Is there a role for tumor necrosis factor-alpha (TNF-α) in oral lichen planus?

Oral lichen planus (OLP) is a T cell-mediated inflammatory disease of the oral mucosa. T lymphocytes accumulate within OLP lesions by extravasation from the local microvasculature and subsequent migration to the oral epithelium. Tumor necrosis factor-alpha (TNF-α) is a cytokine involved primarily in T cell-mediated immunopathological reactions, and it is implicated in diseases which bear clinical and histological similarities to OLP. This review examines the role of TNF-α in the initiation and progression of OLP, and summarises evidence for a key role for TNF-α in this disease. A unifying hypothesis for the involvement of TNF-α in the immunopathogenesis of OLP is presented. Based on this model, a variety of current therapies are explained and several alternative approaches suggested.