Interleukin-6 inhibitors: from the therapy of immuno-inflammatory rheumatic diseases to use in COVID-19

The key role in the development of chronic autoimmune inflammation is played by pro-inflammatory cytokines, in particular, interleukin 6 (IL-6). The introduction into clinical practice of monoclonal antibodies inhibiting IL-6 is a significant event in rheumatology and is currently considered as a promising direction in the treatment of immuno-inflammatory rheumatic diseases. The first inhibitor of IL-6 (IL-6), which entered the practice of rheumatologists, was tocilizumab (TCZ), the second – sarilumab (SAR). Numerous studies have shown the high effectiveness of iIL-6: the use of drugs leads to a rapid decrease in the clinical manifestations of rheumatoid arthritis (RA) and a decrease in laboratory signs of inflammation, contributing to the achievement of low activity or remission, improves the quality of life of patients, and also slows down the X-ray progression of the disease. At the same time, iIL-6 has a satisfactory safety profile. The universal problem of our time – the pandemic of a new coronavirus infection – has led to attempts to use IL-6 in patients with severe and critical disease, since IL-6 plays an important role in the pathogenesis of COVID-19, which is confirmed by the results of numerous studies. However, data on the efficacy and safety of these drugs in COVID-19 are contradictory, which requires conducting larger-scale controlled studies. This review examines the issues of the effectiveness and safety of TCZ and SAR in rheumatological patients and in patients with COVID-19. The review is illustrated with examples from real clinical practice.