5-Aminosalicylic Acid (5-ASA) Usage During C. difficile Infection (CDI) Is Associated with Decreased ICU Admission and Improved Long-term Outcomes

Abstract

Introduction: Pts with Inflammatory bowel disease (IBD) are at increased risk for CDI. 5-ASA effects on the small bowel and colonic mucosa may be protective against CDI. We hypothesize that pts with CDI who are chronically on a 5-ASA have better outcomes compared with those not on a 5-ASA. Methods: We identified consecutive pts with a +C. difficile toxin assay and symptomatic diarrhea at Yale-New Haven Hospital between 4/10 and 5/14. For each patient, we recorded demographics, medical co-morbidities, lab data at diagnosis, treatments and outcomes (ICU admission, 90-day readmission, 6 and 12-month mortality). Pts were grouped into those on a 5-ASA (CDI+5-ASA) and those not on a 5-ASA (CDI-5-ASA) and subsequently compared (SPSS 23.0). Results: We identified 796 patients with CDI; 19 (3.0%) were receiving a 5-ASA and 777 (97.0%) were not. CDI+5-ASA were younger (54.4±24.2, 65.1±17.9 years, p=0.012) with a lower Charlson comorbidity score (1.94±1.8, 3.08±2.4, p=0.04). No other differences in demographics were observed. At the time of diagnosis, CDI+5-ASA were more likely to have IBD (100% vs. 2.1%, p < 0.001) without differences in biologic (10.5% vs. 20.0%, p=0.63) or Immuno-modulator use (15.8%, 0%, p=0.24). Vital signs and serologies at presentation were similar among the cohorts, with a trend for increased CT abdomen (42.1%, 22.9%, p=0.06) in CDI+5-ASA. Treatment patterns did not vary among the cohorts. CDI+5-ASA were less likely to require ICU admission at diagnosis (5.3%, 32.1%, p=0.01) or during hospitalization (5.3%, 38%, p=0.003). In a logistic regression, controlling for Charlson co-morbidity score and age, CDI+5-ASA were less likely to be admitted to the ICU at diagnosis (OR, 0.132; CI, 0.02-1.0, p=0.05), require any ICU admission during hospitalization (OR, 0.11; CI, 0.01-0.8, p=0.03) or be readmitted within 90 days (OR, 0.31; CI, 0.10-0.97, p=0.044). CDI+5-ASA were less likely to be readmitted within 90 days (21.1%, 42.2%, p=0.006) or die within 6 (0%, 3.3%, p=0.02) or 12-months (0%, 30.2%, p=0.01). Conclusion: CDI+5-ASA have less severe outcomes compared with CDI-5-ASA independent of age and co-morbidities. The lower ICU requirement and mortality in CDI+5-ASA may be due to 5-ASA effect on the host microbiome, reduction of colonic inflammatory response or direct inhibitory effects on C. difficile toxins.