The frequency of different T-cell receptor V-families in oral lichen planus and lichenoid contact lesions: an immunohistochemical study.

Oral lichen planus (OLP) and lichenoid contact lesions (CL) are recognized as different pathological conditions of the oral mucosa. Cutaneous delayed-type hypersensitivity to mercury displayed by patients with CL but not by OLP patients supports the concept of different etiological mechanisms behind the two lesions. It is not possible to reveal this difference by histopathological assessments, and differences in clinical appearances are at present the only way to discriminate between the two conditions. It has recently been observed that T cells in OLP lesions express T-cell receptors (TCR) belonging to the Vbeta3 family in a higher frequency than expected from a random distribution, suggesting an involvement of superantigens as an etiologic factor behind this condition. In an effort to discriminate more clearly between OLP and CL, and to provide clues to the etiological mechanisms behind the two lesions, the TCR V-family distributions in the inflammatory infiltrates of OLP and CL were compared. Biopsies were taken from 10 patients with manifest OLP and 10 patients with CL. Frozen sections were incubated with antibodies against TCR Vbeta3, Valpha2 and Vbeta5a utilizing a standard immunoperoxidase technique. The frequency of Vbeta3.1 (clone 8F10) was calculated as 7%, and for Valpha2 less than 3%, and the results did not reveal any differences between OLP and CL regarding the frequencies of T-cell V-families. Thus, it was not possible to discriminate between OLP and CL by immunohistochemistry staining for different V families.