ABSTRACT
Objective: Cytomegalovirus (CMV) DNAemia remains an important complication after hematopoietic stem cell transplantation (HSCT). This study aimed to describe the clinical, virological, treatment-related characteristics, and outcomes of HSCT recipients who developed CMV DNAemia requiring preemptive antiviral therapy at a center where routine letermovir prophylaxis was unavailable.
Materials and Methods: This retrospective cohort study included adult allogeneic or autologous HSCT recipients followed between January 1, 2021, and June 1, 2025. Among 222 screened patients, 46 met the center-specific criteria for preemptive treatment, and 51 CMV DNAemia episodes were evaluated. In allogeneic HSCT recipients, CMV DNA was monitored weekly during the first 100 days after transplantation using quantitative real-time polymerase chain reaction in EDTA-anticoagulated whole-blood samples. Demographic, transplantation-related, virological, treatment, and outcome data were analyzed.
Results: CMV DNAemia requiring treatment occurred in 46 patients (20.7%). The median age was 43 years (IQR, 29-54). The most common underlying diagnoses were acute myeloid leukemia in 13 patients (28.3%) and acute lymphoblastic leukemia in 12 (26.1%). Allogeneic HSCT was performed in 41 patients (89.1%). Forty-four of 51 episodes (86.3%) occurred within the first 100 days after transplantation. The median time to first CMV DNA detection was 43 days (IQR, 36-56 ), and the median viral load at treatment initiation was 2,546 copies/mL (IQR, 1,577-10,245). Intravenous ganciclovir was the initial therapy in 47 episodes (92.2%). The median treatment duration was 18 days (IQR, 10-28) and the median time to PCR negativity was 20 days (IQR, 10–28). Five patients died during follow-up (10.9%).
Conclusion: CMV DNAemia requiring preemptive therapy occurred predominantly during the early post-transplant period. These findings highlight the importance of close, specimen-consistent virological monitoring using a consistent specimen type and assay, together with timely initiation of preemptive therapy based on center-specific thresholds when letermovir prophylaxis is unavailable.
Keywords: Hematopoietic stem cell transplantation, cytomegalovirus, CMV DNAemia, preemptive therapy