OPN levels by Steinbrocker stage in patients with RA.
| Levels of OPN, median (range) | Stage I | Stage II | Stage III | Stage IV |
|---|---|---|---|---|
| U-half, pmol/mmol Cr | 98.6 (5.9–380.8) | 116.5 (16.7–1311.1) | 249.9 (83.1–548.2)* | 251.6 (29.1–2431.8)* |
| U-full, ng/mmol Cr | 1375.1 (95.0–6445.4) | 2248.1 (54.8–8055.5) | 2574.0 (430.4–5827.3) | 1785.9 (90.1–4498.0) |
| P-full, ng/ml | 436.8 (58.8–1492.8) | 475.2 (286.2–1294.3) | 479.5 (259.6–1317.6) | 521.1 (220.4–769.3) |
↵* p < 0.05 compared to Stage I. OPN: osteopontin; U-half: thrombin-cleaved OPN in urine; U-full: full-length form of OPN in urine; P-full: full-length form of OPN in plasma.