SERUM PHOSPHOLIPASE-A2 ACTIVITY IN OSTEOA RTHRITIS

Serum phospholipase A2 activity in 67 osteoarthritis patients and 17 c ontrols was determined using a radiolabeled specific substrate. Serum phospholipase A2 activity was significantly higher in osteoarthritis p atients (115 +/- 73.6 dpm/h/ml) than in controls (45 +/- 25 dpm/h/ml) (p=0.002). In 41 osteoarthritis patients, serum phospholipase A2 activ ity was unrelated to age, time since onset of osteoarthritis symptoms, duration of morning stiffness, Lequesne's index, roentgenographic sta ge of osteoarthritis, number of joints with osteoarthritis, erythrocyt e sedimentation rate, or serum C-reactive protein levels. In 12 osteoa rthritis patients who were evaluated twice at a mean interval of 46 da ys, changes in serum phospholipase A2 activity were unrelated to chang es in Lequesne's index. Blind evaluation of long-term joint space loss was performed in 14 patients; serum phospholipase A2 activity increas ed only in those patients with progressive joint space loss, but the d ifference was not statistically significant as compared with the contr ols. These data suggest that serum phospholipase A2 activity is not us eful in practice as a marker for osteoarthritis.