Table 4.

Multivariate analyses of characteristics of autoimmune rheumatic diseases (ARD) patients without and with seropositivity (SP) for anti-SARS-CoV-2 S1/S2 IgG antibodies and without and with neutralizing antibodies (NAb) 6 months after second dose of Sinovac-CoronaVac vaccination (D210)

	Anti-S1/S2 IgG seropositivity			NAb positivity
	OR	95% CI	p-value	OR	95% CI	p-value
Demographic data
Current age, years	0.99	0.98–1.0	0.053	—	—	—
Male sex	0.56	0.40–0.79	<0.001	—	—	—
ARD
RA	0.92	0.62–1.36	0.667	0.98	0.70–1.37	0.911
SLE	0.97	0.59–1.57	0.886	1.21	0.87–1.69	0.265
SSc	1.57	0.73–3.38	0.248	—		—
Current therapies
Hydroxychloroquine	1.25	0.83–1.89	0.282	—		—
Sulfasalazine	1.03	0.64–1.67	0.891	0.65	0.39–1.09	0.101
Prednisone	0.56	0.41–0.76	<0.001	—		—
Leflunomide	1.04	0.69–1.57	0.850	—		—
Biologic agent
Anti-TNF	0.66	0.45–0.96	0.031	0.80	0.54–1.19	0.271
Abatacept	0.29	0.15–0.56	<0.001	0.48	0.24–0.97	0.041
Tocilizumab	—	—	—	1.55	0.83–2.91	0.174
Rituximab	0.32	0.11–0.90	0.031	0.45	0.15–1.38	0.161

Results are expressed in OR (95% CI) regarding the positivity for anti-S1/S2 IgG and for NAb. Adjusted analyses included the factors with p > 0.20 at unadjusted analyses, depicted in Table 3, using multiple logistic regression models.SP—seropositivity (IgG titer ≥ 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 was defined as a neutralizing activity ≥30% (cPass sVNT Kit, GenScript, Piscataway, USA).

RA rheumatoid arthritis, SpA spondyloarthritis, PA psoriatic arthritis, SLE systemic lupus erythematosus, IIM idiopathic inflammatory myopathy, SSc systemic sclerosis, SS Sjögren’s syndrome, PAPS primary antiphospholipid syndrome.