Lymphotyce T subsets and natural killer cells in Italian and Philippino blood donors

Background and Objectives The characterization of lymphocyte subsets in blood donors has been utilized to determine the normal ranges that can be related to race. A study was performed in blood donors from two racial groups - Caucasian (Italians) and Asian (Philippinos) - to define respective T-lymphocyte subsets and levels of cytokines. Materials and Methods Ninety-two blood donors (46 Italians and 46 Philippinos) were enrolled. Blood count and immunophenotyping of lymphocytes by flow cytometry were carried out, and cytokine production was tested in six blood donors of each group. Results Philippino blood donors showed a significantly higher mean value of leucocytes (P = 0.01) and lymphocytes (P < 0.001) than Italians. The mean absolute count of lymphocyte subsets CD3(-) CD16(+) CD56(+) and CD3(+) CD8(+) were both significantly higher in Philippino than in Italian subjects, respectively, P < 0.01 and P < 0.0001. Philippinos showed a statistically significant higher frequency of lymphocytes producing interferon-&gamma; (IFN-&gamma;) compared to Italians (P = 0.02). Conclusions T-lymphocyte subsets in Italian and Philippino blood donors seem to be correlated to ethnic background. The higher levels of CD3(+) CD8(+) T cells, natural killer (NK) cells and IFN-&gamma;-producing cells found in Philippinos suggest leucoreduction in Asian blood donors.