The epidermolysis bullosa acquisita antigen (type VII collagen) is present in human colon and patients with Crohn's disease have autoantibodies to type VII collagen

Epidermolysis bullosa acquisita is an autoimmune blistering disease of the skin characterized by IgG autoantibodies against type VII collagen. Systemic diseases are often associated with epidermolysis bullosa acquisita, Crohn's disease being the most frequent. This study sought to determine if type VII collagen, the epidermolysis bullosa acquisita autoantigen, was present in normal human colon by western blotting and immunofluorescence. The 290 kDa type VII collagen alpha chain was demonstrated by western blotting in four normal intraoperative colon specimens. Antibodies to type VII collagen labeled the junction between the intestinal epithelium and the lamina propria. We also used an enzyme-linked immunosorbent assay to test sera from patients with Crohn's disease (n = 19), ulcerative colitis (n = 31), celiac disease (n = 17), rheumatoid arthritis (n = 15), and normal controls (n = 16). It was found that 13 of 19 patients with Crohn's disease and four of 31 patients with ulcerative colitis demonstrated reactivity to type VII collagen. Sera from control subjects, patients with celiac disease or rheumatoid arthritis were negative. The sera from Crohn's disease patients also reacted with type VII collagen by immunoblot analysis. It was concluded that patients with inflammatory bowel disease may have IgG autoantibodies to type VII collagen, which exists in both the skin and the gut.