Blood stream infection (BSI) and acute GVHD after hematopoietic SCT (HSCT) are associated.

Blood stream infection (BSI) and acute GVHD (aGVHD) are serious complications of hematopoietic SCT (HSCT). We hypothesized that the two events were not independent of one another. We studied (1) associations between BSI and aGVHD; and (2) the impact of BSI and/or aGVHD on death within 100 days after HSCT, using a retrospective cohort analysis. Risk factor analysis was carried out using multivariable Cox proportional hazards analyses. Of 211 patients who underwent allogeneic HSCT from January 2000 to December 2005 (58% of whom underwent reduced intensity transplantation), 82 (39%) developed BSI. In 49 patients (23%), grade (gr) 2-4 aGVHD occurred. Early BSI was independently associated with an increased occurrence of subsequent aGVHD gr 2-4. CMV seropositivity was independently associated with decreased occurrence of aGVHD. aGVHD gr 2-4 independently predicted subsequent first BSI. Both BSI and aGVHD gr 2-4 were significant independent predictors of death within 100 days after HSCT. There is a strong, independent association between BSI and aGVHD. Potential explanations include the elaboration of cytokines during BSI favoring the development of aGVHD and/or the immunosuppressive treatment of aGVHD favoring the development of BSI. Future studies should be directed at the mechanistic investigations of this association.