Inclusion Criteria:  Adult inpatients from two centers, Zhongnan Hospital of Wuhan University and Thunder God Mountain Hospital, Wuhan, China. Experimental confirmed COVID-19 patients. Patients tested with autoimmunological detections including either ANA+ENA (Antinuclear antibody + Anti-extractable nuclear antigen antibody), Anti-cardiolipin antibody (ACA), Rheumatoid factor (RF), or Anti-streptolysin O antibody (ASO) detection.  Exclusion Criteria:  Minors. Experimental un-confirmed COVID-19 patients. Patients without autoimmunological detections.