ISOLATION OF ANTIGENS RECOGNIZED BY CELIAC-DISEASE AUTOANTIBODIES ANDTHEIR USE IN ENZYME-IMMUNOASSAY OF ENDOMYSIUM AND RETICULIN ANTIBODY-POSITIVE HUMAN SERA

Components were isolated from rat liver, sheep lung, rhesus and orang- utan intestine. In enzyme immunoassay, these components detected 57%, 72%, 84% and 88% of human sera containing endomysium and reticulin ant ibodies (EmA and ARA). At most, 7% of EmA/ARA-negative sera reacted wi th the antigens. The spectrum of EmA/ARA-positive sera reactive with t he various components was different but overlapping. When the antigens of sheep lung and orang-utan intestine were used as a cocktail, 98% o f EmA/ARA-positive sera (45/46), but only 2% of control sera (1/46) we re detected. The isolated antigens from sheep lung and monkey intestin es were able to absorb EmA and ARA from human sera and thus should be suspected to contain the epitopes recognized by EmA and ARA, whereas t he rat liver component did not bind. Therefore, the spectrum of autoan tibodies in coeliac disease might comprise more than that covered by t he terms EmA and ARA. The N-terminal amino acid sequence of some of th e antigens was homologous with casein, gliadin, fibrinogen, and collag en.