2.1 Patients and controls
Among all participants, pregnant women and patients with various cancers and known defects of the immune system (such as HIV infection, haematologic diseases or transplantation history) were excluded.
SLE group:Ninety-seven patients diagnosed with SLE (8 males and 89 females, median age of 34 years) were selected from Zhongshan Hospital, the Medical College of Xiamen University, from April 2019 to June 2020. In this study, we subdivided the patients in the SLE group into two groups based on the presence or absence of anti-dsDNA antibodies (anti-dsDNA+ and anti-dsDNA- groups) before treatment. All SLE patients and LN diagnosis  and the disease activity of SLE patients evaluation were described as previously reports[11,12],[13].
  Non-SLE group: This group was composed of two subgroups, the rheumatoid arthritis (RA) group and the other autoimmune diseases (OAD) group. Twenty-six patients (7 males and 19 females, median age of 31.5 years) were diagnosed with RA according to the 2010 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) rheumatoid arthritis (RA) classification criteria (2010 RA criteria)[14]. Twenty-three patients (5 males and 18 females, median age of 36 years) were recruited with other autoimmune diseases. Of these patients, 13 were diagnosed with Sjögren’s syndrome (SS), 6 were diagnosed with mixed connective tissue disease (MCTD), 3 were diagnosed with dermatomyositis, and 1 was diagnosed with anti-phospholipid syndrome (APS).
Healthy control group: 50 cases from 10 healthy males and 40 healthy females, with an median age of 31 years, without any risk factors or chronic diseases.