Incidence, Risk Factors, and Outcomes of Viral Reactivations in Alternative Donor Hematopoietic Stem Cell Transplants

Viral reactivations frequently complicate unrelated donor (UD) and haploidentical (HI) stem cell transplants (SCTs). We analyzed incidence, risk factors, and outcomes of viral reactivations in alternative donor transplants at our center.

This retrospective study included all cases of UD or HI transplants performed between January 1, 2009 and February 29, 2020. We identified 196 viral reactivations in 87 patients in this cohort.

The incidence of cytomegalovirus (CMV), Epstein-Barr virus (EBV), and adenovirus (ADV) reactivation was 80.5, 36.7, and 26%, respectively. CMV colitis was observed in six patients (8.5%). Acute graft-versus-host disease (GVHD) was a significant risk factor for CMV reactivation. Four patients (5%) developed ADV disease requiring treatment with cidofovir. Anti-thymocyte globulin use and acute GVHD were significant risk factors for ADV reactivation. Mild hemorrhagic cystitis due to BK virus was observed in 32% patients. However, significant cystitis requiring intervention was seen in only four patients. Two patients developed EBV-related lymphoproliferative disorder and one patient experienced human herpes virus 6-related graft failure. Viral reactivations had no impact on overall survival.

The incidence of CMV reactivation in alternative donor HSCTs is high (80%) in the Indian population. Acute GVHD is a significant risk factor for CMV, ADV, or EBV reactivation. The rates of ADV, BK virus, and EBV reactivation requiring intervention are low. Better prophylactic strategies are required to prevent CMV reactivation in alternative donor transplants.