Epithelial antigenic specificities of circulating autoantibodies in mucosal lichen planus

Mucosal lichen planus (LP) is an inflammatory disease of the mucous membranes of unknown origin. The antigen-specific autoantibodies or T cells responsible for this disease have not yet been established.

This study was designed to study the antigenic specificities of circulating antibodies in patients with mucosal LP and to review previous findings on this topic.

We tested a series of consecutive cases of mucosal LP in our clinic by enzyme-linked immunosorbent assay using desmoglein 3 (Dsg3) and BP180 fusion proteins.

Three of 22 patients were positive for anti-NC16A antibodies. Interestingly, we found a middle-aged woman with severe disease with circulating anti-Dsg3 antibodies at high levels, typical of pemphigus vulgaris. Levels of these antibodies positively correlated with the severity of clinical manifestations. We failed to detect anti-desmoglein antibodies in any other patient in our series and in the literature review.

Some patients with mucosal LP may present with circulating anti-BP180 antibodies at low levels. We also report the first case with positive anti-Dsg3 antibodies. The pathogenic relevance of these autoantibodies remains unknown.