OXIDATIVE MODIFICATION OF PROTEINS IN THE SYNOVIAL FLUID OF PATIENTS WITH OSTEOARTHRITIS AFTER SARS-CoV 2-INFECTION

Abstract

The pandemic of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has made a serious public health threat worldwide. It has caused many complications and deaths, so millions of people are at risk in more and more countries. A special group consists of patients with chronic diseases, particularly osteoarthritis. It is known that the development of osteoarthritis is associated with oxidative stress and excessive production of free radicals. Proteins are highly sensitive to free radical oxidation, so their oxidation level reflects the oxidant-antioxidant balance in the body. The aim of the work was to determine the concentration of products of oxidative modification of proteins and sulfhydryl groups in the synovial fluid 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. In the conducted studies, the products of protein oxidation in the synovial fluid of patients of all experimental groups were evaluated. The concentration of products of oxidative modification of proteins was determined by the level of carbonyl derivatives, which are detected in the reaction with 2,4-dinitrophenylhydrazine. The concentration of total, protein-bound and non-protein sulfhydryl (SH) groups was measured by the Ellman method. Processing of research results was carried out using generally accepted methods of variational statistics. It was established that in the synovial fluid of patients with osteoarthritis of the knee joints who contracted COVID-19, the concentration of products of oxidative modification of proteins increased. Under the same experimental conditions, the concentration of sulfhydryl groups decreased. The detected changes indicate a violation of the oxidant-antioxidant balance in the synovial fluid of patients with osteoarthritis after SARS-CoV-2 infection. This indicates the prevalence of free radical processes and the development of oxidative stress directly in the joint. Our results indicate that patients with osteoarthritis may develop more severe joint damage after infection with COVID-19.