DNA damage in human skin fibroblasts from patients with dermatitis herpetiformis

Dermatitis herpetiformis (DH) and celiac disease (CD) are considered to be autoimmune diseases that share a specific trigger (gluten) and a common genetic background (HLA-DQ2/DQ8). However, the pathogenesis of DH is not yet fully understood and no data are available regarding a possible role of fibroblasts in this disease. The aim of this study was to assess baseline DNA damage in fibroblasts in DH-diagnosed patients vs. fibroblasts of controls without DH or CD. Primary fibroblast cultures were derived from dermal biopsies from DH patients and controls (without DH or CD). In vitro genotoxic damage was investigated using the comet assay and ɣH2AX test after different treatments (with 33mer peptide and digested gliadin [DG]) in order to investigate a correlation between oxidative stress (evaluated by reactive oxygen species formation) and glutathione content. Our results demonstrate a difference in baseline DNA damage between cutaneous fibroblasts of controls and DH patients, moreover, DNA damage significantly increased after exposure to gluten (DG and 33mer peptide) in fibroblasts from DH patients. DNA damage in fibroblasts from patients under dapsone treatment was similar to that of the control group. Our data indicate that oxidative stress and DNA damage may be characteristics of fibroblasts from DH patients who are not treated with dapsone, particularly after exposure to gliadin peptides.