Correlation between fecal calprotectin, ulcerative colitis endoscopic index of severity and clinical outcome in patients with acute severe colitis

Correlation between fecal calprotectin (FC) and endoscopic activity assessed by Ulcerative Colitis Endoscopic Index of Severity (UCEIS) in acute severe colitis (ASC) patients was explored to evaluate the predictive value of FC in clinical outcomes. Seventy-one ASC patients were retrospectively evaluated. FC level within 3 days of colonoscopy was measured with ELISA. Demographic and clinical data, laboratory parameters, and medical therapy were documented, and the endoscopic severity of disease was rated by UCEIS. The end points were the rate of failed corticosteroid therapy, colectomy, and mortality. There was significant correlation between UCEIS and FC level (r=0.729, P<0.001), which was superior to CRP, ESR, and hemoglobin. FC level between endoscopic mild activity (UCEIS, 3-4) and endoscopic moderate activity (UCEIS, 5-6), and endoscopic moderate activity (UCEIS, 5-6) and endoscopic severe activity (UCEIS, 7-8) were significantly different. FC levels were associated with different outcomes (failed corticosteroid therapy or surgery); when FC >1672 µg/g, sensitivity and specificity were 80.2 and 66.7%, respectively, in prediction for colectomy using receiver operating characteristics analysis. The results indicated that FC, as a non-invasive indicator, correlates positively with the UCEIS. Baseline FC level predicts clinical outcomes in ASC patients, which make a timely treatment strategy conversion possible after accurately forecasting the likelihood of failure of intravenous steroid therapy.