Gut mucosal immunity to tissue transglutaminase in untreated celiac disease and other gastrointestinal disorders.

Tissue transglutaminase antibodies have not previously been measured in gut secretions. IgA anti-tissue transglutaminase and anti-endomysium antibodies were measured in paired serum and whole gut lavage fluid samples from patients with untreated celiac disease (N = 36), other gastrointestinal diseases (N = 235), and healthy volunteers (N = 13). HLA DQ2 typing was performed in the celiac patients. Whole gut lavage IgA anti-tissue transglutaminase antibody concentrations were raised in 83% of celiac patients, 4% of disease controls, and 8% of volunteers, and the antibody concentrations were significantly higher in celiac patients than in controls (P < 0.0001). Whole gut lavage IgA anti-endomysium antibodies were positive in 67% of celiac patients, but in none of the controls. Whole gut lavage, but not serum, IgA anti-tissue transglutaminase antibody concentrations were significantly higher in DQ2 positive than negative celiac patients. In conclusion, whole gut lavage IgA anti-tissue transglutaminase antibody concentrations are higher in untreated celiac disease than in other gastrointestinal diseases.