Lichen planus-specific antigen in oral lichen planus and oral lichenoid drug eruptions

Objective. To investigate the usefulness of richen planus-specific antigen as a marker to distinguish idiopathic oral richen planus from oral lichenoi d drug eruptions. Study design. Biopsy samples were taken from 6 patients with oral lichenoid drug eruptions and 6 patients with idiopathic oral lichen planus. Each bio psy sample was examined for the presence of lichen planus-specific antigen by using a modification of a previously described immunofluorescence method that uses autologous serum and also allogenic sera from the remaining 11 c ases. Results, All autologous and allogenic immunofluorescence tests showed negat ive findings for lichen planus-specific antigen. Conclusions. Lichen planus-specific antigen is not a useful marker to disti nguish oral lichenoid drug eruptions from idiopathic richen planus. This fi nding is in contrast with our findings in an earlier study of basal cell cy toplasmic autoantibodies.