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 recogn ized as different pathological conditions of the oral mucosa. Cutaneou s delayed-type hypersensitivity to mercury displayed by patients with CL but not by OLP patients supports the concept of different etiologic al mechanisms behind the two lesions. It is not possible to reveal thi s difference by histopathological assessments, and differences in clin ical appearances are at present the only way to discriminate between t he two conditions. It has recently been observed that T cells in OLP l esions express T-cell receptors (TCR) belonging to the V beta 3 family in a higher frequency than expected from a random distribution, sugge sting an involvement of superantigens as an etiologic factor behind th is condition. In an effort to discriminate more clearly between OLP an d CL, and to provide clues to the etiological mechanisms behind the tw o lesions, the TCR V-family distributions in the inflammatory infiltra tes of OLP and CL were compared. Biopsies were taken from 10 patients with manifest OLP and 10 patients with CL. Frozen sections were incuba ted with antibodies against TCR V beta 3, V alpha 2 and V beta 5a util izing a standard immunoperoxidase technique. The frequency of V3.1 (cl one 8F10) was calculated as 7%, and for V alpha 2 less than 3%, and th e results did not reveal any differences between OLP and CL regarding the frequencies of T-cell V-families. Thus, it was not possible to dis criminate between OLP and CL by immunohistochemistry staining for diff erent V families.