Serum and synovial fluid levels of chondroitin sulfate in patients with osteoarthritis of the knee joint.

Abstract

We measured serum and synovial fluid levels of chondroitin sulfate (CS) in patients with osteoarthritis (OA) of the knee joint to clarify whether CS levels differ in various stages of OA, and whether measurement of CS levels is useful in evaluating the pathology of OA. The study population was 117 OA patients and 23 healthy young volunteers. Synovial fluid was obtained from 69 of 117 OA patients. The mean serum level of C4S in all of the OA patients was significantly higher than that in the controls (p< 0.05). However, there was little difference between respective OA stages. A small amount of serum C6S (0.2 to 0.6 nmol/ml) was detected in 31.6% of the OA patients and in 26.1%of the control subjects. The mean serum C0S level in all OA patients was significantly higher than that in the controls (p< 0.01). However no significant difference was found between respective OA stages. As for synovial fluid CS, the C4S level in the early stage of OA tended to be higher than that in the advanced stage. C6S levels showed a markedly decreasing trend with advancing OA stage. C0S was not detected in synovial fluid. The present study demonstrated that serum levels of C4S and C0S in OA patients are elevated compared with normal subjects, and that synovial fluid levels of C4S and C6S may provide useful in assessing the pathology of OA.