LATE INFECTIONS AFTER ALLOGENEIC BONE-MARROW TRANSPLANTATION - COMPARISON OF INCIDENCE IN RELATED AND UNRELATED DONOR TRANSPLANT RECIPIENTS

Infectious complications are a major cause of morbidity and mortality after allogeneic bone marrow transplantation (BMT). We have evaluated the incidence of late infections (beyond day +50) in recipients of rel ated (RD) and unrelated donor (URD) allogeneic BMI, factors associated with increased risks of infection, and the impact of the late infecti ons on survival. Between 1989 and 1991, 249 patients received an RD (n = 151) or URD (n = 98) allogeneic BMT at the University of Minnesota and all late infections were investigated. Three hundred sixty-seven l ate infectious events developed in 162 patients between 50 days and 2 years after BMT. The incidence of any late infection was greater in UR D versus RD recipients (84.7% v 68.2%, respectively; P = .009). In mul tivariate analysis, advanced graft-versus-host disease (GVHD) was sign ificantly associated with late infections. The effect of GVHD was appa rent only in RD recipients (relative risk [RR], 2.29; P = .003), where as URD recipients, with or without GVHD, had more late infections comp ared with RD recipients without GVHD. Multivariate analysis showed tha t late posttransplantation infections were the dominant independent fa ctor associated with increased nonrelapse mortality (RR, 5.5; P = .000 1), resulting in improved 3-year survival for RD versus URD recipients (49.9% +/- 8% v 34.4% +/- 10%; P = .004). In this study, we observed that late infections are more frequent in URD recipients, resulting in substantially higher nonrelapse mortality. This prolonged period of i ncreased infectious risk in URD recipients suggests the need for aggre ssive surveillance and therapy of late infections and perhaps prolonge d antibiotic prophylaxis for all URD BMT recipients. (C) 1995 by The A merican Society of Hematology.