Assessing the significance of cytomegalovirus reactivation in recipients of allogeneic hematopoietic stem cell transplantation: a cohort study.

Cytomegalovirus (CMV) infection increases morbidity in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. Despite advancements in prevention and treatment, CMV reactivation remains a considerable concern following allo-HSCT. In this study, we aimed to evaluate the impact of CMV reactivation in allo-HSCT recipients on clinical outcomes and patient survival, as well as to identify the risk factors associated with CMV reactivation. This retrospective observational cohort study included data from 67 transplantations performed between 2019 and 2022 at a private hospital in Belo Horizonte, Brazil. Clinical, laboratory, and procedural data were collected. The median age of the patients was 47.0 years, and 52.2% of them were women. The most frequent indication for allo-HSCT was acute myeloid leukemia (28.4%), followed by myelodysplastic syndrome (16.4%). CMV reactivation occurred in 62.7% of the recipients, and the median time to CMV reactivation was 32.5 days. Six patients (9.0%) presented with CMV end-organ disease (83.3% were free of systemic disease); however, when present, gastrointestinal involvement was the most common disease (4.5%). In the multivariate analysis, the risk factors for CMV reactivation included acute lymphoblastic leukemia (P=0.006), mismatched human leukocyte antigen (HLA)-unrelated donors (P=0.002), and graft-versus-host disease (P=0.024). One-year overall survival was 57.7%. However, CMV reactivation was not significantly associated with mortality after controlling for confounding factors. CMV reactivation remains a common complication following allo-HSCT, with leukemia type, donor type, and graft-versus-host disease affecting the risk of disease recurrence. No direct correlation was observed between CMV recurrence and increased mortality or patient survival.