Systemic cytokines in elderly patients with coronary heart disease at early recovery from COVID-19

Abstract

The development of COVID-19 is accompanied by involvement of various cytokines in pathological process. Their change depends on age, concomitant pathology and some other factors that have not been sufficiently studied in elderly patients with coronary heart disease (CHD). The content of cytokines in blood plasma of patients aged 60-74 in the early period of recovery from COVID-19 also remains unknown. The aim of our study was to determine the content of systemic cytokines in elderly patients with coronary heart disease at the early stages of recovery after COVID-19. The patients aged 60-74 with CHD who had COVID-19 of moderate severity grade (n = 40) made up the main group. in which the study of The cytokine levels were studied in blood plasma 3 to 4 weeks after recovery. The control group consisted of 38 elderly patients with coronary heart disease and negative tests for COVID-19. of cytokines in both groups were determined by means of flow cytometry with “Becton Dickinson FACS Canto 2 (USA)” machine using appropriate reagent sets. We have found that, in elderly patients with CHD at 3-4 weeks after recovery from COVID-19, if compared with elderly patients with CHD without COVID-19, the content of IL-6 in blood plasma was increased to higher degree and at statistically significant difference, up to 32.9±2.3 pg/mL versus 6.5±0.7 pg/mL in the control group (p < 0.001). Excessive content in the main group was also detected for IL-17 in blood plasma which was 25.4±1.9 pg/mL at the early post-COVID-19 period, whereas it was 7.8±0.7 pg/mL (p < 0.001) in the age-matched patients with CHD only. TNFα and IFNγ levels were elevated among 60-74-year-old patients with CHD and COVID-19 at 3-4 weeks after recovery, being 128.6±2.7 pg/mL and 57.6±2.8 pg/mL, respectively.  In control group, the concentration of these cytokines was significantly lower, i.e., 56.3±2.2 pg/mL and 25.9±1.7 pg/mL, respectively (p < 0.001). The changes in contents of other cytokines studied seemed less pronounced, and the level of IL-4 was not significantly different between the both groups. Hence, in elderly patients with CHD and COVID-19 at 3-4 weeks after recovery, IL-6, IL-17, TNFα and IFNγ are the most elevated cytokines at the systemic level.