Age related alteration in levels of keratan sulfate in sera of orthopaedic patients.

Using the monoclonal antibody to the keratan sulfate(KS), we modified the assay system for detecting of serum KS levels (Thonar, et al. Arthritis Rheum. 28:1367-1376, 1985). This method is based on the enzyme-linked immunosorbent assay (ELISA). The dogfish KS was most effective and sensitive, in this system. KS levels were measured in 45 patients with no complaints of arthralgia, no history of arthritis and no remarkable change in the laboratory data, including erythrocyte sedimentation rates, rheumatoid factor, uric acid and C-reactive protein. Age related changes were apparent in serum levels of KS. Age related catabolism in normal articular cartilage and serum KS levels will aid to estimate the turnover of articular proteoglycan.