Celiac disease serology in dermatitis herpetiformis. Which is the best option for detecting gluten sensitivity?

Dermatitis herpetiformis (DH), a well-established gluten-sensitive skin disorder presenting variable degrees of enteropathy, constitutes a very useful model in order to assess the utility of the celiac disease (CD)-related serology in patients with mild intestinal damage. Our aim was to explore comparatively the performance of a panel of CD-related serologic tests in patients with DH. We assessed a series of 18 consecutive patients with skin biopsy proven DH presenting the overall spectrum of intestinal damage ranging from normal mucosa (n = 6) to total villous atrophy (TVA) (n = 6) through partial villous atrophy (PVA) (n = 6). Sera were obtained from all patients while consuming a gluten containing diet. Serologic tests were antiendomysial, anti-tissue transglutaminase and antigliadin antibodies, and newly developed tests detecting both antibody isotypes (IgA and IgG) against deamidated synthetic gliadin-derived peptides (a-GDP). Serologic tests had a variable behaviour depending on the degree of enteropathy. While the majority of tests detected patients with TVA, only 50% of those with normal histology had positive assays. Patients with PVA had discordant results. Classical CD-specific tests were positive in only some patients with mild damage while all of them were identifed by a single assay detecting both isotypes of a-GDR CONCLUSION: The detection of a-GDP antibodies was the most reliable tool in order to identify gluten sensitivity in DH patients presenting a wide range of intestinal damage. Further studies should explore if these findings can be extrapolated to patients with CD having mild enteropathy.