Objective: To investigate the hypothesis that concentrations of the keratan sulfate epitope, 1/20/5D4 (5D4) and total sulfated glycosaminoglycans (S-GAG) in synovial fluids, and of 5D4 in serum of dogs with naturally acquired osteoarthritis of the genual joint (stifle), secondary to cranial cruciate ligament deficiency, are associated with other disease parameters of osteoarthritis.
Animals: 58 dogs with stifle osteoarthritis secondary to naturally acquired cranial cruciate ligament (CCL) deficiency.
Procedure: All dogs were examined clinically, radiographically and, in some instances, scintigraphically. Serum and synovial fluid from both stifles were assayed for 5D4 concentration, using an inhibition ELISA, and for S-GAG, using a direct dye-binding assay.
Results: Serum 5D4 concentration was not significantly associated with other disease features. Total S-GAG values were high, and 5D4 values were low, in synovial fluid from clinically active, compared with contralateral joints. The S-GAG concentration in synovial fluid from clinically active joints was negatively correlated with radiographic severity score (rs = -0.389, P = 0.004, Spearman's rank correlation). Other associations between marker concentrations and disease parameters could not be detected.
Conclusions: Serum 5D4 concentration is not a useful marker of stifle osteoarthritis in dogs; however, synovial fluid S-GAG and 5D4 values may hold more promise as disease measures.