Predictive value of CD8highCD57+ lymphocyte subset in interferon therapy of patients with renal cell carcinoma.

Background: The aim of this retrospective study was to evaluate the significance of pre-treatment levels of peripheral blood lymphocyte subsets for survival of renal cell carcinoma (RCC) patients treated with interferon-a2b (IFN). Patients and Methods: CD3+, CD19+, CD16&56+, CD4+, CD8+, CD4+CD45ROhigh and CD8highCD57+ lymphocyte subsets in peripheral blood of 85 advanced RCC patients were determined using flow cytometry. The survival of IFN-treated and non-treated patients was analyzed by gradually testing different cut-off levels of each lymphocyte subset. Results: Advanced RCC patients with ≥ 30% CD8highCD57+ lymphocytes in the CD8+ subset had shorter survival compared to patients with < 30% CD8highCD57+ lymphocytes in the CD8+ subset (p = 0.01). Treatment with IFN increased overall survival only in the former subgroup of RCC patients (p = 0.02). Conclusion: The present study suggests that the percentage of CD8highCD57+ lymphocytes in the CD8+ subset may have a prognostic significance for advanced RCC patients and may have a predictive value in patient selection for survival benefit due to treatment with IFN.