A study of desmoglein 1 autoantibodies in pemphigus vulgaris: racial differences in frequency and the association with a more severe phenotype

Background Pemphigus vulgaris (PV) is characterized by pathogenic autoantibodies to desmoglein (Dsg) 3, but additional antibodies to Dsg1, the pemphigus foliaceus antigen, are detectable in some cases. Objectives To investigate the clinical significance of the presence of both Dsg 1 and 3 antibodies. Methods In 79 subjects with PV, enzyme-linked immunosorbent assays were used to detect IgG autoantibodies reactive with the ectodomain of Dsg1 and Dsg3. Results There was a clear association between the clinical phenotype and the Dsg antibody profile, All subjects had Dsg3 autoantibodies and 61% had coexisting Dsg1 antibodies (Dsg3+/Dsg1+). PV limited entirely to the mucosal surfaces was seen only in Dsg3+/Dsg1- patients, while additional Dsg1 antibodies (Dsg3+/Dsg1+) predicted cutaneous in addition to mucosal involvement. Although minor cutaneous involvement was observed in most Dsg3+/Dsg1- patients, severe cutaneous involvement was seen only in Dsg3+/Dsg1+ patients. Dsg1 antibodies were detectable early in the course of disease and their appearance did not relate to the use of systemic therapy, The proportion of Dsg1+ patients was higher in those of Indian origin compared with white northern Europeans (P < 0.05). Conclusions These data suggest that the presence of Dsg1 antibodies is predictive of a potentially more severe disease and that genetic factors may determine the Dsg antibody profile.