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Increased apoptosis of hematopoietic progenitor cells has been implicated in the pathophysiology of cytopenias associated with myelodysplastic syndromes (MDSs), and inhibition by immunosuppression may account for the success of this treatment in some patients. We examined bone marrow and peripheral blood of 25 patients with chromosomal abnormalities associated with MDS (monosomy 7, trisomy 8, and 5q-) for evidence of apoptosis. When fresh bone marrow was examined, the number of apoptotic and Fas-expressing CD34 cells was increased in patients with trisomy 8, but decreased in monosomy 7, as compared with healthy control donor marrow. Fas expression was increased in the trisomy 8 cells and decreased in the monosomy 7 cells when compared with normal cells from the same patient. Trisomy 8 cells were more likely to express activated caspase-3 than were normal cells. For bone marrow cells cultured with Fas agonist or Fas antagonist, the percentage of cells with trisomy 8 was significantly decreased in most cases after Fas receptor triggering and increased by Fas ligand (Fas-L) antagonist (P < 0.01), suggesting increased Fas susceptibility of cells with trisomy 8. No such changes were seen in cultures of cells with 5q- or monosomy 7. Fas antagonist facilitated the expansion of cells with trisomy 8 only. Cells with trisomy 8 appear to be more susceptible to Fas-mediated apoptosis. Clinical data demonstrating the responsiveness of some patients with trisomy 8 to anti-thymocyte globulin (ATG) and cyclosporine (CsA) would favor an active role of the immune system in this syndrome.

Intensive care physicians may assume the primary care of patients with transplant-associated thrombotic microangiopathy (TA-TMA), an uncommon but potentially critical complication of hematopoietic stem cell transplants (HSCTs) and solid organ transplants. TA-TMA can have a dramatic presentation with multiple organ dysfunction syndrome (MODS) associated with high morbidity and mortality. The typical presenting clinical features are hemolytic anemia, thrombocytopenia, refractory hypertension, proteinuria and worsening renal failure. Intestinal involvement, with abdominal pain, nausea and vomiting, gastrointestinal bleeding, and ascites are also common. Cardiopulmonary involvement may develop from various causes including pulmonary arteriolar hypertension, pleural and pericardial effusions, and diffuse alveolar hemorrhage. Due to other often concurrent complications after HSCT, early diagnosis and effective management of TA-TMA may be challenging. Close collaboration between ICU and transplant physicians, along with other relevant specialists, is needed to best manage these patients. There are currently no approved therapies for the treatment of TA-TMA. Plasma exchange and rituximab are not recommended unless circulating factor H (CFH) antibodies or thrombotic thrombocytopenic purpura (TTP; ADAMTS activity < 10%) are diagnosed or highly suspected. The role of the complement pathway activation in the pathophysiology of TA-TMA has led to the successful use of targeted complement inhibitors, such as eculizumab. However, the relatively larger studies using eculizumab have been mostly conducted in the pediatric population with limited data on the adult population. This review is focused on the role of intensive care physicians to emphasize the clinical approach to patients with suspected TA-TMA and to discuss diagnosis and treatment strategies. [ABSTRACT FROM AUTHOR]

Relapsed or refractory (R/R) acute myeloid leukemia (AML) with FMS-like tyrosine kinase 3 (FLT3) mutations remains a difficult and hard to treat entity. Gilteritinib is a potent oral FLT-3 inhibitor that improves overall survival in R/R AML, but studies are limited in combining gilteritinib with a hypomethylating agent and venetoclax treatment backbone (HMA-VEN-GILT). Here we report our experience with HMA-VEN-GILT for 22 R/R FLT3 AML patients. HMA-VEN-GILT yielded an ORR of 77.3% (17/22), CR 4.5% (1/22), CRi 13.6% (3/22), MLFS 59.1% (13/22). Median follow-up was 10.4 months with a relapse rate of 29.4% (5/17), median time to relapse of 69 days (range 35–298 days), 6-month overall survival of 84%, and median OS of 10.1 months. Additionally, 36.4% (8/22) of patients proceeded to hematopoietic stem cell transplant. In conclusion, HMA-VEN-GILT for the treatment of R/R FLT3 AML is feasible and can be used as a bridge to allogeneic transplantation. [ABSTRACT FROM AUTHOR]

