Evaluation of the peripheral T cell subsets and NK cells within age in the Erbil city population

Immunosenescence, or immunological aging, is a condition in which the immune system's ability to operate declines with age. One important indicator of a diseased or healthy state is the shift in immunological phenotype. This study was conducted to investigate the impact of aging on human peripheral lymphocytes. The population of the old age group consisted of 61- to 92 year-old individuals of both genders and without chronic diseases. Peripheral blood samples were collected from 75 cases of old age in the EDTA tube, the examination of immunophenotype was carried out using flow cytometry. There was a significant decrease in CD3+ T cells, CD8+ T cells, and naïve T cell populations (naïve CD4+, naïve CD8+) in the old age group. However, there was not a significant change in the CD4+ cells, followed by a significant increase in the ratio of CD4:CD8 T cells. On the other hand, memory T cells (memory CD4+, memory CD8+) and NK cells increased significantly with age group. In conclusion, this study depicts the dynamic change of T lymphocyte subsets and NK cells by aging; these alterations revealed impairment of cellular immunity in the elderly population and increased susceptibility of the aged body to developing diseases.