Antibody responses following the surge of SARS-CoV-2 Omicron infection among patients with systemic autoimmune rheumatic diseases

OBJECTIVES: The surge of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant Omicron infections has affected most Chinese residents at the end of 2022, including a number of patients with systemic autoimmune rheumatic diseases (SARDs). METHODS: To investigate the antibody level of the Omicron variant in SARD patients after SARS-CoV-2 Omicron infection, we tested BA.5.2 and BF.7 Omicron variant IgG antibody levels using ELISA on blood samples collected from 102 SARD patients and 19 healthy controls (HCs). The type of SARD, demographics, concurrent treatment, doses of SARS-CoV-2 vaccines and outcomes were also recorded. RESULTS: A total of 102 SARD patients (mean age: 40.3 years; 89.2% female), including 60 SLE, 32 RA and 10 other SARDs, were identified. Of these, 87 (85.3%) were infected with SARS-CoV-2. We found that the BA.5.2 and BF.7 antibody levels of infected SARD patients were lower than those of HCs (P < 0.05). Sixty-five (63.7%) patients had at least one dose of a SARS-CoV-2 vaccine. SARD patients with at least two doses of SARS-CoV-2 vaccine had a higher level of BA.5.2 and BF.7 antibodies than the unvaccinated group (P < 0.05). There was no evidence for a significant inhibitory effect of glucocorticoids (GCs) on the BA.5.2 and BF.7 Omicron variant antibody levels in SARD patients. SLE patients using biologic DMARDs had a lower BA.5.2 Omicron variant antibody level than patients using GCs and/or HCQ. CONCLUSION: These data suggest that patients with SARDs had a lower antibody response than HCs after Omicron infection.