Comparative analysis of clinical features in inflammatory joint diseases with onset after SARS-CoV-2 infection or COVID-19 vaccine administration
| Post-COVID-19 (n=64) | Post-vaccine (n=54) | P value | |
| Age, years | 49±14 | 51±13 | 0.277 |
| Female sex, n (%) | 47 (73.4) | 37 (68.5) | 0.557 |
| N° vaccine doses, n | 2±1 | 3±1 | 0.434 |
| ESR (baseline), mm/h | 32±22 | 36±25 | 0.364 |
| ESR (follow-up), mm/h | 19±12 | 20±14 | 0.689 |
| CRP (baseline), mg/dL | 1.29 (1.00–2.50) | 1.50 (0.56–2.50) | 0.639 |
| CRP (follow-up), mg/dL | 0.53 (0.40–0.90) | 0.50 (0.30–0.80) | 0.456 |
| TJC (baseline), n | 6±4 | 8±6 | 0.081 |
| TJC (follow-up), n | 3±3 | 3±4 | 0.895 |
| SJC (baseline), n | 2 (2–4) | 3 (2–4) | 0.754 |
| SJC (follow-up), n | 0 | 0 | 0.575 |
| DAS28-CRP (baseline), score | 4.3±1.0 | 4.4±1.1 | 0.501 |
| DAS28-CRP (follow-up), score | 3.0±1.0 | 3.1±1.1 | 0.887 |
| Average follow-up, weeks | 8 (6–12) | 8 (7–12) | 0.866 |
| Specific diseases | |||
| pSpA (other than PsA), n (%) | 32 (50.0) | 19 (35.2) | 0.106 |
| HLA-B27 present, n (%) | 8 (25) | 6 (31.6) | 0.748 |
| Enthesitis, n (%) | 4 (12.5) | 1 (5.3) | 0.401 |
| Dactylitis, n (%) | 3 (9.4) | 1 (5.3) | 0.597 |
| RA, n (%) | 19 (29.7) | 14 (25.9) | 0.650 |
| RF positive, n (%) | 11 (57.9) | 10 (71.4) | 0.486 |
| ACPA positive, n (%) | 10 (52.6) | 7 (50.0) | 1.000 |
| PsA, n (%) | 8 (12.5) | 16 (29.6) | 0.021 |
| Enthesitis, n (%) | 3 (37.5) | 8 (50.0) | 0.562 |
| Dactylitis, n (%) | 1 (12.5) | 4 (25.0) | 0.477 |
| AxSpA, n (%) | 5 (7.8) | 3 (5.6) | 0.627 |
| HLA-B27 present, n (%) | 3 (60.0) | 2 (66.7) | 1.000 |
| Enthesitis, n (%) | 1 (20.0) | 0 (0.0) | 0.408 |
| Dactylitis, n (%) | 0 (0.0) | 0 (0.0) | 1.000 |
| AOSD, n (%) | 0 (0.0) | 2 (3.7) | 0.120 |
| Treatment | |||
| Paracetamol, n (%) | 8 (12.5) | 13 (24.1) | 0.101 |
| NSAIDs, n (%) | 30 (46.9) | 22 (40.7) | 0.504 |
| GCs, n (%) | 33 (51.6) | 33 (61.1) | 0.298 |
| Intra-articular GCs, n (%) | 1 (1.6) | 3 (5.6) | 0.232 |
| Colchicine, n (%) | 2 (3.1) | 0 (0.0) | 0.190 |
| MTX, n (%) | 22 (34.4) | 22 (40.7) | 0.476 |
| SSZ, n (%) | 9 (14.1) | 3 (5.6) | 0.128 |
| HCQ, n (%) | 4 (6.3) | 5 (9.3) | 0.540 |
| TNFi, n (%) | 3 (4.7) | 0 (0.0) | 0.107 |
| ANR, n (%) | 0 (0.0) | 1 (1.9) | 0.274 |
ANR, anakinra; AOSD, adult-onset Still’s disease; AxSpA, axial spondyloarthritis; CRP, C reactive protein; DAS28, disease activity score including 28 joints; ESR, erythrocyte sedimentation rate; GCs, glucocorticoids; HCQ, hydroxychloroquine; MTX, methotrexate; NSAIDs, non-steroidal anti-inflammatory drugs; PsA, psoriatic arthritis; pSpA, peripheral spondyloarthritis; RA, rheumatoid arthritis; SJC, swollen joint count; TJC, tender joint count; TNFi, TNF inhibitors.