite occasional disagreements within the team, (inter-)professional exchanges remained a crucial ressource, especially in addressing the patients' potential life threat. Team meetings and palliative care specialist supervisions were emphasized as vital for managing these challenges. HCPs sought support in communicating with patients about death-related issues and managing the transition from a curative to a palliative goal of care. Our research underscores the need for targeted support for HCPs and lays a groundwork for addressing their challenges. Trial registration number DRKS00027290 (German Clinical Trials Register). Date of trial registration January 10th, 2022.

High dose total marrow irradiation (TMI) does not increase long-term toxicity of myeloablative fludarabine/busulfan (FluBu4) conditioning regimen in allogeneic hematopoietic stem cell transplantation (HSCT).

OBJECTIVES: Based on a previous phase 1 study, total marrow irradiation (TMI) at 9Gy was added to a myeloablative FluBu4 conditioning regimen in allogeneic hematopoietic stem cell transplantation (HSCT) for myeloid malignancies. Here, we report on the long-term toxicity of TMI combined with FluBu4 and compare it to patients who received only FluBu4. METHODS: We retrospectively analyzed 38 consecutive patients conditioned with FluBu4/TMI (n = 15) or FluBu4 (n = 23, control group) who had at least 1 year follow-up post-transplant. The rate of long-term adverse events that have been previously associated with total body irradiation (TBI) was analyzed in the two groups. RESULTS: The baseline characteristics did not differ between the two groups. The control group had a longer median follow-up (71.2 mo) than the TMI group (38.5 mo) (p = .004). The most common adverse events were xerostomia, dental complications, cataracts, or osteopenia and did not differ between the two groups. Cognitive dysfunction or noninfectious pneumonitis, often detected after high dose TBI, were also not different in the two groups (p = .12 and p = .7, respectively). There was no grade 4 adverse event. CONCLUSION: Our results suggest that a conditioning regimen with TMI 9Gy and FluBu4 does not increase long-term adverse events after allogeneic HSCT.

Cytomegalovirus viral load at initiation of pre-emptive antiviral therapy impacts cytomegalovirus dynamics in pediatric allogeneic hematopoietic cell transplantation recipients.

BACKGROUND: Cytomegalovirus (CMV) contributes to morbidity and mortality in allogeneic hematopoietic cell transplantation (allo-HCT) recipients. Pre-emptive antiviral therapy (PET) reduces the incidence of CMV end-organ disease (EOD), though relevant viral thresholds to initiate PET remain undefined. We evaluated the impact of viral loads (VLs) at PET initiation on virologic and clinical outcomes following pediatric allo-HCT. METHODS: Single-center retrospective cohort analysis of children who underwent their first allo-HCT from January 2014 to December 2020. Weekly quantitative plasma CMV polymerase chain reaction was performed until Day +100 and PET was initiated once VL exceeded a pre-defined threshold per institutional guidelines. Patients were followed for 1-year post-HCT to evaluate virologic and clinical outcomes including end-organ disease (EOD), overall survival (OS), and non-relapse mortality (NRM). RESULTS: Among 146 allo-HCT recipients, CMV DNAemia occurred in 40 patients (27%) at a median of 15 days post-HCT (interquartile range 6-28.5). Ten percent (n = 4) had spontaneous resolution of DNAemia, while 90% (n = 36) required PET. PET initiated when CMV VL was ≥ 1000 IU/mL (n = 21) vs when VL < 1000 IU/mL (n = 15) resulted in higher peak CMV VL (12,670 vs. 1284 IU/mL, p = 0.0001) and longer time to CMV DNAemia resolution (36 vs. 24 days, p = 0.035). There were no differences in EOD, OS, or NRM at 12 months post-HCT based on VL at PET initiation. CONCLUSIONS: Initiating PET when CMV VL was ≥1000 IU/mL resulted in significantly higher peak VL and prolonged DNAemia, with no differences in EOD, OS, or NRM at 12 months post pediatric HCT.

