Phenotypic identification of mononuclear cells in oral premalignant lesions and cancer by monoclonal antibodies.

Abstract

To explore the nature and importance of mononuclear cells of different phenotypes in oral premalignant lesions and oral cancer, we studied biopsy specimens from 21 oral red and/or white lesions (6 hyperkeratosis, 3 mild dysplasia, 4 severe dysplasia and 8 squamous cell carcinoma), using monoclonal antibodies and avidin-biotin-peroxidase complex staining. Peripheral blood samples (PB) from 4 normal subjects and 5 reactive lymph nodes (LN) were used as controls for the technique. T11-positive cells were the predominant phenotype (74-78%) in all cases examined. The T4/T8 ratio in severe dysplasia was significantly lower than that in mild dysplasia (p less than or equal to 0.05). These observations support the hypothesis of a role for cellular immune responses in oral premalignant lesions and oral cancer. The predominance of T cells may represent the local expression of immunity against antigens (viral or other). The decreased T4/T8 ratio observed in severe dysplasia may represent a transitory stage of local immunosuppression, which may be of critical importance for the progression into carcinoma. Phenotypic variations in mononuclear cell infiltrates in these conditions could be diagnostic value.