Clinical, demographic, serologic, and therapeutic characteristics of patients with pure palindromic rheumatism (PR) according to ACPA positivity or negativity.
| Characteristics | PR, n = 54 | PR-ACPA+, n = 36 | RP-ACPA–, n = 18 | p |
|---|---|---|---|---|
| Age, yrs, mean ± SD | 51.2 ± 11.3 | 48.6 ± 8.6 | 56.2 ± 14.4 | 0.04 |
| Age at onset of PR, yrs, mean ± SD | 39.7 ± 11.4 | 39.4 ± 10.4 | 40.4 ± 13.4 | 0.7 |
| Female, n (%) | 34 (63) | 23 (63.9) | 11 (61.1) | 0.8 |
| Disease duration, yrs, mean ± SD | 11.6 ± 10.7 | 9.5 ± 7.6 | 15.8 ± 14.5 | 0.09 |
| Current smoker, n (%) | 17 (31.5) | 12 (33.3) | 5 (27.8) | 0.4 |
| Frequency of attacks, n (%) | ||||
| > 1 month | 6 (11.1) | 5 (13.9) | 1 (5.6) | 0.6 |
| ≥ 1 week | 11 (20.4) | 9 (25) | 2 (11.1) | 0.3 |
| Attack duration, h, mean ± SD, n (%) | ||||
| ≤ 72 h | 47 (87) | 34 (94.4) | 13 (72.2) | 0.02 |
| > 72 h, < 1 week | 7 (13) | 2 (5.6) | 5 (27.8) | 0.02 |
| Oligoarticular attacks, n (%) | 17 (31.5) | 12 (33.3) | 5 (27.8) | 0.7 |
| No. affected joints, mean ± SD | 6.1 ± 2.1 | 6.28 ± 2.2 | 5.72 ± 1.9 | 0.4 |
| Joint involvement during PR course, n (%) | ||||
| PIP | 48 (88.9) | 32 (88.9) | 16 (88.9) | 1 |
| Wrist | 46 (85.2) | 32 (88.9) | 14 (77.8) | 0.3 |
| MCP | 45 (83.3) | 31 (86.1) | 14 (77.8) | 0.4 |
| Shoulder | 44 (81.5) | 31 (86.1) | 13 (72.2) | 0.2 |
| Knee | 42 (77.8) | 27 (75) | 15 (83.3) | 0.5 |
| RF+, n (%) | 31 (57.4) | 27 (75) | 4 (22.2) | 0.01 |
| ANA+, n (%) | 18 (33) | 14 (38.9) | 4 (22.2) | 0.2 |
| CRP, mg/dl, mean ± SD | 0.35 ± 0.4 | 0.38 ± 0.3 | 0.29 ± 0.54 | 0.4 |
| ESR, mm/h, mean ± SD | 12.5 ± 9.7 | 12.1 ± 10.7 | 13.3 ± 7.7 | 0.6 |
| DMARD treatment | ||||
| At the time of assessment | 33 (61.1) | 25 (69.4) | 8 (44.4) | 0.08 |
| Hydroxychloroquine | 20 (37) | 16 (44.4) | 4 (22.2) | 0.1 |
| Methotrexate | 6 (11) | 6 (16.7) | 0 | 0.2 |
| Leflunomide | 4 (7.4) | 4 (12.9) | 0 | 0.3 |
| Others | 5 (9.3) | 3 (8.3) | 2 (11.1) | 0.3 |
| During past PR course | 46 (85.2) | 32 (88.9) | 14 (77.8) | 0.3 |
PIP: proximal interphalangeal; MCP: metacarpophalangeal; RF: rheumatoid factor; ANA: antinuclear antibody; ACPA: anticitrullinated protein antibodies; CRP: C-reactive protein; ESR: erythrocyte sedimentation rate; DMARD: disease-modifying antirheumatic drugs.