Exploring the immunological relevance of pre-transplant donor-specific antibody in intestinal transplantation, with special consideration to the liver.

Despite recent advances that have improved outcomes following intestinal transplantation (ITx), achieving long-term patient survival and rejection-free survival is still challenging. Understanding the relevance of pre-transplant human leukocyte antigen (HLA) donor-specific antibody (DSA) in ITx and the immunomodulatory potential of the liver within the allograft is crucial to providing an accurate assessment of pre-transplant immunological risk, which could influence and improve post-transplant outcomes further. This was the primary objective of this retrospective study of 95 adult ITx transplants which took place at Cambridge University Hospitals (United Kingdom) between 2007 and 2019. Two novel programs were developed and validated to identify DSA (tested by Luminex single antigen beads) in this dataset. Data analysis utilised Kaplan-Meier survival methods, and statistical analysis was performed using log-rank tests and adjusted Cox models. Fifty-four (57%) ITx cases contained a liver, and 36 (38%) were sensitised to HLA. Pre-transplant DSA > 500 mean fluorescent intensity appeared to negatively affect post-ITx patient survival and rejection outcomes. Additionally, liver-inclusive allografts seemed to show particular resistance to HLA class I DSA. Our data hints towards consistency with other ITx studies where deleterious effects of DSA have been demonstrated, and where liver inclusion is protective from HLA class I DSA. This is in line with current national guidelines for immunological risk. Our publicly available research programs could support future large or multicentre studies where statistically relevant data might be gained.

Transplantation for myeloid neoplasms with antecedent solid tumor.

BACKGROUND: Definitive treatment of acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), and myeloproliferative neoplasm (MPN) involves allogeneic hematopoietic stem cell transplantation (allo-HSCT), either with myeloablative (MAC) or reduced-intensity conditioning (RIC). These diseases may arise in patients with a prior solid tumor. The impact of antecedent solid tumor on transplantation decision-making and outcomes is not well defined. METHODS: The authors performed a retrospective cohort study to address this question. A total of 1193 patients who underwent allo-HSCT for AML, MDS, or MPN between January 1, 2010 and December 31, 2018 were included, 102 of whom had a history of prior solid tumor. RESULTS: Patients with prior solid tumor were older (median age, 62.5 vs. 54.9 years; p < .00001) and more frequently were conditioned with RIC (52.5% vs. 27.2%; p < .00001). A higher incidence of acute graft-versus-host disease was observed in patients with prior solid tumor (73.5% vs 66.4%; adjusted odds ratio, 1.65; 95% confidence interval, 1.03-2.65; p = .037), yet overall survival and relapse did not significantly differ. Cytogenetic risk was the dominant risk factor for survival. CONCLUSIONS: Analysis by the authors suggests that patients with antecedent solid tumor and respective therapy can be transplanted successfully. Although selection bias is likely to be a factor, the results are encouraging for patients who come to transplantation after surviving a prior cancer.

Unrelated or haploidentical allogeneic hematopoietic cell transplantation in second complete remission for acute myeloid leukemia-Improved outcomes over time: A European Society for Blood and Marrow Transplantation Acute Leukemia Working Party study.

