Anti-Saccharomyces cerevisiae Antibodies as a Prognostic Biomarker in Children With Crohn Disease

Objective: Although anti-Saccharomyces cerevisiae antibodies (ASCAs) could be a useful biomarker in differentiating Crohn disease (CD) from ulcerative colitis (UC), their role as prognostic markers in children with CD has been underinvestigated. This longitudinal prospective observational study aimed to assess the prognostic value of ASCA status among children with CD managed using biologics. Methods: The study population comprised children with inflammatory bowel disease diagnosed with CD from 2012 to 2018. Cox regression model with adjustment for a priori covariates was used to examine the response to anti-tumor necrosis factor (TNF) biological therapy among ASCA-positive patients in comparison to ASCA-negative patients. Results: There were 273 measurements available from the study cohort comprising children with CD, who were followed up for a median duration of 14 months (interquartile range 5-42). ASCA-positive patients had a higher risk for moderate to severe clinical disease (odds ratio 2.88; 95% confidence interval [CI] 1.2-7.55) and extensive endoscopic distribution (odds ratio 3.30; CI 1.12-9.74) at baseline in comparison to ASCA-negative patients, respectively. In comparison to ASCA immunoglobulin G (IgG)-negative patients, ASCA IgG-positive patients who were treated with biologics had a significantly lower relapse rate (adjusted hazard ratio 0.12; CI 0.02-0.93). Ten (14%) patients had an unstable ASCA value with either ASCA immunoglobulin A or ASCA IgG status changing from positive to negative or vice versa. Conclusions: ASCA-positive children with CD present with more extensive (endoscopic) and clinically severe disease. ASCA IgG is a useful prognostic marker among children with CD who receive biologics.