Table 1.
Baseline characteristics of seronegative rheumatoid arthritis with or without radiographic damage.
| Total Patients with Seronegative RA (N = 116) | Patients with Radiographic Damage (N = 43, (37.1%)) | Patients without Radiographic Damage (N = 73 (62.9%)) | p | |
|---|---|---|---|---|
| Sex (%) | 0.56 | |||
| Male | 30 (25.9) | 10 (23.3) | 20 (27.6) | |
| Female | 86 (74.1) | 33 (76.7) | 53 (72.6) | |
| Age at diagnosis (yrs; mean ± SD) | 48 ± 12.2 | 47.9 ± 11.7 | 49.1 ± 12.6 | 0.60 |
| Symptoms duration at diagnosis (yrs; mean ± SD) | 1.3 ± 2.1 | 1.3 ± 2.4 | 1.2 ± 1.9 | 0.89 |
| Follow-up duration (yrs; mean ± SD) | 5.2 ± 4.0 | 8.5 ± 4.7 | 4.5 ± 3.4 | 0.02 |
| Past history (%) | ||||
| Diabetes mellitus | 11 (9.6) | 2 (4.7) | 9 (12.3) | 0.28 |
| Hypertension | 14 (12.1) | 6 (14.0) | 8 (11.0) | 0.42 |
| Pulmonary tuberculosis | 3 (2.6) | 2 (4.7) | 1 (1.4) | 0.55 |
| Hepatitis | 5 (4.3) | 1 (2.3) | 4 (5.5) | 0.65 |
| Smoking (%) | 20/87 (23.0) | 6/34 (17.6) | 14/53 (26.4) | 0.43 |
| Morning stiffness at diagnosis (%) | 92 (79.2) | 33 (76.7) | 60 (82.2) | 0.48 |
| Active synovitis at diagnosis (%) | 109 (94.0) | 40 (93.0) | 69 (94.5) | 0.71 |
| Number of joints with active synovitis | 7.4 ± 6.8 | 8.1 ± 7.7 | 7.9 ± 6.4 | 0.41 |
| Distribution of active synovitis | 0.29 | |||
| Small joints only | 43 (37.1) | 11 (25.6) | 32 (43.8) | |
| Large joint only | 23 (19.8) | 9 (20.9) | 14 (19.2) | |
| Small + Large joints | 40 (34.5) | 18 (41.9) | 22 (30.1) | |
| ESR at diagnosis (mm/hr) | 32.9 ± 28.8 | 32.5 ± 29.3 | 32.2 ± 28.2 | 0.89 |
| CRP at diagnosis (mg/dL) | 1.6 ± 2.5 | 1.6 ± 2.1 | 1.5 ± 2.6 | 0.95 |
| Joint erosion at diagnosis (%) | 14 (12.1) | 14 (32.6) | 0 (0) | <0.001 |
| Number of joints with erosion (%) | 2.2 ± 1.9 | 2.2± 1.9 | ||
| Distribution of erosion (%) | ||||
| Small joints only | 11 (78.6) | 11 (78.6) | ||
| Hand 1 joints only | 9 (64.3) | 9 (64.3) | ||
| Foot 2 joints only | 0 (0) | 0 (0) | ||
| Hand + foot joints | 2 (14.3) | 2 (14.3) | ||
| Large 3 joint only | 1 (7.1) | 1 (7.1) | ||
| Elbow | 1 (7.1) | 1 (7.1) | ||
| Small + large joints | 2 (14.3) | 2 (14.3) | ||
| Hand and/or foot + large joints | 2 (14.3) | 2 (14.3) | ||
| Sharp van der Heijde score at diagnosis (mean ± SD) | 6.8 ± 19.4 | 36.7 ± 9.8 | 0 ± 0 | <0.001 |
Except where indicated otherwise, values are the number (%) of variables. N, number; yrs, years; SD, standard deviation; ESR, erythrocyte sedimentation rate; CRP, C-reactive protein. 1 Hand joint included proximal interphalangeal (PIP), metacarpophalangeal (MCP), 1st interphalangeal (IP) joints of hands and wrist joints. 2 Foot joint included metatarsophalangeal and 1st IP joints of feet. 3 Large joint included elbow, ankle, knee, hip, and shoulder joints.