BACKGROUND: Allogeneic hematopoietic cell transplantation (allo-HCT) is the only cure for acute myeloid leukemia (AML) in second complete remission (CR2). Patients lacking a matched sibling donor (MSD) receive transplants from matched unrelated donors (MUDs), mismatched unrelated donors (MMUDs), haploidentical (haplo) donors, or cord blood. METHODS: This is a retrospective, registry-based European Society for Blood and Marrow Transplantation study that investigates changes in patient- and transplant-related characteristics and posttransplant outcomes over time. RESULTS: We identified 3955 adult patients (46.7% female; median age, 52 years [range, 18-78 years]) with AML in CR2 first transplanted between 2005 and 2019 from a MUD 10/10 (61.4%), MMUD 9/10 (21.9%), or haplo donor (16.7%) and followed for 3.7 years. A total of 725 patients were transplanted between 2005 and 2009, 1600 between 2010 and 2014, and 1630 between 2015 and 2019. Over the three time periods, there was a significant increase in patient age (from 48.7 to 53.5 years; p < .001), use of a haplo donor (from 4.6% to 26.4%; p < .001), and use of posttransplant cyclophosphamide (from 0.4% to 29%; p < .001). There was a significant decrease in total body irradiation and in vivo T-cell depletion. In multivariate analysis, transplants performed more recently had better outcomes. Leukemia-free survival (hazard ratio [HR], 0.79; p = .002) and overall survival (HR, 0.73; p < .001) increased over time. Similarly, nonrelapse mortality (HR, 0.64; p < .001) decreased over time. We also observed better graft-vs-host disease (GVHD) rates (acute GVHD II-IV: HR, 0.78; p = .03; GVHD-free, relapse-free survival: HR, 0.69; p < .001). CONCLUSIONS: Even in the absence of an MSD, outcomes of allo-HCT in CR2 for AML have significantly improved over time, with most favorable outcomes achieved with a MUD.

Allogeneic haematopoietic cell transplant in patients with relapsed/refractory anaplastic large cell lymphoma.

The prognosis of relapsed/refractory (R/R) anaplastic large cell lymphoma (ALCL) is poor. Large studies evaluating outcomes of allogeneic haematopoietic cell transplantation (allo-HCT) in systemic R/R ALCL are not available. Using the Center for International Blood and Marrow Transplant Research (CIBMTR) database, we evaluated outcomes of 182 adults (aged ≥18 years) with R/R ALCL undergoing allo-HCT between 2008 and 2019. Non-relapse mortality (NRM), disease relapse/progression (REL), progression-free survival (PFS), and overall survival (OS) were modelled using Cox proportional hazards models. The median (range) follow-up of survivors was 62 (3-148) months. The 1-year NRM was 18%. The 5-year REL, PFS and OS were 32%, 41% and 56% respectively. On multivariable regression analysis African American race (hazard ratio [HR] 2.7, 95% confidence interval [CI] 1.6-4.8; p < 0.001) and refractory disease at allo-HCT (HR 3.2, 95% CI 1.6-6.2; p < 0.001) were predictive of inferior OS. Similarly, African-American race (HR 2.1, 95% CI 1.3-3.4; p = 0.003), other minority race (HR 2.5, 95% CI 1.2-5.3; p = 0.02) and refractory disease (HR 2.2, 95% CI 1.2-4.3; p = 0.01) were predictive of inferior PFS. These data, demonstrate that allo-HCT can result in durable disease control in a sizable proportion of patients with R/R ALCL. Refractory disease and racial minority status predicted inferior allo-HCT outcomes. Whether the inferior outcomes of racial minorities with R/R ALCL after allo-HCT are driven by differences in disease biology or disparities in post allo-HCT care, or both, requires further investigation.

Salvage haploidentical or cord-blood allogeneic stem cell transplantation after a prior alternative allograft in hematologic malignancies: A retrospective study from the SFGM-TC.

BACKGROUND: Haploidentical (haplo-) donors and cord-blood (CB) stem cells provide alternative transplant options in patients lacking an HLA-matched donor. In case of relapse or graft failure after a first alternative allogeneic hematopoietic stem cell transplant (HSCT), a second alternative HSCT (HSCT2) is rarely considered due to a high risk of toxicity. METHODS: A retrospective French multicentre study was performed, including patients with hematologic malignancies who underwent two consecutive HSCT from alternative donors. All data were exported from the national ProMISE database between 2000 and 2016. RESULTS: Forty-three patients (61.4%) received a CB-HSCT2 and 27 (38.6%) a haplo-HSCT2. Indications for HSCT were graft failure (51.4%) or disease progression (48.6%). Two-years probabilities of overall survival, progression-free survival and toxicity-related mortality were 18.5%, 17.8% and 55.8%, respectively. In multivariate analysis, complete remission status at HSCT2 and year of HSCT2 ≥ 2012 were significantly associated with a better outcome (with respectively hazard ratio [HR] = 0.42, p = .002 and HR = 0.5, p = .051). CONCLUSIONS: Neither the indication of HSCT2 nor the source of stem cell was more advantageous towards overall patient survival. A salvage haploidentical or cord-blood stem cell transplantation is a high-risk procedure, that may be considered for patients achieving a complete remission before receiving the second HSCT.

