ASSESSMENT OF URINARY HYDROXYPYRIDINIUM CROSS-LINKS MEASUREMENT IN OSTEOARTHRITIS

The aim of this study is to re-evaluate urinary collagen cross-links, previously proposed as markers of osteoarthritis (OA). The urinary exc retion of collagen cross-links, pyridinoline (PYD) and deoxypyridinoli ne (DPD), was measured using high-performance liquid chromatography (H PLC) in 114 patients with OA, 19 patients with rheumatoid arthritis (R A) and 40 healthy subjects. An increase in PYD and DPD, expressed per millimole of creatinine, was confirmed in RA. However, PYD and DPD in patients with hip OA; knee OA and polyOA were similar, and did not dif fer from controls. In patients with radiographic end-stage OA, PYD and DPD were significantly higher than in patients with an early OA, but not significantly higher than in controls. The PYD/DPD ratio did not v ary with the OA stage. Thus, urinary collagen cross-links are not elev ated in OA, but could reflect bone sclerosis and/or erosion in late OA .