Tissue transglutaminase and endomysial antibodies - Diagnostic markers of gluten-sensitive enteropathy in dermatitis herpetiformis

The association of Durhing's disease, commonly referred to as dermatitis he rpetiformis (DH), with gluten-sensitive enteropathy (GSE) is supported by t he presence of villous atrophy and endomysial antibodies (EMA), EMA are fou nd to be a marker of GSE both in celiac disease (CD) and in DH. Since tissu e transglutaminase (tTG) is believed to be the major autoantigen in GSE, th e aim of our study was to determine the specificity and sensitivity of anti -tTG antibody ELISA compared to the EMA indirect immunofluorescence test. W e studied 44 cases of DH, confirmed by the presence of IgA immune deposits in the dermal papillae, and 58 cases of CD conforming to the International Criteria of Diagnosing CD, The control group comprised 161 sera from patien ts with vesiculobullous disorders other than DH and 106 sera from normal he althy blood donors, Anti-tTG antibodies were detected in 36 of 44 DH (79%) and in 32 of 58 CD (55%) patients. EMA were positive in 33 of 44 DH (74%) a nd in 36 of 58 CD (62%) patients. Both the EMA and the antibodies to tTG we re present in the majority of patients with DH and CD when they were on a n ormal gluten-containing diet and were absent when on a gluten-free diet for an extended period of time. There were, however, small discrepancies in po sitivity and negativity in tTG antibody-positive and EMA-negative patients and vice versa. There seems to be a correlation between the EMA titers and the anti-tTG antibody levels. This study confirms the high specificity and sensitivity of anti-tTG antibody ELISA for GSE and its strong correlation w ith EMA both in CD and in DH. The results of anti-tTG antibody and EMA assa ys were comparable; however, in DH, tTG was somewhat more sensitive than th e EMA test. For screening of DH, it is advisable to perform both EMA and an ti-tTG antibody tests. (C) 2001 Academic Press.