Coronavirus disease 19 (COVID-19) is a global health crisis on a planetary scale. COVID-19 in many people has mild or moderate manifestation, although significant number of people, especially the elderly, suffer heavy from this illness, which often resulting in death. There are reports of similarities in immune response between COVID-19 and some autoimmune diseases. Earlier, we have demonstrated that fraction of TCA-soluble blood serum proteins containing a 48 kDA fragment of unconvential Myosin C1 have linked with development of multiple sclerosis and rheumatoid arthritis. Here we analyze use of these proteins in determining the severity of disease in COVID-19 patients. We found that blood serum of COVID-19 patients in acute disease manifestation contains, in contrast to healthy individuals, the TCA-soluble proteins with molecular masses 48 kDa and 76 kDA which were identified as a short form of unconventional myosin 1c and a modified form of human serum albumin.