Deposits of immunoglobulin G and complement C3 in recurrent aphthous ulcerations.

Deposits of immunoglobulin G (IgG) were demonstrated at the basement membrane zone in lesions from 14 out of 16 patients with recurrent aphthous ulcerations (RAU) by means of an immunofluorescent (IF) staining technique. Deposits of complement C3 were demonstrated at the same localization in lesions from 16 out of 16 patients with RAU. Similar deposits of C3 were demonstrated in 11 out of 12 experimentally produced oral wounds (EOW). Immunoglobulin deposits were not detected in the EOW. No deposits of immunoglobulin or C3 were revealed in 12 biopsies from normal oral mucosa (NOM). Further, the IF investigation demonstrated circulating autoantibodies against the cytoplasm of autologous oral epithelial cells in patients with RAU. The specificity of the present immunologic reactions and their possible role in the pathogenesis of RAU are discussed.