Hemato

Introduction: Ropeginterferon alfa-2b is an emerging treatment for polycythemia vera, with growing interest in its application for essential thrombocythemia and early myelofibrosis due to its extended dosing intervals and favorable tolerability profile. However, real-world evidence regarding its dosing strategies and titration practices remains limited. Objective: This study examined seven younger patients, all under 60 years of age, who were treated with ropeginterferon alfa-2b. Materials and Methods: This study is a retrospective medical records review of consecutive patients from seven hospitals. Treatment was initiated at a dose of 250 micrograms, with a maintenance dose of 500 micrograms. Results: The regimen demonstrated good safety and tolerability in this real-world setting. Hematological responses were observed, along with a meaningful reduction in JAK2V617F variant allele frequency across the patient cohort. Conclusions: These findings show that the use of high-initial-dose accelerated titration (HIDAT) regimen of ropeginterferon alfa-2b is a safe and effective treatment option for younger patients with myeloproliferative neoplasms.

Background: The emergence of therapy-related myelodysplastic syndrome (t-MN) after autologous stem cell transplantation (ASCT) is well documented. However, with the growing use of chimeric antigen receptor (CAR) T-cell therapy for relapsed/refractory B-cell malignancies, concerns about secondary myeloid neoplasms, particularly MN, have arisen. The mechanisms and cytogenetic features associated with post-CAR-T MN, especially chromosome 7 abnormalities, remain underexplored. Objectives: To compare the incidence, timing, and cytogenetic characteristics of MN developing after CAR-T-cell therapy versus ASCT, and to evaluate the potential association between CAR-T therapy, persistent cytopenias, and these specific alterations. Study Design: This was a retrospective, single-center study of 275 patients with B-cell malignancies treated between 2015 and 2024 at Hospital Universitario Central de Asturias (Spain). Of these, 259 patients underwent ASCT and 16 received CAR-T-cell therapy (axicabtageneciloleucel n = 13, tisagenlecleucel n = 2, brexucabtageneautoleucel n = 1). Clinical, cytogenetic, and laboratory data were collected and analyzed. Incidence rates were compared using Fisher’s exact test, and time-to-event outcomes was evaluated using the Mann–Whitney U test (given the small number of events). Statistical significance was set at p < 0.05. Results: Myeloid neoplasms were diagnosed in 3 of 259 ASCT patients (1.15%) and in 2 of 16 CAR-T-cell patients (12.5%) (p = 0.03). The median time to myeloid neoplasm diagnosis was numerically shorter in the CAR-T group (15.5 vs. 69 months, p = 0.096). All post-CAR-T cases presented persistent cytopenias and cytokine release syndrome (CRS). Cytogenetic analyses revealed de novo monosomy 7 and 7q deletion in both CAR-T-related cases, whereas no chromosome 7 abnormalities were detected in ASCT-related cases. Pre-treatment samples did not show these abnormalities, although limitations in the sensitivity of the assays preclude the definitive exclusion of minor pre-existing clones. Both affected CAR-T patients had prolonged CAR-T cell persistence and required transfusional support due to hematologic toxicity. One patient was diagnosed with high-risk MN with 5q and 7q deletion and the other with Clonal Cytopenia of Uncertain Significance (CCUS) with monosomy 7. Conclusions: CAR-T-cell therapy was associated with a significantly higher and earlier incidence of myeloid neoplasms compared to ASCT in this cohort. The development of post-CAR-T myeloid neoplasm was characterized by persistent cytopenias, prolonged CAR-T cell persistence, and de novo chromosome 7 alterations. While the small sample size necessitates cautious interpretation, these findings may suggest a distinct pathogenesis potentially linked to inflammation, immune toxicity, or the expansion of pre-existing clones. This highlights the need for long-term hematologic monitoring and evaluation for clonal hematopoiesis prior to CAR-T-cell therapy, especially in heavily pretreated patients.

Background/Objectives: Understanding blood group antigen distribution is essential for transfusion safety and preventing alloimmunization in transfused patients. The ABO, RH1, and Kell blood group systems are among the most clinically significant due to their high immunogenic potential and their role in hemolytic transfusion reactions and hemolytic disease of the newborn. Despite their clinical significance, data on the phenotypic frequency of these samples in southern Chile are limited. This study aimed to identify the distribution of ABO, RH1, and Kell blood group systems among blood donors at the Centro de Sangre Concepción, adding regional data to the national transfusion medicine records. Methods: A retrospective, descriptive analysis was conducted using data from 59,318 blood donations collected in 2024 by the Concepción Blood Center, part of the Southern Transfusion Medicine Macronetwork in Chile. Blood typing for the ABO, RH1, and Kell antigen (KEL1) typing was performed in accordance with national regulations established by the Ministry of Health (MINSAL). Results: Blood group O was the most frequent (61.3%), followed by A (27.8%), B (9.0%), and AB (1.9%). RH1 positivity was observed in 94.47% of donors, and Kell positivity in 4.24%. The distribution of Kell phenotypes was comparable between men (4.38%) and women (4.11%), with the highest frequency in donors aged 27–52 years. Conclusions: The phenotypic distribution observed reflects national patterns and shows the genetic makeup of southern Chile. The low but important prevalence of Kell-positive donors emphasizes the need for systematic Kell antigen screening to prevent alloimmunization and improve transfusion safety.