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

Abstract

The association of Durhing's disease, commonly referred to as dermatitis herpetiformis (DH), with gluten-sensitive enteropathy (GSE) is supported by the presence of villous atrophy and endomysial antibodies (EMA). EMA are found to be a marker of GSE both in celiac disease (CD) and in DH. Since tissue transglutaminase (tTG) is believed to be the major autoantigen in GSE, the aim of our study was to determine the specificity and sensitivity of anti-tTG antibody ELISA compared to the EMA indirect immunofluorescence test. We 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 patients with vesiculobullous disorders other than DH and 106 sera from normal healthy 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%) and in 36 of 58 CD (62%) patients. Both the EMA and the antibodies to tTG were present in the majority of patients with DH and CD when they were on a normal gluten-containing diet and were absent when on a gluten-free diet for an extended period of time. There were, however, small discrepancies in positivity 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 with EMA both in CD and in DH. The results of anti-tTG antibody and EMA assays were comparable; however, in DH, tTG was somewhat more sensitive than the EMA test. For screening of DH, it is advisable to perform both EMA and anti-tTG antibody tests.