Timepoints of vancomycin-resistant Enterococcus colonization predict outcomes of acute myeloid leukemia patients undergoing allogeneic hematopoietic cell transplantation

Background: In hematology and oncology, in particular in the setting of allogeneic hematopoietic stem cell transplantation (allo-HSCT), vancomycin-resistant Enterococcus spp. (VRE) colonization rates are high due to previous hospital stays and preceding antibiotic treatment and colonized patients have a lower overall survival (OS).

Objective: We reanalyzed our previously published cohort, to unravel which colonization timepoints before and during allo-HSCT might be predictive for the subsequent outcome.

Patients and methods: We report about 268 patients with acute myeloid leukemia receiving an allo-HSCT between 2006 and 2016.

Results: We identified 129 never-colonized patients, 15 previously colonized patients (positive only before admission for allo-HSCT), 41 persistently colonized patients (positive before and at admission for allo-HSCT), and 83 newly colonized patients (positive only during allo-HSCT). Persistently and newly colonized patients had a worse 60 months OS due to increased incidence of non-relapse-related mortality (NRM) than never-colonized patients (OS: never-colonized: 61.0% vs persistently colonized: 43.5%; P = 0.023 vs newly colonized: 45.6%; P = 0.046). In contrast, OS and NRM of never-colonized and previously colonized patients as well as between persistently and newly colonized patients were similar.

Conclusion: Patients can lose their VRE colonization status and acquisition of VRE during inpatient stay for allo-HSCT decreases survival to a similar extend as persistent colonization.