Possible role of Mycobacteria in inflammatory bowel disease

Abstract
An unclassifiedMycobacterium species has been isolated from two patients with Crohn's disease (CD). Antibodies to the unclassified mycobacteria cross-reacted withMycobacterium paratuberculosis. Because of this cross-reactivity, an enzyme-linked immunosorbent assay (ELISA) was used to examine the sera of inflammatory bowel disease (IBD) patients, both CD (N=56), and ulcerative colitis (UC) (N=34), for antibodies toM. paratuberculosis, Mycobacterium kansasii, andMycobacterium tuberculosis. Controls consisted of healthy, PPD-negative individuals (N=67), and from PPD-positive patients (N=41). Eighteen resected CD patients were also examined. CD patients had a statistically significant increase in antibody titer (P=0.0003) toM. paratuberculosis compared to healthy controls. Although patients with positive PPD had elevated titers to this organism, the positive response of CD patients was not related to PPD responsiveness, area of involvement in the gut, nor to activity of the disease process.