Antibacterial Prophylaxis before Autologous Hematopoietic Stem Cell Transplant and Risk of Clostridium Difficile-Associated Diarrhea

Clostridium difficile is the leading cause of infectious diarrhea among hospitalized patients and is a major concern for patients undergoing hematopoietic cell transplantation (HCT). Risk factors and the natural history of C. difficile infection (CDI) are poorly understood in this population. The objective of this study is to determine the incidence of CDI during and after auto-HCT and to identify risk factors for the development of CDI including diagnosis. Methods: We performed a retrospective study to describe the epidemiology, timing, and risk factors for CDI among adult patients who received autologous HCTs at our center from January 2007 through December 2018. CDI was defined any stool C. difficile toxin positive test after the day of stem cell infusion. Results: Overall, 516 patients received auto-HCT for Multiple Myeloma (MM) and lymphoma during the study period, 271 and 245, respectively. Overall, the 1-year incidence of CDI was 6.2% (n=30). Seventy two percent of the patients who developed CDI had lymphoma and 18% had MM (p=0.001). The median time from day of stem cell infusion to CDI positive test was 5 days (range 1:228) for lymphoma pts and 10.5 days (rage 4-42) for MM pts (p-value: 0.269). Median age for MM pts was 54 years and 58 for lymphoma pts (p-value: 0.328). Given the different patient population and therapy history between MM and lymphoma patients, we limit our analysis to MM subset to assess the potential risk factors impacting CDI occurrence after transplant. Previous antibiotic use (i.e., other than acyclovir), co-morbidities and other variables were assessed (Figure-1). Among MM patients, prophylactic antibiotics or corticosteroid use before transplant were not statistically significant associated with CDI. Twenty seven percent of patients with CDI had history of previous CDI vs. only 5% in no-CDI cohort (p-value: 0.001). Lymphopenia was present in 54% of CDI cohort at diagnosis whereas 29% of no-CDI cohort had lymphopenia (p-value: 0.031). Furthermore, chronic kidney disease (CKD) was associated significantly with CDI occurrence (p-value: 0.001). Conclusion: These results suggest lymphoma patients undergoing auto-HCT are at higher risk of developing CDI than MM patients which is different from older reports (Alonso, et al. Clinical infectious diseases. 2012). Our data illustrates pre-transplant prophylactic antibiotics or corticosteroid use is not associated with higher CDI incidence after transplant for MM patients undergoing transplant, while history of previous CDI in the year before transplant, lymphopenia and CKD may be significant predictors. This findings merits further confirmations in larger series.