Background. The emergence of a new severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) has created a serious global threat to the health of people in various countries. The 2019 coronavirus disease (Coronavirus disease 2019, COVID-19) has caused the development of many complications in the population of most countries of the world. Currently, many people have felt the unpleasant consequences of the coronavirus infection. Among them, a special group consists of patients with chronic diseases, particularly osteoarthritis. The development of inflammation and intensification of free radical processes is a leading link in the pathogenesis of osteoarthritis. Inflammatory and degenerative processes that develop in osteoarthritis cause modification of the molecular and cellular composition of the synovial fluid. Methods. The aim of the work was to determine the expression of (Prostaglandin-endoperoxide synthase 2) and NOS2 (Nitric Oxide Synthase 2) genes in synovial fluid cells of patients with osteoarthritis after SARS-CoV2 infection. All study participants were divided into two groups. The first group (n = 22) is patients with osteoarthritis of the knee joints II-III degree. The second group (n = 14) is patients with osteoarthritis of the knee joints II–III degree, who suffered a mild and moderate form of COVID-19 6–9 months ago. Expression of PTGS2 and NOS2 genes was determined in nuclear cells of synovial fluid. RNA was obtained by the Chomczynski method. Synthesis of cDNA and quantitative polymerase chain reaction in real time (Real-time PCR, qPCR) using the commercial kit "Thermo Scientific Verso SYBR Green 1-Step qRT-PCR ROX Mix" ("Thermo Scientific, Lithuania). Processing of research results was carried out using generally accepted methods of variational statistics. Results. In patients with osteoarthritis of the knee joints after SARS-CoV2 infection, the expression of PTGS2 and NOS2 genes increases in nuclear cells of the synovial fluid compared to patients diagnosed with osteoarthritis. Conclusions. Our results indicate that patients with osteoarthritis may develop a more severe course of synovial inflammation after infection with COVID-19.
