Relative Sensitivity and Specificity of Serodiagnostic Tests for Gluten-Sensitive Enteropathy

The occurrence of AGA and ARA has been compared in a few small groups of patients. With both IIF and ELISA tests Unsworth et al.⁵ and Volta et al.⁷ found a higher prevalence of AGA than of ARA in their dermatitis herpetiformis patients on a normal diet (Table 1). In contrast, Ljunghall et al.³ reported more ARA than AGA, i.e., anti-wheat grain antibodies, in their dermatitis herpetiformis patients. We examined ten children with dermatitis herpetiformis and found IgA-ARA in 90% and IgA-AGA in 30% of these patients.⁶ Later on we also compared the occurrence of AGA to that of EmA in 29 adult dermatitis herpetiformis patients on a normal diet. The frequency of IgA-class AGA was 59% and that of EmA 76%.⁴ These results, although based on a small group of dermatitis herpetiformis patients, suggest that ARA and EmA may be a better detector of dermatitis herpetiformis patients with mild jejunal damage. However, if we compare the antibody frequencies in patients with severe villous atrophy (SVA), the prevalences are not very different.^1,2 Of our dermatitis herpetiformis patients with SVA, 12 (86%) had IgA-AGA, 13 (92%) had IgA-ARA, and 14 (100%) had IgA-EmA (Table 1). Further studies on a large group of patients are needed to confirm which of these tests has the best sensitivity and specificity in detecting dermatitis herpetiformis patients with small intestinal damage.138