The effect of cryopreservation on engraftment kinetics in fully matched allogeneic stem cell transplantation: Real-life data and literature review.

INTRODUCTION: The standard approach for allogeneic stem cell transplantation (allo-SCT) is to administer donor cells on the same day as a fresh product to a patient who has been given a preparative regimen. The difficulty in collecting and transporting donor cells, especially during the COVID-19 pandemic, has made it essential to collect and cryopreserve the grafts before the recipient begins the transplant preparation regimen. However, the short- and long-term impacts of cryopreservation on transplant outcomes remain controversial. MATERIALS AND METHODS: This retrospective study included 93 patients who underwent allo-SCT between January 2012 and August 2022 at the Stem Cell Transplant Unit of Bursa Uludag University Faculty of Medicine using frozen and fresh products of peripheral blood stem cells from a fully matched sibling donor. The effect of cryopreservation of donor grafts on engraftment kinetics was investigated. RESULTS: Frozen and fresh products were used in 37 and 56 patients, respectively. The majority of patients had acute myeloid leukemia and acute lymphoblastic leukemia. The median age at transplantation was 41 years. Neutrophil engraftment time was similar between the two groups (median: 14 vs. 16 days, p = 0.393). Platelet engraftment time was longer in the frozen product group (median: 12 vs. 15 days, p < 0.001). There was no statistically significant difference between freezing time and viability. The acute graft-versus-host disease (GVHD) rate was 37.8 % in the frozen product group and 28.6 % in the fresh product group (p = 0.349). There was no significant difference between the two groups in terms of primary and secondary graft failure, chronic GVHD, 30-day chimerism, relapse, overall survival, progression-free survival, and nonrelapse mortality. CONCLUSION: Having donor cells ready before transplantation significantly prevents donor-induced adverse events and provides confidence and practicality to both the clinician and the recipient. Allo-SCT with frozen products is a successful method that can be safely applied, especially when disruptions in donor-derived cell collection or transportation are foreseen.

BSHI and BTS UK guideline on the detection of alloantibodies in solid organ (and islet) transplantation.

Solid organ transplantation represents the best (and in many cases only) treatment option for patients with end-stage organ failure. The effectiveness and functioning life of these transplants has improved each decade due to surgical and clinical advances, and accurate histocompatibility assessment. Patient exposure to alloantigen from another individual is a common occurrence and takes place through pregnancies, blood transfusions or previous transplantation. Such exposure to alloantigen's can lead to the formation of circulating alloreactive antibodies which can be deleterious to solid organ transplant outcome. The purpose of these guidelines is to update to the previous BSHI/BTS guidelines 2016 on the relevance, assessment, and management of alloantibodies within solid organ transplantation.

Allogeneic haemopoietic cell transplant services in Australia and New Zealand in the first year of the COVID-19 pandemic: a report from Australia and New Zealand transplant and cellular therapies.

