Clostridium difficile colitis: Increasing incidence, risk factors, and outcomes in solid organ transplant recipients

Background: Clostridium difficile-associated diarrhea (CDAD) is an increasingly important diagnosis in solid organ transplant recipients, with rising incidence and mortality. We describe the incidence, risk factors, and outcomes of colectomy for CDAD after solid organ transplantation. Methods: Patients with CDAD were identified from a prospective transplant database. Complicated Clostridium difficile colitis (CCDC) was defined as CDAD associated with graft loss, total colectomy, or death. Results: From 1999 to 2010, we performed solid organ transplants for 1331 recipients at our institution. The incidence of CDAD was 12.4% (165 patients); it increased from 4.5% (1999) to 21.1% (2005) and finally 9.5% (2010). The peak frequency of CDAD was between 6 and 10 days posttransplantation. Age more than 55 years (hazard ratio [HR]: 1.47, 95% confidence interval [CI]=1.16-1.81), induction with antithymocyte globulin (HR: 1.43, 95% CI=1.075-1.94), and transplant other than kidney alone (liver, heart, pancreas, or combined kidney organ) (HR: 1.41, 95% CI=1.05-1.92) were significant independent risk factors for CDAD. CCDC occurred in 15.8% of CDAD cases. Independent predictors of CCDC were white blood cell count more than 25,000/μL (HR: 1.08, 95% CI=1.025-1.15) and evidence of pancolitis on computed tomography scan (HR: 2.52, 95% CI=1.195-5.35). Six patients with CCDC underwent colectomy with 83% patient survival and 20% graft loss. Of the medically treated patients with CCDC (n=20), the patient survival was 35% with 100% graft loss. Conclusions: We have identified significant risk factors for CDAD and predictors of progression to CCDC. Furthermore, we found that colectomy can be performed with excellent survival in selected patients.