The aim of this study was to determine serum and synovial concentrations of the CS-846 epitope of articular cartilage aggrecan, in horses with a radiological diagnosis of osteochondral fragmentation (OF). For this purpose, 20 thoroughbred horses with unilateral radiocarpal or intercarpal OF were used, and 10 clinically and radiologically healthy Thoroughbred horses were assigned to the control group. Serum and synovial concentrations of the CS-846 epitope were measured in both groups by means of ELISA. The concentration of the CS-846 epitope in synovial fluid was significantly higher in carpal joints with moderate articular damage (grade 2 OF) than in the control group or in horses with severe disease (grade 3 and 4 OF). In serum, non-statistical differences in the concentration of the CS-846 epitope were observed between horses with OF and controls. We conclude that the concentration of CS-846 epitope in synovial fluid suggests an increase in cartilage aggrecan synthesis, which may be associated with the presence of moderate clinical disease. The CS-846 epitope concentration in synovial fluid may be a useful biomarker for the study of carpal OF in horses, providing a measure of the balance between cartilage synthesis and degradation in this equine disease.

SUMMARYLameness associated to joint disease (JD) in athlete equines is an important cause of economic losses. Intensive training produces biomechanical overload of the synovial joints with a consequent activation of metalloproteinases, which have been associated to the pathogenesis of equine JD. This disease is characterized by the degradation of the extracellular matrix (ECM) of the articular cartilage causing the release of structural components of the cartilage matrix to the joint space and producing changes in the synovial fluid concentration of these ECM components, termed biomarkers. The changes in the concentration of some of these proteins in the synovial fluid might be used to evaluate both the onset and progression of equine JD. The measurement of the levels of aggrecan and collagen type II in the synovial fluid using specific monoclonal antibodies is an example of this approach. This review presents an update on biomarkers used for equine JD.Palabras clave: enfermedad articular, biomarcador molecular, líquido sinovial, caballo.