Anti-Saccharomyces cerevisiae antibodies (ASCA), phenotypes of IBD, and intestinal permeability: A study in IBD families

Background: Serologic markers anti-Saccharomyces cerevisiae antibodies (ASC A) and antineutrophil cytoplasmic antibodies with perinuclear staining (pAN CA) have been proposed to study the immunopathogenesis of IBD. Their measur ement may allow better phenotyping of the disease and the detection of subc linical disease. Aims: To test the hypothesis that serological markers iden tify an immunologic trait related to disease susceptibility. We also wanted to test the hypothesis that ASCA is a marker related to abnormal tissue pe rmeation by common antigens. Methods: We studied the prevalence of pANCA an d ASCA in a large cohort of sporadic and familial inflammatory bowel diseas es and their unaffected relatives and spouses. Kinetics of ASCA was studied and the relationship between ASCA and Cr-51-EDTA intestinal permeation was investigated. Results: ASCA was associated with sporadic Crohn's disease ( CD) (63%), with Crohn's patients belonging to pure CD families (62%) and al so with their unaffected family members (21%). pANCA was associated with UC (58%). The prevalence of ASCA in CD patients belonging to mixed families w as strikingly low (33%), ASCA was a stable marker throughout the disease an d was not related to an increased small intestinal permeability. Conclusion : ASCA is strongly associated with familial CD in Belgium, and 21% of healt hy family members also display the marker. The association is much weaker i n patients belonging to mixed families. ASCA is a stable marker and is not a secondary phenomenon due to increased intestinal permeability.