BACKGROUND: The COVID-19 pandemic has caused major disruption to health systems, with allogeneic haemopoietic cell transplant (alloHCT) services a particularly vulnerable area. Ongoing provision of alloHCT has required dynamic responses at national and local levels. In Australia and New Zealand (ANZ), a high reliance on unrelated donors from overseas registries has posed an additional challenge. AIMS: To describe the impact of COVID-19 on alloHCT services in ANZ in the first year of the pandemic. METHODS: Data from the national alloHCT patient and unrelated donor registries were extracted for a 2-year time frame. Comparisons were made between a pre-pandemic period of 1 March 2019 to 29 February 2020 and the corresponding dates during the pandemic, 1 March 2020 to 28 February 2021. RESULTS: There was a 13% decrease in the number of allogeneic transplants, a reversal of steady increases in previous years, with the largest decrease in unrelated donor transplants. Local donors supplied a greater proportion of unrelated stem cell products. With a switch to universal cryopreservation, the time from request of a product to infusion increased by a median of 25.5 days for overseas products and 14 days for local products. There was a significant increase in the number of products collected but not used. CONCLUSIONS: A strong public health response and coordinated transplant community activities allowed for safe provision of alloHCT in ANZ; however, our data suggest that the timely delivery of allogeneic transplants was affected by the COVID-19 pandemic. Continued dedicated efforts are required to minimise further impacts.

High dose valacyclovir for cytomegalovirus prophylaxis following allogeneic hematopoietic cell transplantation.

INTRODUCTION: Cytomegalovirus (CMV) is one of the most common and clinically significant viral infections following allogeneic hematopoietic cell transplantation (HCT). Currently available options for CMV prophylaxis and treatment present challenges related to side effects and cost. METHODS: In this retrospective medical record review, the incidence of clinically significant CMV infection (CMV disease or reactivation requiring preemptive treatment) following allogeneic HCT was compared in patients receiving valacyclovir 1 g three times daily versus acyclovir 400 mg every 12 h for viral prophylaxis. RESULTS: Forty-five patients who received valacyclovir were matched based on propensity scoring to 35 patients who received acyclovir. All patients received reduced-intensity conditioning regimens containing anti-thymocyte globulin. Clinically significant CMV infection by day + 180 was lower in the valacyclovir group compared to the acyclovir group (18% vs. 57%, p = 0.0004). Patients receiving valacyclovir prophylaxis also had less severe infection evidenced by a reduction in CMV disease, lower peak CMV titers, delayed CMV reactivation, and less secondary neutropenia. CONCLUSION: Prospective evaluation of valacyclovir 1 g three times daily for viral prophylaxis following allogeneic HCT is warranted. Due to valacyclovir's favorable toxicity profile and affordable cost, it has the potential to benefit patients on a broad scale as an option for CMV prophylaxis.

From 2D to 3D: Development of Monolayer Dopaminergic Neuronal and Midbrain Organoid Cultures for Parkinson's Disease Modeling and Regenerative Therapy.

Parkinson's Disease (PD) is a prevalent neurodegenerative disorder that is characterized pathologically by the loss of A9-specific dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc) of the midbrain. Despite intensive research, the etiology of PD is currently unresolved, and the disease remains incurable. This, in part, is due to the lack of an experimental disease model that could faithfully recapitulate the features of human PD. However, the recent advent of induced pluripotent stem cell (iPSC) technology has allowed PD models to be created from patient-derived cells. Indeed, DA neurons from PD patients are now routinely established in many laboratories as monolayers as well as 3D organoid cultures that serve as useful toolboxes for understanding the mechanism underlying PD and also for drug discovery. At the same time, the iPSC technology also provides unprecedented opportunity for autologous cell-based therapy for the PD patient to be performed using the patient's own cells as starting materials. In this review, we provide an update on the molecular processes underpinning the development and differentiation of human pluripotent stem cells (PSCs) into midbrain DA neurons in both 2D and 3D cultures, as well as the latest advancements in using these cells for drug discovery and regenerative medicine. For the novice entering the field, the cornucopia of differentiation protocols reported for the generation of midbrain DA neurons may seem daunting. Here, we have distilled the essence of the different approaches and summarized the main factors driving DA neuronal differentiation, with the view to provide a useful guide to newcomers who are interested in developing iPSC-based models of PD.