Background: Studies have suggested that acute myeloid leukemia (AML) patients with incomplete hematologic recovery undergoing allogeneic stem cell transplantation (allo‐HSCT) had inferior overall survival (OS). Study Design and Methods: This single‐center, retrospective study of AML patients evaluated the relationship between red blood cell (RBC) and platelet (PLT) transfusion requirements during the first 30 days and long‐term outcomes after allo‐HSCT through multivariate analyses. Results: A total of 692 AML patients received peripheral blood stem cells (89.2%), marrow (5.6%), or umbilical cord (5.2%) from matched related (37.4%), unrelated (49.1%), or haploidentical (8.2%) donors in 2011–2017. Transfusion requirements during the first 30 days for RBC (89.5% transfused, median 3, range 1–18 units) or PLT (98.2% transfused, median 6, range 1–144 units) were variable. By Day 30, 56.7% (95% confidence interval [CI]: 52.8–60.3%) and 86.1% (95% CI: 83.2–88.5%) had achieved RBC and PLT transfusion independence, respectively. Median follow‐up among survivors (n = 307) was 7.1 years (range: 2.7–11.8). Lack of RBC transfusion independence by Day 30 was strongly and independently associated with worse 5‐year OS (39.2% vs. 59.6%, adjusted hazard ratio [HR] 1.83, 95% CI: 1.49–2.25), leukemia‐free survival (35.8% vs. 55.5%, HR = 1.75, 95% CI: 1.43–2.14), and NRM (29.7% vs. 13.7%, HR = 2.05, 95% CI: 1.45–2.89) (p <.001). There was no difference in relapse rates among patients who achieved or did not achieve RBC (p =.34) or PLT (p =.64) transfusion independence. Conclusion: Prolonged RBC dependence predicted worse survival and NRM rates, but not increased relapse. Posttransplant surveillance of such patients should be adjusted with more attention to non‐relapse complications. [ABSTRACT FROM AUTHOR]

This study reports the incidence of chronic graft versus host disease (GvHD) in allogeneic hematopoietic stem cell transplant (alloHCT) recipients who received SARS-CoV2 vaccination. The overall rates of new and worsening chronic GvHD combined were 14%, with median time from vaccination to GVHD being approximately three to four weeks. A majority of the cases were of mild to moderate severity and primarily localized to either the skin, mouth, or joints. Prior chronic GVHD and recent transplant were associated with higher GVHD rates following COVID-19 vaccination. More prospective studies are needed to provide a definitive mechanism for the impact of SARS-CoV2 vaccination on alloHCT patients. [ABSTRACT FROM AUTHOR]

Background: Allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients often require substantial but variable transfusion support.Study Design and Methods: This single-center, retrospective study evaluated the red blood cell (RBC) and platelet (PLT) transfusion data of first-time allo-HSCT recipients transplanted in 2011 to 2017. Multivariate analyses were performed to assess the associations between patient and transplant-related factors and transfusion requirements.Results: The study included 1762 patients who received peripheral blood stem cells (88.2%), marrow (7.0%), or umbilical cord (4.8%) from matched related (38.3%), unrelated (49.2%), or haploidentical (7.8%) donors. Almost all patients required RBCs (88.3%) or PLTs (97.4%) during the first 30 days, with medians of 3 (range, 1-37) RBC and 6 (range, 1-144) PLT units transfused. Fewer patients required RBC (43.8%) or PLT (27.3%) transfusions during Days 31 to 100, but the median (range) numbers of RBC and PLT units remained high at 3 (1-36) and 6 (1-116) among transfused patients. RBC and PLT transfusion independence was reached in medians of 24 (95% confidence interval [CI], 22-26) and 12 (95% CI, 11-12) days, respectively. Haploidentical donor, cord graft, and requiring RBC transfusions in the 10 days before HSCT were the most significant independent factors predictive of increased transfusion requirements. Advanced disease, diagnosis, ABO incompatibility, conditioning intensity, CD34+ cell dose, presence of severe acute graft-vs-host disease, and changes in recommended transfusion triggers were also shown to independently impact transfusion requirements.Conclusions: This study provided for the first time quantitative and comparative transfusion data on a large contemporary cohort of HSCT recipients, including haploidentical and cord graft recipients, and identified factors predictive of increased transfusions. [ABSTRACT FROM AUTHOR]

