Which endoscopic severity assessment tool correlates best with non-invasive Crohn’s disease activity parameters?

Aims Although there are several scores for endoscopic severity assessment in Crohn’s disease (CD), there is conflicting and scarce information regarding their agreement and relationship with laboratory non-invasive parameters, namely C-reactive protein (CRP) and fecal calprotectin (FC). We aimed to investigate the agreement between the Simple Endoscopic Score for Crohn’s Disease (SES-CD), Modified Multiplier SES-CD (MM-SES-CD), and the recently suggested Toronto Inflammatory Bowel Disease Global Endoscopic Reporting (TIGER) score and their correlation with CRP and FC in CD.

Methods Retrospective cohort-study including all ileocolonoscopies performed in adult CD patients between January 2021 and July 2023 with CRP (mg/dL) and FC (ug/g) collected within one month. Patients with previous intestinal surgery or inadequate bowel preparation were excluded. Agreement between SES-CD (active disease>3), MM-SES-CD (active disease≥14), and TIGER scores (active disease≥100) was determined using Kappa statistics (k) and each value was correlated with laboratorial biomarkers using Spearman's correlation coefficients (rho).

Results A total of 312 ileocolonoscopies from 246 CD patients were included, most females (52.9%) with a mean age of 42±14 years old. According to Montreal Classification, most patients had A2 (71.2%), L1 (47.8%) and B1 (69.6%) disease. Median SES-CD, MM-SES-CD, TIGER scores were 3, 12, and 3 points, respectively. The mean/median value of CRP was 2.9 mg/dL, while mean FC value was 243 ug/g. There was an excellent, strong, and moderate agreement between SES-CD and MM-SES-CD (k=0.929, P<0.001), SES-CD and TIGER (k=0.682, P<0.001), and MM-SES-CD and TIGER score (k=0.504, P<0.001), respectively. There was a fair correlation between SES-CD (rho=0.412), MM-SES-CD (rho=0.423), TIGER score (rho=0.430) and CRP (P<0.001). SES-CD (rho=0.563), MM-SES-CD (rho=0.540) had a fair correlation and TIGER score (rho=0.610) had a moderate correlation with FC (P<0.001).

Conclusions Although existing Crohn’s disease endoscopic severity scores have moderate to strong agreement regarding endoscopic activity, they continue to have suboptimal correlation with laboratory non-invasive biomarkers.

Conflicts of interest

Authors do not have any conflict of interest to disclose.

Publication History

Article published online:
15 April 2024