[Biomarkers and Their Role in Understanding Osteoarthritis]

Osteoarthritis (OA) is a degenerative joint disease characterized by progressive damage and loss of articular cartilage with concomitant structural and functional changes in the joint. It is the most common cause of joint pain globally and the resulting productivity loss to the economy. The clinical symptoms of osteoarthritis are mostly determined by the difficulties of patients related to the development of articular degenerative changes, which secondarily lead to joint stiffness and functional limitation. The diagnosis of this disease is currently based on typical clinical symptoms and radiographic findings (e.g. joint space narrowing, osteophytes, subchondral sclerosis, etc.). These parameters, however, are difficult to detect in the early stages of the disease and are most often recognized in the advanced stages. For these reasons, the diagnosis of osteoarthritis is often delayed until irreversible destruction of joint tissue occurs and conservative treatment is less effective. Despite recent scientific progress in understanding the genetic and molecular principles of joint degeneration, currently there is no reliable causal therapy for OA. This review aims to summarize current knowledge of osteoarthritis and possible future directions for diagnosis and early intervention. One of such directions is the study of the so-called biomarkers. A biomarker is defined as an indicator of biological processes and can include radiographic, histological, physiological, or molecular characteristics. In particular, molecular biomarkers are widely studied in knee OA. Attention of the research community is focused on the study of biomarkers as a method of detection and prediction of the early stages of osteoarthritis before irreversible joint damage occurs. Biomarkers help develop more effective and, above all, personalized treatment, thus improve the overall clinical approach to the patient.