Analysis of peripheral blood lymphocyte subsets in normal Saudi males by flow cytometry

Lymphocyte immunophenotyping using flow cytometer has become an important tool for clinical patient management as well as for research and epidemiological studies. We examined the distribution of CD3 (all T cells), CD4 (T helper/inducer cells), CD8 (T suppressor/totoxic cells), CD16 (natural killer cells) and CD19 (B cells) in 150 healthy Saudi male blood donors using flows cytometry. The two-color labeled cells were analyzed by using the flow cytometer (FACScan, Becton-Dickinson, San Jose, California, USA) and the dual fluorescent subsets were discriminated by Simultest software. The distribution of T lymphocytes, B lymphocytes, and natural killer (NK) cells were similar to those reported in other populations as well as in normal Caucasian expatriate donors (all males) (n = 40) who were included in this study as controls. However, a significantly decreased CD4/CD8 ratio was observed in most Saudi blood donors. These lower ratios were due to decreased CD4 together with an increase in CD8 cells. Significant (P<0.00001) difference in CD4/CD8 ratio in our study may be due to environmental factors such as ultraviolet radiation and stress (heat) as well as some genetic factors.