Predictive accuracy of fecal calprotectin in assessing clinical activity and disease severity in patients with Ulcerative Colitis and Crohn's disease.

Abstract

Background: Inflammatory bowel disease (IBD) is an idiopathic disorder characterized by repeated relapses and remissions. Endoscopy, the gold standard for diagnosis and monitoring of these patients is time consuming, expensive, and invasive. Hence, faecal calprotectin (FCP) has been suggested as marker to determine the degree of intestinal inflammation and predict relapse in IBD.

Objective: To use FCP as a predictor of clinical activity and endoscopic severity in IBD patients in a tertiary care hospital in Southern India.

Methods: Study subjects underwent clinical examination, endoscopy, blood tests and stool FCP. For Endoscopic activity simple endoscopic score for Crohn's disease (SES-CD) and Ulcerative Colitis endoscopic index of severity (UCEIS) scores were used, and clinical activity was assessed by Crohn's disease activity index (CDAI) and simple clinical colitis index (SCCAI) for CD and UC respectively. At six months, blood, and stool FCP test were repeated which were compared with endoscopic and clinical activity indices.

Results: The number of males was higher in both CD (13/8) and UC (19/14). At first visit and follow up, CDAI and FCP were positively correlated (r-0.689, p- 0.016) (r- 0.425, p-value < 0.05). In CD, the sensitivity and specificity of FCP in detecting active disease and remission were 93.8% and 80% respectively (AUC-0.869). At follow up, the sensitivity and specificity were 80% and 93.3% respectively (AUC-0.867). In patients with UC, SCCAI score and FCP levels positively correlated (r-0.231/0.387, p-value 0.001/0.001) at both the first and follow up visits. The sensitivity of FCP in detecting UC in active and remission states was 92.6% whereas the specificity was 83.3%. AUC was 0.88. At the time of follow up, the sensitivity of FCP in detecting UC in active and remission states was 89.9% whereas the specificity was 87.0% and AUC was 0.879.

Conclusion: This study confirmed that FCP level shows strong association with clinical and endoscopic activity indices in patients of IBD. Therefore, FCP levels could be used as a surrogate marker for monitoring mucosal status as well as predicting endoscopic remission in IBD patients.