Table 4.
Unadjusted logistic regression models examining the factors associated with positive anti-S1/S2 IgG antibodies and NAb after 2 doses of CoronaVac (at D69) in spondylarthritis (SpA) patients with no DMARD and no prednisone (n = 28) or with DMARD monotherapy (n = 86).
| Anti-SARS-CoV-2 S1/S2 IgG SC |
Neutralising antibodies (NAb) |
|||
|---|---|---|---|---|
| OR | 95% CI | OR | 95% CI | |
| Demographic data | ||||
| Current age (each 5 years interval) | 0.75 | (0.54–1.04) | 0.93 | (0.78–1.12) |
| Current age > 60 years, n = 41 | 1.91 | (0.57–6.38) | 0.77 | (0.35–1.69) |
| Female sex, n = 36 | 0.42 | (0.12–1.40) | 0.66 | (0.29–1.50) |
| Caucasian ethnicity, n = 69 | 0.74 | (0.21–2.63) | 0.63 | (0.28–1.41) |
| SpA | ||||
| AS, n = 75 | 2.09 | (0.63–6.98) | 1.75 | (0.78–3.89) |
| PsA, n = 39 | 0.48 | (0.14–1.60) | 0.57 | (0.26–1.28) |
| Disease activity | ||||
| ASDAS-CRP | 0.96 | (0.43–2.12) | 1.18 | (0.65–2.12) |
| BASDAI | 1.12 | (0.65–1.94) | 0.86 | (0.58–1.25) |
| DAPSA | 1.02 | (0.89–1.17) | 1.02 | (0.92–1.13) |
| PASI | 1.95 | (0.46–8.28) | 0.86 | (0.62–1.19) |
| Current therapies | ||||
| No DMARD or prednisone, n = 28 | 9.56 | (0.55–166.92) | 2.40 | (0.88–6.52) |
| Sulfasalazine, n = 19 | 5.84 | (0.33–102.91) | 3.40 | (0.93–12.49) |
| Immunosuppressive drugs | ||||
| Methotrexate, n = 16 | 0.44 | (0.10–1.83) | 0.65 | (0.22–1.91) |
| Leflunomide, n = 2 | 0.62 | (0.03–13.71) | 0.53 | (0.03–8.78) |
| Biologic therapy | ||||
| TNFi, n = 40 | 0.15 | (0.04–0.57)** | 0.37 | (0.17–0.83)* |
| Secukinumab, n = 8 | 2.25 | (0.12–41.39) | 0.89 | (0.20–3.95) |
Results are expressed in OR (95% CI) regarding the positivity for anti-S1/S2 IgG and for Nab. Seropositivity defined as a positive serology (IgG titre ≥ 15 AU/mL) for anti-SARS-CoV-2 S1/S2 IgG antibodies after vaccination (Indirect ELISA, LIAISON® SARS-CoV-2 S1/S2 IgG, DiaSorin, Italy). Positivity for NAb defined as a neutralising activity ≥ 30% (cPass sVNT Kit, GenScript, Piscataway, USA); AxSpA: axial spondyloarthritis (non-radiographic spondyloarthritis and ankylosing apondylitis); PsA: psoriatic arthritis; ASDAS-CRP: ankylosing spondylitis disease activity score-C reactive protein; BASDAI: Bath ankylosing spondylitis disease activity index; DAPSA: disease activity in psoriatic arthritis; PASI: psoriasis area severity index; NSAID: Non-steroidal anti-inflammatory drugs; TNFi: tumor necrosis factor inhibitor.
P < 0.05.
P < 0.01.