Immunodeficiency and autoimmunity patients with COVID-10 infection. Two faces of the same coin

ABSTRACT

Coronavirus disease 19 (COVID-19), is a complex and heterogeneous medical entity. It is caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). SARS-CoV-2 is an RNA virus similar to the SARS-CoV-1 and MERS-CoV viruses. COVID-19 disease is predominantly respiratory, but it can involve multiple systems. Although it may be asymptomatic or produce few symptoms in most infected patients, 20 % of those affected have severe or fatal disease with respiratory or/and multiple organ failure. The elimination of SARS-CoV-2 requires innate and adaptive immune responses, highlighting the importance of interferons, Toll-like receptors, serum complement, the response of T lymphocytes, and the formation of neutralizing antibodies against the virus. In a significant proportion of patients with severe COVID-19, the presence of primary immunodeficiencies (especially in the interferon pathway and T-lymphocyte signaling) has been described. Autoantibodies against various immunomodulatory proteins (cytokines, especially anti-interferons, chemokines, complement, and cell surface proteins), and antinuclear and antiphospholipid antibodies have also been reported. Autoimmune diseases can appear in the convalescent phase. Immunodeficiency and autoimmunity are responsible for viral escape and prolonged COVID. © 2022 Academia Nacional de Medicina. All rights reserved.