Background: Triplex vaccine was developed to enhance cytomegalovirus (CMV)-specific T cells and prevent CMV reactivation early after hematopoietic stem cell transplant (HCT).Objective: To determine the safety and efficacy of Triplex.Design: First-in-patient, phase 2 trial. (ClinicalTrials.gov: NCT02506933).Setting: 3 U.S. HCT centers.Participants: 102 CMV-seropositive HCT recipients at high risk for CMV reactivation.Intervention: Intramuscular injections of Triplex or placebo were given on days 28 and 56 after HCT. Triplex is a recombinant attenuated poxvirus (modified vaccinia Ankara) expressing immunodominant CMV antigens.Measurements: The primary outcomes were CMV events (CMV DNA level ≥1250 IU/mL, CMV viremia requiring antiviral treatment, or end-organ disease), nonrelapse mortality, and severe (grade 3 or 4) graft-versus-host disease (GVHD), all evaluated through 100 days after HCT, and grade 3 or 4 adverse events (AEs) within 2 weeks after vaccination that were probably or definitely attributable to injection.Results: A total of 102 patients (51 per group) received the first vaccination, and 91 (89.2%) received both vaccinations (46 Triplex and 45 placebo). Reactivation of CMV occurred in 5 Triplex (9.8%) and 10 placebo (19.6%) recipients (hazard ratio, 0.46 [95% CI, 0.16 to 1.4]; P = 0.075). No Triplex recipient died of nonrelapse causes during the first 100 days or had serious AEs, and no grade 3 or 4 AEs related to vaccination were observed within 2 weeks after vaccination. Incidence of severe acute GVHD after injection was similar between groups (hazard ratio, 1.1 [CI, 0.53 to 2.4]; P = 0.23). Levels of long-lasting, pp65-specific T cells with effector memory phenotype were significantly higher in Triplex than placebo recipients.Limitation: The lower-than-expected incidence of CMV events in the placebo group reduced the power of the trial.Conclusion: No vaccine-associated safety concerns were identified. Triplex elicited and amplified CMV-specific immune responses, and fewer Triplex-vaccinated patients had CMV viremia.Primary Funding Source: National Cancer Institute and Helocyte. [ABSTRACT FROM AUTHOR]

Introduction: Isavuconazole, a triazole antifungal, is an inhibitor of cytochrome P450 3A4, which also metabolizes tacrolimus and sirolimus. In previous studies, isavuconazole administration increased tacrolimus and sirolimus area under the curve values by 2.3‐fold and 1.8‐fold, respectively, in healthy adults and tacrolimus concentration/dose (C/D) ratio by 1.3‐fold in solid organ transplant patients. We aimed to determine the magnitude of effect of isavuconazole administration on tacrolimus and sirolimus C/D ratios in allogeneic hematopoietic stem cell transplant (alloHSCT) patients. Methods: A retrospective, single‐center, single‐arm study in adult alloHSCT patients who received at least 10 days of combination therapy with isavuconazole and tacrolimus and/or sirolimus as inpatients or outpatients was conducted. Tacrolimus and sirolimus trough serum concentrations were measured up to twice weekly for up to 4 weeks. Results: Twenty‐two patients receiving tacrolimus and twenty patients receiving sirolimus met the inclusion criteria. The mean C/D ratio increased from baseline by 1.42‐fold for tacrolimus during week 1 (P = 0.002) and up to 1.56‐fold for sirolimus during week 2 (P = 0.02). For the remaining timepoints, tacrolimus and sirolimus C/D ratios were not statistically significantly different from baseline. Conclusion: In alloHSCT patients, modest increases in tacrolimus and sirolimus C/D ratios from baseline were observed within the first 2 weeks after initiation of isavuconazole. [ABSTRACT FROM AUTHOR]

