T cells with the CD8+CD28– phenotype are CD8+ lymphocytes with regulatory function. Their increased numbers were observed in infections, autoimmune and neoplastic diseases, and in elderly healthy individuals. CD8+CD28– lymphocyte levels in patients with cutaneous T-cell lymphoma (CTCL) has not yet been described. The aim of the study was to determine their levels in these patients’ peripheral blood and cutaneous infiltrates and their relation to the clinical stage of disease.

Forty-one untreated patients, 26 males and 15 females, with CTCL were enrolled in the study. CD8+CD28– lymphocyte levels were determined by flow cytometry in peripheral blood and by immunochemistry in skin infiltrates.

The percentage of CD8+CD28– lymphocytes in the peripheral blood of the patients was significantly higher than in the controls. Patients with advanced disease displayed a higher percentage of CD8+CD28– lymphocytes in the peripheral blood and skin than did the individuals with early stages of the disease. Moreover, positive correlations between CD8+CD28– lymphocyte level in peripheral blood and age, clinical stage, and the levels in the skin infiltrates was revealed. Additionally, the percentage of CD8+CD28– T cells in the skin infiltrates correlated positively with age and clinical stage of the disease.

These data suggest that CD8+CD28– lymphocytes play an important role in the development of immunotolerance in the progression of cutaneous T-cell lymphoma.