Table 1 Baseline characteristics of 710 patients with early rheumatoid arthritis or undifferentiated arthritis
Patients with early RA or UA | Early RA | UA | Univariate analysis: P value | Multivariate analysis: OR (95% CI), P value | |
|---|---|---|---|---|---|
(1) | (2) | (1) versus (2) | (1) versus (2) | ||
n = 710 | n = 578 | n = 132 | |||
Percentage of females | 76.5% | 77% | 74% | 0.8 | |
Age, years | 49.0 (40.0–64.0) | 50.1 (42.3–65.2) | 47.4 (39.5–62.4) | 0.6 | |
ESR, mm at 1st hour | 22.0 (11.2–38) | 23.0 (12.0–40.1) | 17.0 (10.0–32.0) | 0.01 | 0.9 (0.9–1.0), 0.6 |
CRP, mg/L | 9.0 (0–24.0) | 9.5 (3.0–25.0) | 6.0 (0–16.0) | 0.002 | 1.0(0.9–1.1), 0.3 |
Positivity for anti-CCP | 40.3% | 47.4% | 13.2% | <0.0001 | 5.8 (3.4–10.0), 0.001 |
BAFF, ng/mL | 0.7 (0.5–1.0) | 0.7 (0.5–1.0) | 0.7 (0.5–0.9) | 0.5 | |
Beta2–microglobulin, mg/L | 1.9 (1.7–2.3) | 2.0 (1.7–2.4) | 1.8 (1.6–2.1) | 0.0002 | 1.5 (1.0–2.0), 0.03 |
Total IgG, g/L | 13.5 (11.5–16.1) | 13.5 (11.7–16.1) | 12.9 (10.9–16.0) | 0.03 | 0.9 (0.9–1.0), 0.4 |
Total IgA, g/L | 2.6 (1.9–3.5) | 2.8 (1.9–3.5) | 2.2 (1.7–3.1) | <0.0001 | 1.2 (0.9–1.5), 0.06 |
Total IgM, g/L | 1.5 (1.1–2.0) | 1.5 (1.1–2.0) | 1.4 (1.1–1.9) | 0.5 | |
Kappa free light chain, mg/L | 13.8 (10.5–17.9) | 14.3 (10.9–18.7) | 11.7 (9.6–14.9) | <0.0001 | 1.0 (0.9–1.0), 0.6 |
Lambda free light chain, mg/L | 16.4 (12.8–21.6) | 17.5 (13.2–22.5) | 14.5 (11.6–18.8) | <0.0001 | 0.9 (0.9–1.0), 0.9 |
Ratio of kappa to lambda | 0.8 (0.3–0.99) | 0.8 (0.7–1.0) | 0.8 (0.7–0.9) | 0.9 |