Table 2.
Baseline characteristics of ARD patients seropositive and seronegative for IgG/NAb after fourth COVID-19 heterologous vaccination
| Anti-S1/S2 IgG |
NAb |
|||||
|---|---|---|---|---|---|---|
| Seronegative (n = 8) | Seropositive (n = 156) | P-value | Seronegative (n = 27) | Seropositive (n = 137) | P-value | |
| Demographic data | ||||||
| Current age, years | 55.8 (10.7) | 55.6 (12.9) | 0.970 | 61.1 (12.3) | 54.5 (12.6) | 0.015 |
| Current age ≥60 years | 3 (37.5) | 68 (43.6) | >0.99 | 17 (63.0) | 54 (39.4) | 0.024 |
| Female sex | 6 (75.0) | 131 (84.0) | 0.504 | 25 (92.6) | 112 (81.8) | 0.165 |
| White race | 5 (62.5) | 82 (52.6) | 0.724 | 14 (51.9) | 73 (53.3) | 0.892 |
| ARD | ||||||
| RA | 5 (62.5) | 71 (45.5) | 0.473 | 20 (74.1) | 58 (40.9) | 0.002 |
| Axial SpA | 0 | 8 (5.1) | >0.99 | 0 | 8 (5.8) | 0.355 |
| PsA | 0 | 9 (5.8) | >0.99 | 0 | 9 (6.6) | 0.358 |
| SLE | 1 (12.5) | 37 (23.7) | 0.683 | 1 (3.7) | 37 (27.0) | 0.006 |
| Systemic vasculitis | 1 (12.5) | 7 (4.5) | 0.336 | 2 (7.4) | 6 (4.4) | 0.619 |
| Idiopathic inflammatory myopathies | 0 | 8 (5.1) | >0.99 | 0 | 8 (5.8) | 0.355 |
| SSc | 1 (12.5) | 1 (0.6) | 0.095 | 2 (7.4) | 0 | 0.026 |
| Primary SS | 0 | 6 (3.8) | >0.99 | 2 (7.4) | 4 (2.9) | 0.257 |
| Primary APS | 0 | 6 (3.8) | >0.99 | 0 | 6 (4.4) | 0.591 |
| Current therapies | ||||||
| HCQ | 3 (37.5) | 40 (25.6) | 0.433 | 4 (14.8) | 39 (28.5) | 0.159 |
| SSZ | 0 | 10 (6.4) | >0.99 | 1 (3.7) | 9 (6.6) | >0.99 |
| Prednisone | 5 (62.5) | 88 (57.9) | >0.99 | 15 (55.6) | 78 (58.6) | 0.767 |
| Prednisone dose | 7.5 (4.4–12.5) | 5 (5-10) | 0.574 | 7.5 (5–10) | 5 (5-0) | 0.157 |
| Prednisone ≥7.5 mg/day | 3 (37.5) | 31 (19.9) | 0.364 | 9 (33.3) | 25 (18.2) | 0.077 |
| Number of DMARDs | 2 (2–2) | 1 (1–2) | 0.018 | 2 (1–2) | 1 (1–2) | 0.094 |
| Immunosuppressive | 8 (100) | 108 (69.2) | 0.106 | 22 (81.5) | 94 (68.6) | 0.179 |
| MTX | 5 (62.5) | 48 (30.8) | 0.113 | 13 (48.1) | 40 (29.2) | 0.054 |
| LEF | 0 0 | 24 (15.4) | 0.605 | 8 (29.6) | 18 (11.7) | 0.016 |
| AZA | 1 (12.5) | 21 (13.5) | >0.99 | 2 (7.4) | 20 (14.6) | 0.536 |
| MMF | 2 (25.0) | 19 (12.2) | 0.272 | 3 (11.1) | 18 (13.1) | >0.99 |
| Tofacitinib | 0 | 5 (3.2) | >0.99 | 1 (3.7) | 4 (2.9) | >0.99 |
| Tacrolimus | 1 (12.5) | 3 (1.9) | 0.183 | 0 | 4 (2.9) | >0.99 |
| CYC | 0 | 2 (1.3) | >0.99 | 0 | 2 (1.5) | >0.99 |
| Ciclosporin | 0 | 2 (1.3) | >0.99 | 0 | 2 (1.5) | >0.99 |
| Biologic drug | 6 (75.0) | 75 (48.1) | 0.165 | 14 (51.9) | 67 (48.9) | 0.780 |
| Anti-TNF | 0 | 29 (18.6) | 0.353 | 2 (7.4) | 27 (19.7) | 0.170 |
| Abatacept | 2 (25.0) | 17 (10.9) | 0.233 | 6 (22.2) | 13 (9.5) | 0.059 |
| Tocilizumab | 0 | 11 (7.1) | >0.99 | 1 (3.7) | 10 (7.3) | 0.694 |
| Belimumab | 0 | 10 (6.4) | >0.99 | 0 | 10 (7.3) | 0.371 |
| Rituximab | 4 (50.0) | 7 (4.5) | 0.001 | 5 (18.5) | 6 (4.4) | 0.007 |
| Ustekinumab | 0 | 1 (0.6) | >0.99 | 0 | 1 (0.7) | >0.99 |
Results are expressed in mean (s.d.), median (interquartile range) and n (%). Seropositivity for anti-SARS-CoV-2 S1/S2 IgG was defined as post-vaccination titre ≥15 AU/mL by 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, NJ, USA). P < 0.05 are highlighted in bold. ARD: autoimmune rheumatic diseases; NAb: neutralizing antibodies.