Cardiac Regeneration Using Pluripotent Stem Cells and Controlling Immune Responses.

Pluripotent stem cell (PSC)-derived cardiomyocytes are a promising source of cells in myocardial regeneration therapy for end-stage heart failure. Because most previous reports have focussed on xenotransplantation models using immunocompromised animals, studies on immune rejection in allogeneic transplantation models are needed for preclinical and clinical applications. Human leukocyte antigen (HLA) plays an important role in allogeneic transplantation, and cell bank projects are currently underway worldwide to stock induced pluripotent stem cells (iPSCs) generated from healthy individuals with homozygous HLA haplotypes. However, it is difficult to stock iPSCs that match the entire population in these cell banks; thus, several groups have produced hypoimmunogenic PSCs by knocking out HLA. These HLA-knockout PSCs were able to avoid rejection by T cells but still suffered rejection by natural killer (NK) cells caused by 'missing self-recognition'. Recent studies have attempted to generate hypoimmunogenic PSCs with gene editing to inhibit NK cell activation. Regenerative medicine using autologous iPSCs can be an ideal transplantation therapy, but, currently, there are major hurdles to its practical application. Hopefully, further research will resolve these issues. This review provides an overview of the current understanding and progress in this field.

A fair exchange: why living kidney donors in England should be financially compensated.

Every year, hundreds of patients in England die whilst waiting for a kidney transplant, and this is evidence that the current system of altruistic-based donation is not sufficient to address the shortage of kidneys available for transplant. To address this problem, we propose a monopsony system whereby kidney donors can opt-in to receive financial compensation, whilst still preserving the right of individuals to donate without receiving any compensation. A monopsony system describes a market structure where there is only one 'buyer'-in this case the National Health Service. By doing so, several hundred lives could be saved each year in England, wait times for a kidney transplant could be significantly reduced, and it would lessen the burden on dialysis services. Furthermore, compensation would help alleviate the common disincentives to living kidney donation, such as its potential associated health and psychological costs, and it would also help to increase awareness of living kidney donation. The proposed system would also result in significant cost savings that could then be redirected towards preventing kidney disease and reducing health disparities. While concerns about exploitation, coercion, and the 'crowding out' of altruistic donors exist, we believe that careful implementation can mitigate these issues. Therefore, we recommend piloting financial compensation for living kidney donors at a transplant centre in England.

Effect of Short PSG Peptides on Inflammatory Markers in Allogeneic Bone Marrow Cell Transplantation in Wistar Rats.

Short linear peptide fragments of placental trophoblastic ß1-glycoprotein (PSG) (YECE, YQCE, YVCS, and YACS) were studied in the context of their immunomodulatory effects at the level of inflammatory markers. The original host-versus-graft model was used in male Wistar rats without prior conditioning of recipient bone marrow. A composition of PSG peptide fragments was injected to animals after allogeneic transplantation of bone marrow cells in a dynamic experiment, inflammatory markers α1-acid glycoprotein (AGP, orosomucoid), α2-macroglobulin (α2M) were assayed by ELISA, and biochemical parameters (total protein, glucose, creatinine, and urea) were measured. The levels of α2M and AGP increased in response to allotransplantation, whereas administration of PSG peptides normalized serum α2M levels by the end of the experiment. The decrease in α2M level coincided with the independent effect of PSG peptide administration. The levels of total protein, glucose, creatinine, and urea in rat serum after allotransplantation were reduced throughout the experiment. Administration of PSG peptides contributed to normalization of serum total protein, creatinine, and urea levels by the end of the experiment. Administration of PSG peptides after allogeneic transplantation of bone marrow suspension contributed to normalization of the levels of α2M, total protein, creatinine, and urea, which can be interpreted as an anti-inflammatory effect of these peptides.

