DETECTION AND CHARACTERIZATION OF ANTI-ENDOMYSIAL ANTIBODY IN CELIAC-DISEASE USING HUMAN UMBILICAL-CORD

Objectives: To verify the effectiveness of human umbilical cord (HUG) in the detection of anti-endomysial antibodies (AEA) in coeliac diseas e and to characterize further these antibodies by studying tissue adso rption characteristics and antibody inhibition studies. Methods: AEA w ere detected on HUC and primate oesophagus in a blind study, using ser a from 46 patients with untreated coeliac disease and 108 controls. Ti ssue adsorption studies were performed using homogenized tissue from r odent liver, HUG, primate oesophagus and human liver. Sera were adsorb ed with each of these homogenates and antibody was detected using HUG, primate oesophagus and rat kidney. In the inhibition experiments AEA was detected on HUG, and inhibition of binding was attempted by preinc ubating the sections with antibodies against collagen types I, III and IV. Results: The sensitivity of AEA was 91% when detected on HUG, 89% when detected on primate oesophagus (93% and 91%, respectively, after exclusion of 1 patient with IgA deficiency). Specificity was 100% for both assays. Tissue adsorption studies showed identical results for A EA detected on both HUC or primate oesophagus, whereas antireticulin a ntibody was adsorbed only by rodent tissue. Blocking of the HUC with a nticollagen antibodies did not prevent binding of AEA. Conclusions: HU C is an effective substrate for the detection of AEA and may be superi or to primate oesophagus. The antibody detected by HUC shows identical tissue adsorption specificities to that detected on primate oesophagu s.