Table 1 Patient characteristics a
Characteristics | Symptom-free controls | ACPA-negative arthralgia | ACPA-negative RA |
|---|---|---|---|
(n = 19) | (n = 64) | (n = 20) | |
Mean age, yr (SD) | 46.2 (11.8) | 41.9 (14.3) | 58.7 (14.5) |
Females, n (%) | 15 (78.9) | 46 (71.9) | 11 (55.0) |
Positive family history of RA, n (%) | N/A | 25 (39.1) | 4 (20.0) |
Median symptom duration at time of inclusion, wk (IQR) | N/A | 13.4 (8.4 to 26.4) | 17.6 (11.5 to 25.9) |
Gradual symptom onset, n (%) | N/A | 48 (75.0) | 12 (60.0) |
Initial symptom localization, n (%) | N/A | ||
Upper extremities, n (%) | 47 (73.4) | 10 (50.0) | |
Lower extremities, n (%) | 2 (3.1) | 4 (20.0) | |
Upper and lower extremities, n (%) | 15 (23.4) | 6 (30.0) | |
Symmetrical localization, n (%) | N/A | 46 (71.9) | 13 (65.0) |
Median morning stiffness, min (IQR) | N/A | 45 (15 to 90) | 120 (30 to 120) |
Median tender joint count in 68 joints (IQR) | 0 | 5.5 (3 to 10.8) | 12 (4.8 to 17.8) |
Median swollen joint count 66 joints (IQR) | 0 | 0 | 6 (4 to 11) |
ACPA positivity (>7.0 IU/ml), n (%) | N/A | 0 | 0 |
IgM RF positivity (>3.5 IU/ml), n (%) | N/A | 9 (14.1) | 3 (15.0) |
Increased CRP level (>10 mg/L), n (%) | N/A | 10 (15.6) | 11 (55.0) |