Unmasking anti-endomysial antibodies in coeliac subjects positive for anti-smooth muscle antibodies


M Lapini, Department of Paediatrics, University of Florence, Meyer Hospital, Via L. Giordano 13, Florence, Italy (Tel. +39 55 5662482, fax. +39 55 570380)


Anti-endomysial antibodies assayed by indirect immunofluorescence presently represent the most advanced in vitro method for diagnosing coeliac disease. While testing the serum of patients affected by coeliac disease for anti-endomysial antibodies, we noticed in some samples the presence of anti-smooth muscle antibodies. This led us to the hypothesis that anti-smooth muscle antibodies might mask the presence of anti-endomysial antibodies. The aim of our research was to develop a method that could confirm our hypothesis. Here we show that the AEA response can be effectively unmasked by increasingly diluting anti-smooth muscle antibodies-positive serum.