[Fatal invasive pneumococcal disease developed 14 years after allogeneic hematopoietic stem cell transplantation in a patient with myelodysplastic syndrome].

Invasive pneumococcal diseases (IPDs) after allogeneic hematopoietic stem cell transplantation have high fatality rates and often develop late after transplantation. The patient was a 58-year-old female. Fourteen years ago, she underwent bone marrow transplantation from a HLA-DR 1-antigen mismatched unrelated donor for myelodysplastic syndrome. She developed pneumonia, chronic graft-versus-host disease, and hypogammaglobulinemia. She received 23-valent pneumococcal capsular polysaccharide vaccine 11 and 6 years earlier. She was presented to our emergency room with fever. Her blood culture was positive for pneumococcus, and she was diagnosed with an IPD. The patient received antibiotic treatment but died on the third day of hospitalization. Because of its seriousness, pneumococcal infection should receive attention even 10 or more years after transplantation. Preventive approaches such as vaccination and early intervention at the time of diagnosis are important.

Therapy for isocitrate dehydrogenase 2 (IDH2)R172 -mutant acute myeloid leukaemia.

Although we earlier reported a very poor outcome for younger adult patients with isocitrate dehydrogenase 2 (IDH2)R172 -mutated acute myeloid leukaemia (AML) entered into UK trials compared to IDH2WT and IDH2R140 -mutated patients, this was not corroborated by a study from the German-Austrian AML Study Group. We have therefore investigated a later cohort of IDH2-mutated patients to identify any changes in outcome and whether this could inform the optimal treatment for IDH2R172 AML. We found an improved outcome for IDH2R172 -mutated AML in the later trials and the data suggests that this may be due to the increased use of allogeneic transplantation to consolidate first remission.

Identification of alpha-enolase as a potential immunogenic molecule during allogeneic transplantation of human adipose-derived mesenchymal stromal cells.

BACKGROUND AIMS: Given their low immunogenicity, immunoregulatory effects and multiple differentiation capacity, mesenchymal stromal cells (MSCs) have the potential to be used for "off-the-shelf" cell therapy to treat various diseases. However, the allorejection of MSCs indicates that they are not fully immune-privileged. In this study, the authors investigated the immunogenicity of human adipose-derived MSCs (Ad-MSCs) and identified potential immunogenic molecules. METHODS: To evaluate the immunogenicity of human Ad-MSCs in vivo, cells were transplanted into humanized mice (hu-mice), then T-cell infiltration and clearance of human Ad-MSCs were observed by immunofluorescence and bioluminescence imaging. One-way mixed lymphocyte reaction and flow cytometry were performed to evaluate the immunogenicity of human Ad-MSCs in vitro. High-throughput T-cell receptor (TCR) repertoire sequencing and mass spectrometry were applied to identified potential immunogenic molecules. RESULTS: The authors observed that allogeneic Ad-MSCs recruited human T cells and caused faster clearance in hu-mice than non-humanized NOD.Cg-Prkdcscid IL2rgtm1Wjl/SzJ (NSG) mice. The proliferation and activation of T cells were significantly enhanced during in vitro co-culture with human Ad-MSCs. In addition, the level of HLA-II expression on human Ad-MSCs was dramatically increased after co-culture with human peripheral blood mononuclear cells (PBMCs). High-throughput sequencing was applied to analyze the TCR repertoire of the Ad-MSC-recruited T cells to identify dominant TCR CDR3 sequences. Using synthesized TCR CDR3 peptides, the authors identified several potential immunogenic candidates, including alpha-enolase (ENO1). The ENO1 expression level of Ad-MSCs significantly increased after co-culture with PBMCs, whereas ENO1 inhibitor (ENOblock) treatment decreased the expression level of ENO1 and Ad-MSC-induced proliferation of T cells. CONCLUSIONS: The authors' findings improve the understanding of the immunogenicity of human Ad-MSCs and provide a theoretical basis for the safe clinical application of allogeneic MSC therapy.