URINARY HYDROXYPYRIDINIUM CROSS-LINKS OF COLLAGEN IN RHEUMATOID ARTHRITIS. RELATION TO DISEASE ACTIVITY AND EFFECTS OF METHYLPREDNISOLONE

Pyridinoline (Pyr) and deoxypyridinoline (Dpyr) are new markers of type I and II collagen degradation. Dpyr is a specific marker of type I collagen resorption in bone, whereas Pyr is released from type I and II collagen in bone and cartilage. We assessed the effect of six repeated iv methylprednisolone (MP) pulses or placebo at 4 week intervals in combination with DMARDs, on the excretion of Pyr and Dpyr in 86 patients with active RA. Pyr and Dpyr correlated significantly with clinical and biochemical markers of disease activity. After an initial decrease in Pyr on day 7 in the MP treated group, Pyr was significantly increased in both treatment groups at day 28