Increased serum C-reactive protein levels by immuno-nephelometry in patients with rapidly destructive hip osteoarthritis

Objective. To compare serum C-reactive protein levels measured using a high ly sensitive immunonephelometry method in patients with rapidly destructive versus slowly progressive hip osteoarthritis. Methods. Ten patients meetin g criteria for rapidly destructive hip osteoarthritis were compared to 25 p atients with slowly progressive hip osteoarthritis defined as less than 0.2 0 mm joint space loss over the last year. Serum C-reactive protein was assa yed using an immunonephelometry method with a detection threshold of 0.17 m g/L and a coefficient of variation of less than 5%. Results. One patient in each group was excluded because of a C-reactive protein level greater than 15 mg/L. The mean C-reactive protein level in the remaining 33 patients wa s 3.05+/-3.46 mg/L (range, 0.10-14.9 mg/L). Mean C-reactive protein was sig nificantly higher in the rapidly destructive group than in the slowly progr essive group (5.61+/-4.75 versus 1.94+/-1.98 mg/L, P=0.01), even after adju stment for potential confounding factors. Conclusion. Our data suggest that rapidly destructive hip osteoarthritis may be associated with some degree of inflammation reflected by a small but significant increase in serum C-re active protein levels.