Clinical Research: Supportive CareRisk Factors and Outcomes of Infections by Multidrug-Resistant Gram-Negative Bacteria in Patients Undergoing Hematopoietic Stem Cell Transplantation

•We reported the results of a 3-year surveillance program of infections by multidrug-resistant gram-negative (MDR GN) bacteria in a transplant unit.•Cumulative incidence of MDR GN infections was 10.5%.•Allogeneic transplant and colonization by MDR GN bacteria at admission to the transplant unit were significantly associated with an increased risk of infection.•Patients who proceeded to allogeneic transplant and developed MDR GN infections had a significantly higher TRM and a poorer OS compared with patients without MDR infections.•The risk-to-benefit ratio of performing an allogeneic transplant could be carefully evaluated in patients colonized with MDR GN bacteria.

The objective of this study was to determine risk factors and outcomes of infections by multidrug-resistant gram-negative (MDR GN) bacteria in 241 recipients of hematopoietic stem cell transplantation (HSCT). The cumulative incidence of infections was 10.5% (95% CI, 12.0% to 25.8%), with 57% of infections occurring during the period of severe neutropenia (neutrophil count < .1 × 106/L). In multivariate analysis, allogeneic transplant and colonization with MDR GN bacteria at admission to the transplant unit were significantly associated with an increased risk of infection. Although we observed neither transplant-related mortality (TRM) nor deaths due to infections by MDR GN bacteria after autologous transplant, in the allogeneic setting a significant difference was reported in terms of overall survival (OS) and TRM between patients who developed infections and those who did not (1-year OS, 39% versus 68%; 1-year TRM, 42% versus 19%). In multivariate analysis, refractory disease and development of grades III to IV graft-versus-host disease (GVHD) were factors that affected both TRM and OS, whereas occurrence of infections by MDR GN pathogens significantly reduced OS. We conclude that eligibility to allogeneic HSCT in MDR GN bacteria carriers should be carefully evaluated together with all other factors that independently influence outcome (disease status, donor, and GVHD risk).