Cytomegalovirus reactivation risk after autologous hematopoietic stem cell transplantation: Results of a Tunisian study.

Background: Cytomegalovirus (CMV) reactivation is a potentially severe complication in immunocompromised patients, yet its incidence and impact in recipients of autologous hematopoietic stem cell transplantation (AHSCT) remain insufficiently documented.

Aim: To assess the frequency, timing, and outcomes of CMV reactivation in patients undergoing AHSCT at Aziza Othmana Hospital.

Methods: We conducted a retrospective descriptive study of all patients who underwent AHSCT between January 2022 and December 2024 and had at least one post-transplant plasma viral load (VL) assessment. CMV VL was quantified by real-time polymerase chain reaction using TaqMan probes (GeneProof^®) with a sensitivity threshold of 150 IU/mL.

Results: Among 277 AHSCT recipients, 17 (6.1%) experienced CMV reactivation. Their median age was 43 years, with a sex ratio of 0.46 (male/female). Underlying diseases included large B-cell lymphoma (n = 5), multiple myeloma (n = 3), and Hodgkin's lymphoma (n = 4). The median time to reactivation was 26 days post-transplant (11 days after neutrophil recovery). Median peak VL was 1325 IU/mL (range: 150-641000 IU/mL). Six patients required antiviral therapy (median peak VL: 30150 IU/mL), while 11 had spontaneous resolution (median peak VL: 1320 IU/mL). Two patients died in the context of CMV reactivation.

Conclusion: CMV reactivation occurs in a noteworthy proportion of AHSCT recipients and may lead to severe outcomes. Routine VL monitoring in the early post-transplant period is crucial, and preemptive therapy should be initiated once clinically relevant VL thresholds are reached to prevent progression to CMV disease and associated mortality.