ABSTRACT
The review considers various mechanisms for the development of autoimmune complications after COVID-19 disease. The significance of hyperactivation of the immune system with impaired tolerance is analyzed in detail, the issues of molecular mimicry and antigenic similarity of virus and human epitopes are considered. High expression of some autoimmune antigens and high levels of autoantibodies to a wide range of human antigens have been shown. The cytotoxicity and blocking effect of specific antiviral antibodies on various cells and tissues of the body and the importance of viral antigens as co-stimulatory molecules for the activation of T-and B-lymphocytes are discussed separately. The review hypothesizes “postcovidal humoral autoimmunity” based on an autoimmune response to various antigens and auto antigens that may cause autoimmune diseases of COVID-19 infection. © 2022, Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine. All rights reserved.