COVID-19 Induced Mixed Connective Tissue Disease (MCTD)—Case Report

Abstract

Mixed connective tissue disease (MCTD) is a rare systemic autoimmune disorder that damages multiple organs simultaneously and is associated with chronic inflammation, in which the signs of systemic sclerosis, systemic lupus erythematosus, and polymyositis can co-occur. Its distinctive feature and the basis for the diagnosis of MCTD is the presence of an antibody against the uridine-rich RNP of the cell nucleus (Anti-U1-RNP). It has been observed that intercurrent infections can trigger autoimmune diseases, however, the fact that viral infections-such as SARS-CoV-2-induce them is currently poorly understood. The present study raises the etiological role of the SARS-CoV-2 virus in the development of the disease. Authors describe the case of a 38-yearold patient in good general condition, who was diagnosed with mixed connective tissue disease three months after COVID-19 infection.