Table 2

Baseline predictors of day 42 anti-SARS-CoV-2 RBD IgG titres according to linear regression model

β95% CIP value
Age, years−0.61−2.0 to 0.750.4
Male sex−62−127 to 3.70.064
At least one BILAG score ≥B−45−106 to 170.2
C3, g/L35−77 to 1470.5
dsDNA antibodies, IU/mL0.04−0.06 to 0.130.4
Detectable IFN-α−3.4−7.4 to 0.580.093
Total serum IgA, g/L1.8−12 to 160.8
Total serum IgG, g/L2.00.34 to 3.60.018
Total serum IgM, g/L12−1.0 to 240.071
Lymphocytes count, G/L6.6−31 to 440.7
Corticosteroids low−20−66 to 260.4
Corticosteroids high−50−127 to 280.2
Hydroxychloroquine−27−85 to 310.4
Azathioprine−118−242 to 6.50.063
Belimumab−18−90 to 540.6
Mycophenolate mofetil−78−133 to 220.007
Methotrexate−122−184 to 61<0.001
Other immunosuppressor62−32 to 1560.2
  • SLE activity is measured with BILAG score.

  • *See the Methods section.

  • BILAG, British Isles Lupus Assessment Group; dsDNA, double-stranded DNA; IFN, interferon; IgG, immunoglobulin G; RBD, receptor binding domain.