Attenuated poxvirus modified vaccinia Ankara (MVA) is a useful viral-based vaccine for clinical investigation, because of its excellent safety profile and property of inducing potent immune responses against recombinant (r) antigens. We developed Triplex by constructing an rMVA encoding 3 immunodominant cytomegalovirus (CMV) antigens, which stimulates a host antiviral response: UL83 (pp65), UL123 (IE1-exon4), and UL122 (IE2-exon5). We completed the first clinical evaluation of the Triplex vaccine in 24 healthy adults, with or without immunity to CMV and vaccinia virus (previous DryVax smallpox vaccination). Three escalating dose levels (DL) were administered IM in 8 subjects/DL, with an identical booster injection 28 days later and 1-year follow-up. Vaccinations at all DL were safe with no dose-limiting toxicities. No vaccine-related serious adverse events were documented. Local and systemic reactogenicity was transient and self-limiting. Robust, functional, and durable Triplex-driven expansions of CMV-specific T cells were detected by measuring T-cell surface levels of 4-1BB (CD137), binding to CMV-specific HLA multimers, and interferon-γ production. Marked and durable CMV-specific T-cell responses were also detected in Triplex-vaccinated CMV-seronegatives, and in DryVax-vaccinated subjects. Long-lived memory effector phenotype, associated with viral control during CMV primary infection, was predominantly found on the membrane of CMVspecific and functional T cells, whereas off-target vaccine responses activating memory T cells from the related herpesvirus Epstein-Barr virus remained undetectable. Combined safety and immunogenicity results of MVA in allogeneic hematopoietic stem cell transplant (HCT) recipients and Triplex in healthy adults motivated the initiation of a placebo-controlled multicenter trial of Triplex in HCT patients. [ABSTRACT FROM AUTHOR]

Since Human leukocyte antigen (HLA) and ABO blood group system are inherited independently and with up to 50% of allogeneic hematopoietic cell transplantations (HCT) are performed with donor-recipient ABO incompatibility, recipients are at increased risk for acute and delayed hemolytic reaction and delayed RBC precursors engraftment; i.e. pure RBC aplasia (PRCA). PRCA is a sever consequence of major and bi-directional ABO mismatch after alloHCT, leading to frequent transfusions, iron overload and secondary complications. Risk factors for PRCA after Major ABO incompatibility include; stem cell source, conditioning intensity, and titer of iso-agglutinins. Treatment is mostly supportive with transfusions and growth factors as well as withdrawing immunosuppressive therapy (IS). Targeting recipient immune system with high-dose steroids, DLI, and rituximab have been reported with variable results. Here we report a case series of a novel method of targeting recipient iso-agglutinins-producing B cells by Ibrutinib. We report 3 cases of PRCA refractory to conventional therapy who responded to ibrutinib, a BTK inhibitor targeting recipient B cells to allow engraftment of donor RBCs. Patient, transplant and disease characteristic including prior therapies, time to transfusion independence, and switch of blood group (BG) are summarized in Table 1. First patient's day 30 post-transplant bone marrow biopsy (BMBx) showed complete remission (CR) with full donor chimera, but BG remained O. He developed severe anemia requiring transfusions and Day 100 BMBx showed CR with markedly decreased number of erythroid progenitors. He did not respond to IS withdrawal, prednisone, rituximab or bortezomib. But BMBx 4 weeks after starting ibrutinib showed trilineage hematopoiesis. Second patient remained RBC transfusion dependent post-HCT with Day 100 biopsy showing PRCA and full donor chimera. BG remained O. He developed severe GVHD of skin and eyes after DLI and His PRCA was refractory to multiple lines of therapies but responded to ibrutinib. Third patient underwent HCT for refractory AML with MDS; Anti-A isoagglutinin level pre-HCT was high and patient underwent plasma exchange. Day 30 BMBx showed CR and full donor chimera. Day +73 BMBx showed CR with near absent erythropoiesis. PRCA was refractory to rituximab and responded to ibrutinib. All three patients with PRCA refractory to multiple lines of therapy responded to ibrutinib with median time to transfusion independence of 4 weeks and median time to BG switch of 6 weeks. All patients tolerated therapy well. Our experience at City of Hope shows that ibrutinib could offer a safe and efficacious treatment option for cases of refractory PRCA. Prospective studies are needed to assess if early therapy with ibrutinib could reduce the morbidity resulting from frequent transfusions, and GVHD complications. [ABSTRACT FROM AUTHOR]