Donor cytomegalovirus seropositivity and the risk of leukemic relapse after reduced‐intensity transplants

Abstract

Despite effective preemptive and prophylactic therapeutic strategies, cytomegalovirus (CMV) seropositivity of either recipient and/or donor still remains an important parameter for outcome even after reduced-intensity allogeneic stem cell transplantation (SCT). Whether CMV seropositivity of the donor might have an impact on leukemic relapse is unknown. Between June 1999 and February 2004 48 patients ineligible for conventional allotransplantation underwent reduced-intensity transplants at our institution. Twenty-seven (56%) patients had a CMV-seropositive donor. While donor CMV seropositivity had no effect on overall survival, having a CMV-seropositive donor was associated with a significantly lower risk for relapse (20% vs. 52%, P = 0.02). The beneficial effect of a CMV-seropositive donor, however, was offset by a higher transplant-related mortality (42% vs. 19% in patients with a CMV-seronegative donor, P = 0.2). Donor CMV serostatus had no effect on the incidence of CMV infection/disease, and acute or chronic graft-vs.-host disease. Overall, 27 patients died during the observation period. Causes of death in patients with a CMV-seropositive donor were primarily transplant-related (11 vs. 4 in patients with CMV-seronegative donors), whereas leukemic relapse was the leading cause of death in patients with a CMV-seronegative donor (8 vs. 4 in patients with a CMV-seropositive donor, P = 0.038, chi-squared test). Multivariate Cox regression analysis showed risk category by the underlying disease and donor CMV seropositivity to be significant predictors of leukemic relapse following reduced-intensity transplants. These preliminary results suggest a possible role of donor CMV serostatus on the risk of relapse following reduced-intensity allogeneic SCT.