Table 3.
Univariate 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 (NAbs 6 months after second dose of Sinovac-CoronaVac vaccination (D210)
| Patients without SP (anti-S1/S2 IgG) (n = 396) | Patients with SP (anti-S1/S2 IgG) (n = 560) | p-value | Patients without Nab (n = 599) | Patients with Nab (n = 357) | p-value | |
|---|---|---|---|---|---|---|
| Demographic data | ||||||
| Current age, years | 53 (42–63) | 50 (39–60) | 0.001 | 52 (40–62) | 51 (40–60) | 0.382 |
| Current age ≥60 years | 128 (32.3) | 153 (27.3) | 0.094 | 182 (30.4) | 99 (27.7) | 0.384 |
| Male sex | 115 (29.0) | 116 (20.7) | 0.007 | 155 (25.9) | 76 (21.3) | 0.219 |
| Caucasian race | 214 (54.0) | 281 (50.2) | 0.239 | 309 (51.6) | 186 (52.1) | 0.878 |
| ARD | ||||||
| RA | 140 (35.4) | 136 (24.3) | <0.001 | 184 (30.7) | 92 (25.8) | 0.102 |
| SpA | 52 (13.1) | 69 (12.3) | 0.711 | 81 (13.5) | 40 (11.2) | 0.297 |
| PsA | 41 (10.4) | 55 (9.8) | 0.787 | 63 (10.5) | 33 (9.2) | 0.526 |
| SLE | 80 (20.2) | 158 (28.2) | 0.005 | 134 (22.4) | 104 (29.1) | 0.019 |
| Systemic vasculitis | 27 (6.8) | 34 (6.1) | 0.642 | 39 (6.5) | 22 (6.2) | 0.818 |
| IIM | 18 (4.5) | 25 (4.5) | 0.952 | 23 (3.8) | 20 (5.6) | 0.203 |
| SSc | 10 (2.5) | 31 (5.5) | 0.024 | 23 (3.8) | 18 (5.0) | 0.375 |
| SS | 12 (3.0) | 29 (5.2) | 0.106 | 25 (4.2) | 16 (4.5) | 0.820 |
| PAPS | 16 (4.0) | 23 (4.1) | 0.959 | 27 (4.5) | 12 (3.4) | 0.715 |
| Current therapies | ||||||
| Hydroxychloroquine | 93 (23.5) | 185 (33.0) | 0.001 | 167 (27.9) | 111 (31.1) | 0.290 |
| Sulfasalazine | 42 (10.6) | 44 (7.9) | 0.143 | 63 (10.5) | 23 (6.4) | 0.033 |
| Prednisone | 173 (43.7) | 174 (31.1) | <0.001 | 225 (37.6) | 122 (34.2) | 0.292 |
| Prednisone dose | 5 (5–10) | 7.5 (5–10) | 0.043 | 5 (5–10) | 7.5 (5–10) | 0.131 |
| Prednisone >10 mg/day | 22 (12.7) | 32 (18.4) | 0.145 | 29 (12.9) | 25 (20.5) | 0.062 |
| Prednisone >20 mg/day | 4 (2.3) | 6 (3.4) | 0.750 | 6 (2.7) | 4 (3.3) | 0.746 |
| Immunosuppressive | 255 (64.4) | 338 (60.4) | 0.205 | 368 (61.4) | 225 (63.0) | 0.624 |
| Methotrexate | 105 (26.5) | 144 (25.7) | 0.781 | 153 (25.5) | 96 (26.9) | 0.646 |
| Leflunomide | 62 (15.7) | 71 (12.7) | 0.190 | 86 (14.4) | 47 (13.2) | 0.606 |
| Mycophenolate mofetil | 53 (13.4) | 72 (12.9) | 0.812 | 73 (12.2) | 52 (14.6) | 0.291 |
| Azathioprine | 38 (9.6) | 63 (11.2) | 0.412 | 60 (10.0) | 41 (11.5) | 0.475 |
| Tofacitinib | 9 (2.3) | 14 (2.5) | 0.821 | 14 (2.3) | 9 (2.5) | 0.858 |
| Cyclophosphamide | 1 (0.3) | 6 (1.1) | 0.250 | 5 (0.8) | 2 (0.6) | 0.630 |
| Biologic agent | 179 (45.2) | 165 (29.5) | <0.001 | 231 (38.6) | 113 (31.7) | 0.031 |
| Anti-TNF | 76 (19.2) | 74 (13.2) | 0.012 | 102 (17.1) | 48 (13.4) | 0.141 |
| Abatacept | 39 (9.8) | 15 (2.7) | <0.001 | 42 (7.0) | 12 (3.4) | 0.018 |
| Tocilizumab | 20 (5.1) | 32 (5.7) | 0.656 | 28 (4.7) | 24 (6.7) | 0.177 |
| Belimumab | 16 (4.0) | 15 (2.7) | 0.242 | 19 (3.2) | 12 (3.4) | 0.873 |
| Rituximab | 12 (3.0) | 6 (1.1) | 0.028 | 14 (2.3) | 4 (1.1) | 0.181 |
Results are expressed in median (interquartile range) and n (%). Continuous data were compared using Mann–Whitney test, and categorical variables with the chi-square or Fisher’s exact tests, as appropriate, always as two-sided analyses, without adjustments for multiple comparisons. 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.