INTERLEUKIN-1-BETA AND STROMELYSIN (MMP3) ACTIVITY OF SYNOVIAL-FLUID AS POSSIBLE MARKERS OF OSTEOARTHRITIS IN THE TEMPOROMANDIBULAR-JOINT

Purpose: This study investigated the early signs of synovitis and cart ilage degradation by means of synovial fluid analysis in temporomandib ular joints (TMJs) with internal derangement (closed lock) or osteoart hritis (OA), Patients and Methods: Synovial fluid was obtained from 25 TMJs in 22 patients diagnosed with closed lock and from 15 asymptomat ic TMJs of 12 normal controls. IL-1 beta concentrations were measured using enzyme-linked immunosorbent assay (ELISA), and proteinase activi ty was detected by means of gelatin enzymography. Results, Nine of the 25 TMJs with closed lock (CL group) exhibited osteolytic changes on t he surface of the condyle, TMJs in the normal control group did not sh ow any bony changes. Mean IL-1 beta concentration in the synovial flui d (SF) protein in the CL group was 330.1 +/- 347.7 pg per 100 mu g pro tein, which was significantly higher than in the normal control (76.7 +/- 95.3 pg/100 mu g SF-protein), Synovial fluid from the TMJs with os teolytic changes contained higher levels of IL-1 beta (531.8 +/- 379.6 pg/100 mu g SF-protein) than those without bony changes (216.7 +/- 28 0.1 pg/100 mu g SF-protein), Matrix metalloproteinase (MMP) activity w ith a molecular weight of 50 kd (stromelysin or MMP3) was detected in a highly augmented form in two synovial fluid samples of seven closed lock patients, Conclusion, The results suggest that IL-1 beta levels i n synovial fluid of the TMJ have a positive correlation with OA change . The MMP3 activity detected was greatly increased in patients with ca rtilage degradation, These findings suggest that both changes may be i mportant markers of early bone deterioration in TMJs that are undetect able by radiograph imaging.