Autoantibody profiles in microscopic colitis.

OBJECTIVE: The etiology of microscopic colitis is unclear; an autoimmune response and pharmacological induction have been proposed as possible mechanisms. We conducted a multicentre cross-sectional study to compare the antibody profiles of patients with collagenous and lymphocytic colitis with those of a control group.

METHODS: The medical histories and antibody profiles of 26 patients with collagenous and 16 patients with lymphocytic colitis were compared with the corresponding data of 43 controls without gastroenterological disease. Antibodies to the following structures were determined: intestinal goblet cells, antinuclear antibodies (ANA), antineutrophil cytoplasmic antibodies, anti-Saccharomyces cerevisiae antibody (ASCA), tissue transglutaminase, gliadin, pancreatic acini, glutamate decarboxylase, tyrosine phosphatase IA-2 and thyroid (microsomal anitbodies, MAB).

RESULTS: Patients with collagenous and lymphocytic colitis had been treated significantly more often with H(2)-receptor antagonists and non-steroidal anti-inflammatory drugs (P = 0.026 and 0.014, respectively). Additional diseases of presumed autoimmune etiology were present in 43% (18/42) of patients. Comparison with the controls showed significantly more positive findings for ANA immunoglobulin G (IgG), gliadin immunoglobulin A (IgA) and ASCA (IgA and IgG) in patients with collagenous colitis but not in those with lymphocytic colitis. Collagenous colitis was associated with positive ASCA in 15% of patients and lymphocytic colitis in 13%.

CONCLUSIONS: The autoantibodies investigated are of no diagnostic relevance to microscopic colitis. Positive ANA and strong associations with other autoimmune diseases point to an autoimmune etiology. H(2)-receptor antagonists and non-steroidal anti-inflammatory drugs might also be of pathogenetic significance.