Pyridinoline (Pyr) and deoxypyridinoline (Dpyr) collagen cross-links are known markers of bone and cartilage turnover that are found in urine in various diseases. The present study was designed to quantify Pyr and Dpyr levels in urine of patients with osteoarthritis (OA) of the temporomandibular joint (TMJ), and to evaluate whether their concentrations are related to specific pathologic findings in the TMJ.
Urine samples were obtained from 12 patients with OA of the TMJ and 16 asymptomatic controls, and following appropriate preparation, analyzed by high-performance liquid chromatography (HPLC) and fluorescence spectroscopy for Pyr and Dpyr.
The urinary concentration of Pyr and the Pyr to Dpyr (Pyr/Dpyr) ratio were significantly higher (P < 0.05) in OA patients than in the controls (182.2 +/- 86.5 pmol/ml vs. 115.6 +/- 27.9 pmol/ml and 4.00 +/- 1.53 pmol/ml vs. 2.86 +/- 0.97 pmol/ml, respectively). However, the Pyr/Dpyr ratio was not associated with any specific clinical or radiographic findings.
These findings suggest that the level of Pyr and the Pyr/Dpyr ratio in urine may be a useful diagnostic indicator for intra-articular pathologic changes during TMJ OA.