The effect of chemonucleolysis on serum keratan sulfate levels in humans.

Sensitive measurements of serum keratan sulfate (KS), a glycosaminoglycan found in large quantities in the proteoglycans of human cartilage, can be obtained using an enzyme-linked immunosorbent-inhibition assay. Patients who are undergoing chemonucleolysis (CN) provide a clinical opportunity to monitor the large-scale proteolytic degradation of cartilage. By measuring serum KS levels both pre- and post-CN, we have demonstrated that serum KS levels rise predictably after CN, in a manner that reflects major catabolic events of cartilage.