Impact of Donor Age, Sex, and Abo Compatibility on Outcomes After Matched Unrelated Donor Hematopoietic Stem Cell Transplantation for Acute Leukemia: A Retrospective Single-Center Cohort Study Publisher



Kheiri G ; Mashayekhi M ; Saeidi S ; Salemi F ; Dehaghi M O ; Tavakoli S ; Ghavamzadeh S ; Mohammadi S ; Babakhani D ; Barkhordar M
Source: Health Science Reports Published:2026

Abstract

Background and Aims: Donor-related factors, including donor age, sex, and ABO compatibility, remain clinically relevant considerations in matched unrelated donor hematopoietic stem cell transplantation (MUD-HSCT). However, their independent contribution to post-transplant outcomes in contemporary practice is difficult to define, particularly in smaller institutional cohorts. We evaluated the association of selected donor characteristics with transplant outcomes in adult patients with acute leukemia undergoing MUD-HSCT. Methods: This retrospective single-center cohort study included 85 consecutive patients with acute myeloid leukemia (AML; n = 45) or acute lymphoblastic leukemia (ALL; n = 40) who underwent first MUD-HSCT between 2015 and 2022. Overall survival (OS), disease-free survival (DFS), and graft-versus-host disease-free/relapse-free survival (GRFS) were analyzed using Kaplan–Meier estimates and univariable Cox proportional-hazards models. Relapse and non-relapse mortality (NRM) were assessed using competing-risk methods. Analyzes were restricted to univariable models because of limited event numbers. Results: The median recipient age was 27 years (range, 14–61), and the median donor age was 30 years (range, 14–73). Based on the Disease Risk Index recorded in the institutional database, 54 patients (63.5%) had high-risk disease and 31 (36.5%) had standard-risk disease. Donor age ≥ 30 years was not significantly associated with OS, DFS, GRFS, relapse, or NRM in either AML or ALL. ABO compatibility was also not significantly associated with these outcomes. In ALL, female donor sex was associated with inferior GRFS compared with male donor sex (HR, 3.21; 95% CI, 1.44–7.16; p = 0.004), whereas no significant association with OS or DFS was observed. No significant donor sex-related association was detected in AML. Conclusion: In this single-center cohort of patients undergoing MUD-HSCT for acute leukemia, donor age and ABO compatibility were not statistically associated with major transplant outcomes. Female donor sex was associated with inferior GRFS in ALL, but this finding should be interpreted cautiously given the limited subgroup size, low event numbers, and absence of multivariable adjustment. Larger multicenter studies incorporating disease biology, MRD status, and transplant-related covariates are needed to validate these observations. © 2026 The Author(s). Health Science Reports published by Wiley Periodicals LLC.