Serum immunoglobulins and complement (C'3) in oral lichen planus

Serum immunoglobulins and complement (C'3) were determined by single radial immunodiffusion according to the method of Mancini and co-workers in fifty patients with oral lichen planus and twenty persons with clinically normal oral mucosa. Significantly increased levels of serum IgG (p less than 0.05) and a significant reduction of serum IgA concentration (p less than 0.05) in the experimental group as compared with normal controls were observed. Mean serum IgM and complement (C'3) levels were similar in patients and controls. No correlation between disease variety or extensiveness and immunoglobulin or complement levels was noticed. These results suggest that patients with oral lichen planus may have a generalized immunologic disorder in which humoral immunity is disturbed. Whether humoral immunity is of etiologic significance, contributes to the disease process, or, finally, represents an event secondary to the pathologic changes seen in the disease remains to be determined.