to compare non-invasive markers like fecal calprotectin, c-reactive protein, crohn’s disease activity index (CDAI), total leukocyte count with the simple endoscopic score in crohn’s disease in assessing activity of crohn’s disease
Ashfaq Ahmad, Waseem Raja, Sunil K Mathai, Benoy Sebastian
Introduction: The diagnosis of CD is established with clinical, endoscopic, histological and imaging studies of the bowel. Various markers have been proposed to objectively evaluate disease activity, but sensitivity and specificity have been a concern for each. A combination of biomarkers may be the most useful for prediction or confirmation of clinical disease activity and endoscopically visible inflammation. Aims & Objective: The aim of study was to compare non-invasive markers like fecal calprotectin, C-reactive protein (CRP), Erythrocyte sedimentation rate (ESR), Crohn’s disease activity index (CDAI), blood leukocytes count with the simple endoscopic score in assessing activity of Crohn’s disease (CD). Material & Methods: All Crohn’s patients undergoing ileocolonoscopy were enrolled in our study. The sample size calculated for the present study was 45 patients. SES-CD score was calculated after ileocolonoscopy, Fecal calprotectin test, Blood sample for leukocyte count and CRP was done in all patients, CDAI is calculated. All laboratory parameters were correlated with SES-CD. The data was analysed by IBM SPSS Statistics 20 version. Results: Out of 45 patients, 28 were male.. Mean age of patients were 35.08 years, and median duration of disease was 65.71 months. According to Montreal classification, the distribution was age at onset A1:A2:A3 0:30:15, location of disease L1:L2:L3 11:05:29, behaviour of disease B1:B2:B3 26:07:02. According to SES-CD score patients was divided into four groups. Inactive subgroup (SES-CD score <3) were 6, mild activity (SES-CD score 4-10) was observed in 10 patients. Moderate activity (SES-CD score 11-19) was seen in 20 patients. 9 patients had severe activity (SES-CD score >20). Fecal calprotectin was positive in 3/6 patients in inactive subgroup, 10/10 in mild subgroup,20/20 in moderate subgroup,9/9 in severe subgroup. C-reactive protein was positive in 3 cases of mild subgroup of SES-CD, 18 cases of moderate subgroup and 9 cases of severe subgroup of SES-CD. CRP was negative in inactive subgroup. Scatter plot demonstrates the positive correlation with SES-CD score.Mean CRP in inactive subgroup was 3.66±0.81, mild 5.7±2.86, moderate 75.1±32.41, severe 176.22±26.29 which is statistically significant (<0.001). CRP is helpful in differentiating mild activity from moderate activity, moderate activity from severe activity; however it is not helpful in discriminating inactive from mild disease activity. ESR was positive in 6 patients of moderate subgroup and 8 of severe subgroup of patients which is statistically significant (<0.001), however it is negative in inactive and mild subgroup of patients. Total leucocyte count was positive in 4/20 in moderate subgroup, 8/9 in severe subgroup which is statistically significant (<0.001). Total leucocyte count was negative in inactive and mild subgroup of patients. TLC could neither discriminate inactive from mild nor mild from moderate endoscopic activity. CDAI was positive in 9/45 patients which is statistically significant (<0.001) in discriminating moderate from severe activity. Conclusions: Fecal Calprotectin is superior to all non-invasive tests for identifying inactive disease activity. It has closest correlation to SES-CD. Fecal calprotectin was positive in 93.3% of patients which is highest for any non –invasive marker. CRP helps in differentiating mildly active from moderate and severely active disease. ESR helps in differentiating moderate active from severely active disease. CDAI is less effective in identifying the disease activity.