Utility of urinary pyridinoline and deoxypyridinoline ratio for diagnosis of osteoarthritis at temporomandibular joint.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Coagulase-negative staphylococcal membrane-damaging toxins, pain intensity, and metabolic changes in temporomandibular disorder patients with chronic muscle pain.

AIMS: To investigate the association between toxin-producing staphylococci, symptom expression, and changes in urinary excretion of metabolites in temporomandibular disorder (TMD) patients and age- and sex-matched control subjects. METHODS: Twenty-nine patients defined by the research diagnostic criteria/TMD as having Type 1a muscle pain (TMD1A), and 34 age- and sex-matched control subjects were assessed for the carriage of staphylococcal species, staphylococcal toxin production, expression of symptoms, and changes in urinary excretion of amino and organic acids. RESULTS: TMD1A patients had an increased incidence of carriage of toxin-producing coagulase-negative staphylococcus (MDT-CoNS, P < .004), which produced increased levels of delta-like membrane-damaging toxins. The TMD1A patients also had a reduction in the incidence of carriage of Staphylococcus aureus (P < .02). Increased incidence of MDT-CoNS was positively associated with increased pain intensity as assessed by a visual analog scale (P < .001). Odds ratio analysis revealed a 9.2-fold increase in MDT-CoNS recovery from the nose of TMD1A patients compared with the control subjects (odds ratio = 9.2, > 95% confidence limits: 2.3 to 37.5, P < .001). Increases in the carriage incidence of MDT-CoNS were also associated with increases in the urinary tyrosine:leucine ratio (P < .004), which represents a change in the balance of proteolysis and protein synthesis. The toxin production by these CoNS species was also associated with an increased urinary excretion of glutamic acid (P < .03). CONCLUSION: These data suggest that an increased colonization of MDT-CoNS on skin and mucosal membranes was associated with changed proteolysis, increased pain intensity, and an increase in excitatory amino acids consistent with events associated with the development of chronic orofacial muscle pain in TMD patients.

Changes in urinary bone resorption markers (pyridinoline, deoxypyridinoline) resulting from experimentally-induced osteoarthritis in the temporomandibular joint of rats.

The purpose of this study was to quantify the urinary bone resorption markers, pyridinoline (Pyr) and deoxypyridinoline (Dpyr), excreted from experimentally-induced osteoarthritis (OA) in the temporomandibular joint (TMJ) of rats. Osteoarthritic lesions were induced by intra-articular injection of collagenase into the right TMJs of 16-week-old male rats. The whole day's urine was collected from each animal one day before the injection and 5, 7, 11 and 14 days after the injection. Urine samples were analyzed by high-perfomance liquid chromatography and fluorescence spectroscopy. Histological changes in condyle were examined by using paraffin sections with toluidine blue staining. Degenerative changes were observed in the articular cartilage of the experimental group on day 7 and day 14 after the injection of collagenase. The concentration of Pyr was remarkably high in the experimental group, and consequently the Pyr to Dpyr ratio was significantly higher (p<0.05) in the experimental group than in the control group from 7-14 days after the injection. These findings suggest that a urinary Pyr/Dpyr ratio would be available for the detection of degenerative changes in condyle relevant to temporomandibular joint osteoarthritis (TMJ OA).