Presence of CD3-positive T-cells in oral premalignant leukoplakia indicates prevention of cancer transformation.

AIM Leukoplakias (LPLs) are lesions in the oral mucosa that have a potential to transform into oral squamous cell carcinoma (OSCC). As the degree of immunosurveillance may be important for this transformation to occur, the aim of this study was to determine the presence of immune cells in LPLs with dysplasia in relation to later development of OSCC. MATERIALS AND METHODS Biopsies from 16 patients with clinical diagnosis of LPL and histopathological diagnosis of hyperkeratosis with dysplasia were immunostained with antibodies to detect CD3(+) T cells, CD1a(+) LCs, Ki-67(+) and p53-expressing cells. Patients were divided into two groups: LPL with dysplasia that transformed into OSCC (LPL-dys) and that which did not (LPL-ca). RESULTS Quantitative analyses showed significantly lower numbers of CD3(+) T-cells in LPL-ca than in LPL-dys. No significant differences were detected when comparing LPL-dys and LPL-ca regarding CD1a(+), p53(+) and Ki-67(+) cells. CONCLUSION The number of CD3-expressing T-cells may be important for preventing malignant transformation of LPL.