Rapid Fecal Calprotectin Test and Symptom Index in Monitoring the Disease Activity in Colonic Inflammatory Bowel Disease

Fecal calprotectin is a reliable surrogate marker for inflammatory activity in inflammatory bowel disease (IBD). For the noninvasive monitoring of the activity of colonic inflammation, we validated a symptom index suitable for ulcerative colitis and colonic Crohn's disease. By combining the symptom index with a rapid semi-quantitative calprotectin test, we constructed a new activity index based on the highest AUCs, using histological remission as a reference. We also evaluated the correlation of the patient-reported influence of the IBD in the daily life, measured by a VAS, with the inflammation activity. The disease activity of 72 patients with IBD of the colon was determined by endoscopic activity scores (SES-CD/UCEIS). The patients provided stool samples for determination of calprotectin and filled in a questionnaire about their symptoms during the last week. The results of the symptom index demonstrated a statistically significant correlation with the rapid calprotectin test, histological inflammation activity, and the VAS. No correlations were found between the VAS and calprotectin or the histological inflammation activity. The sensitivity of the combination index to detect active inflammation was slightly superior to fecal calprotectin alone. The new symptom index and the combination index are simple, noninvasive means for distinguishing remission from active inflammation in colonic IBD. With the VAS, we can pick up patients who need psychosocial support because of the disease burden, even if their IBD is in remission.