Clostridium Difficileinfections in patients with AML or MDS undergoing allogeneic hematopoietic stem cell transplantation identify high risk for adverse outcome

Clostridium difficile(CD)infection is the main cause of nosocomial enterocolitis in western countries and in patients undergoing allogeneic hematopoietic stem cell transplantation (alloHCT). Recipients of alloHCT are at high risk for CDinfection but large studies in this population are rare and conflicting results have been reported. We analyzed 727 patients with AML or MDS undergoing alloHCT in our center from 2004 to 2015. Ninety-six patients (13%) had CDinfection and 103 patients (14%) were identified as asymptomatic carriers by screening at admission and once a week during aplasia. Patients with CDinfection had a shorter median overall survival of 8 months (95% CI, 6–36 months) compared with 25 months (95% CI, 17–35 months) for patients without CDinfection, (HR 1.4, p= 0.04). CDpositive patients were less likely to develop acute graft-versus-host disease (aGvHD; HR 0.6, p= 0.004) compared with CD-negative patients, but did not show differences in gastrointestinal aGvHD (HR 0.9, p= 0.5). Symptomatic patients developed gastrointestinal aGvHD (HR 2.5, p= 0.02) more often compared with asymptomatic CD positive patients. This analysis demonstrates a high prevalence for CDinfection in patients undergoing alloHCT. A significant lower overall survival for patients with CDinfection could be demonstrated.