EFFECT OF INTESTINAL RESECTION ON SERUM ANTIBODIES TO THE MYCOBACTERIAL 45 48 KILODALTON DOUBLET ANTIGEN IN CROHNS-DISEASE/

Interest in the role of mycobacterial infection in Crohn's disease has been revived by the cultural detection of Mycobacterium paratuberculo sis in patients with Crohn's disease. This hypothesis was examined ser ologically using assays with high specificity for Crohn's disease. The effect of intestinal resection on serum antibodies specific for Crohn 's disease was investigated with an immunoblot assay and an enzyme Lin ked immunosorbent assay using the 45/48 kilodalton doublet antigen of Mycobacterium tuberculosis. Antibodies were detected in 64.7% of patie nts with Crohn's disease (n=17), 10% of patients with ulcerative colit is (n=10), 5% of patients with carcinoma of the colon (n=20), and none of 10 healthy subjects with the immunoblot assay. Statistical compari son of the Crohn's disease patients with each control group resulted i n p=0.0000236. Immunoglobulin G was essentially unchanged 75 days (mea n) after surgery. After more than 180 days, however, the antibody resp onse was reduced in all of five patients studied, and was no longer de monstrable in two of them (40%). Simultaneously, the Crohn's disease a ctivity index (CDAI) decreased. Both the high specificity of this assa y for Crohn's disease and the diminished antibody response after intes tinal resection in parallel with decreased CDAI support a mycobacteria l aetiology of Crohn's disease.