[Role of staphylococcal infections in the occurrence of endemic Tunisian pemphigus].

Pemphigus is a severe autoimmune blistering disorder, in which immunoglobulin G autoantibodies are directed against desmosomal glycoproteins. The antibodies against desmogleine1 are prevalent in normal subjects living in Tunisia, that suggests the role of environment in the pathogenesis of this endemic type of pemphigus and the need for additional factors to switch from a subclinical form to a clinical form of the disease. The aim of this study was to investigate explanatory environmental factors. We tested the hypothesis that normal subjects whom presented staphylococcal infections have antibodies against desmoglein. We recruited 29 patients with staphylococcal infections from the dermatology department of the university hospital of Tunis. 29 controls healthy subjects are used to compare the prevalence of anti-desmoglein1 and 3 between these two groups. We used a specific and sensitive enzyme linked immunosorbent assay to detect autoantibodies against Dsg1. (10.3% versus 7% in healthy Tunisian blood donors: p < 0.05). Conversely, we observed a significant association with antibodies against Dsg3 (20.78% versus 3% in healthy Tunisian blood donors: p < 0.05). Subclasses analysis of anti-desmoglein antibodies showed that they were almost exclusively the IgG 1, 2 and 3 subclasses in positive normal sera. The antibodies against desmogleins binding activity of these positive sera were confirmed by indirect immunofluorescence analysis and by immunobloting using human epidermal extract. In conclusion, we detected autoantibodies in the sera of patients with staphylococcal infections and found elevated levels of autoantibodies against Dsg 3.