QUANTITATION OF CHONDROITIN-4-SULFATE AND CHONDROITIN-6-SULFATE IN PATHOLOGICAL 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 (DELTAdi-4S) and chondroitin 6-sulfate (DELTAdi-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 DELTAdi-4S and DELTAdi-6S produced were determined by high performance liquid chromatography combined with fluorometry. Results. Total content of DELTAdi-4S plus DELTAdi-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 DELTAdi-6S to DELTAdi-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 DELTAdi-6S: DELTAdi-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.