Novel HLA class II-associated structural patterns in coeliac disease and type I diabetes.

Cell membrane antigens were precipitated from EBV transformed cell lines by a monomorphic DR monoclonal antibody. Three mutually exclusive patterns with two glycoproteins (g25 and g28) that had not been previously identified, were observed. The first, g25+/g28- was found in all cell lines from 40 healthy individuals; a second, g25-/g28- was found in 4/7 coeliac and 2/4 IDDM patients and a third, g25+/g28+ was found in 3/7 coeliac and 1/4 IDDM patients. RFLP analysis with Class II alpha and beta chain probes and several restriction enzymes did not correlate with either of the disease associated patterns. Several possibilities regarding the identity and mode of action of the two polypeptides are described.