Correlation and concordance measures between clinical, endoscopic and histological scores activity in Crohn's disease under treatment.

Our aim was to evaluate the correlation and concordance measures between clinical, endoscopic and histologic remission in Crohn's disease (CD) under treatment. Twenty-four patients with CD under treatment were included in a prospective consecutive cross-sectional study from January to September 2018. Clinical activity was assessed by Crohn's Disease Activity Index (CDAI). All of the patients were submitted an ileocolonoscopy with biopsy and classified by Simple Endoscopic Score (SES-CD). Histologic activity was assessed by Global Histologic Activity Score (GHAS) modified. Remission was considered with CDAI <150; SES-CD ≤2 and GHAS ≤4. Clinical remission was established in 53%, however, only 50% had mucosal healing (MH) and 70% had inflammatory histologic activity. Correlation between endoscopic and histological measures was strong and positive (σ = 0.73,  < .0003). The concordance remission agreement between SES-CD and GHAS was weak with (κ) = 0.3 (IC 95%: -0.09; 0.69). The greatest disparity arose when clinical activity (CDAI) was compared with histological measures (σ = 0.20,  = .45), (κ) = 0.26 (IC = -0.03; 0.56). The score SES-CD correlates well with histological score GHAS in CD under treatment, however, there is low concordance between both mainly in patients with anti-TNFs treatment. CDAI score had low correlation and concordance with histological score GHAS. In this sample, patients under treatment and without symptoms had low MH and histologic healing.