Correlation between IgA antiendomysial antibodies and subtotal villous atrophy in dermatitis herpetiformis.

Serum IgA antiendomysial antibodies (EmA) were present in 20 (64.5%) of 31 patients with dermatitis herpetiformis (DH) on a normal diet. A significant correlation was found between these antibodies and the severity of gluten-induced jejunum damage. IgA EmA were positive in 19 (86%) of the 22 DH patients with subtotal villous atrophy, in comparison with the positivity of only one (11%) of the nine DH patients with less severe intestinal involvement (partial villous atrophy or mild abnormalities). The specificity of this test for gluten-sensitive enteropathy was 100%, these antibodies being consistently negative in biopsied disease controls showing a normal jejunal mucosa. Moreover, IgA EmA proved to be useful in monitoring the response to gluten withdrawal in DH patients, as these antibodies always disappeared in all the DH cases studied after 1 year of gluten-free diet together with the regrowth of jejunal villi. The strict relationship between IgA EmA and subtotal villous atrophy is more helpful still since the enteropathy present in DH is usually symptomless and therefore difficult to suspect.