Quantitation of chondroitin 4-sulfate and chondroitin 6-sulfate in pathologic joint fluid.

OBJECTIVE

To investigate the correlation between joint disease and the composition of chondroitin sulfate in the joint fluid, unsaturated disaccharide isomers of chondroitin 4-sulfate (delta di-4S) and chondroitin 6-sulfate (delta di-6S) were measured in joint fluids obtained from patients with osteoarthritis (OA), rheumatoid arthritis (RA), or traumatic arthritis (TA).

METHODS

These pathologic joint fluids were digested with chondroitinase ABC, and the delta di-4S and delta di-6S produced were determined by high performance liquid chromatography combined with fluorometry.

RESULTS

Total content of delta di-4S plus delta di-6S was 71.8 +/- 30.0 nmoles/ml (mean +/- SD) in OA, 55.4 +/- 29.3 nmoles/ml in RA, and 211 +/- 149 nmoles/ml in TA joint fluids. The ratio of delta di-6S to delta di-4S was 3.81 +/- 0.992 in OA, 1.13 +/- 0.527 in RA, and 5.75 +/- 2.46 in TA joint fluids. Differences between groups were statistically significant.

CONCLUSION

These results strongly suggest that the levels of chondroitin sulfate isomers and the delta di-6S: delta di-4S ratio in joint fluid reflect the proteoglycan metabolism of joint tissues, particularly of articular cartilage; hence, they could be used to diagnose joint diseases and to predict articular cartilage destruction from such joint diseases.