APOPTOTIC INTERACTIONS IN LONG COVID AND AGING

Aging is a natural process that engages all the body’s systems and tissues. Aging leads to chronic inflammation, contributing to the overall aging process. A persistently activated immune system becomes pro-inflammatory, contributing to age-related inflammation. Objective - to assess the level of receptor-ligand interactions of apoptotic markers on cytotoxic CD8 and NK (CD56) cells in patients with long COVID. Research methods comprised clinical evaluation of patients, flow cytometry, and statistical data analysis. Results. There was a significant reduction in CD3, CD4 lymphocytes, and NK cells among long-COVID patients, while CD8 and CD19 cells were significantly elevated compared to the control group of middle-aged individuals. Concerning the expression of the FasL ligand in long-COVID patients, a notable difference was found between long-COVID patients and older age groups. In contrast, no significant difference was noted in the expression of FasR on NK cells. In terms of expression of the PD1R receptor and its ligand PD1L on cytotoxic CD8 cells, a notable difference was observed between the long-COVID patient group and the middle-aged control group; however, no significant difference was noted between the long-COVID patient group and the older control group. Conclusions. Changes in the expression of apoptotic markers in long COVID-19 patients and elderly individuals correlate, suggesting a connection between aging and infectious burdens in patients.