The differentiating ability of four plasma biomarkers in canine hip dysplasia

The accumulation of cartilage breakdown products in body fluids has been extensively investigated to assess the accuracy of molecular biomarkers from a diagnostic, prognostic, and therapeutic perspective. Nevertheless, to the authors' knowledge, there is a lack of information about spontaneous models of hip osteoarthritis and the differentiating ability of collagen, noncollagen, and inflammatory biomarkers.

We aimed to assess the accuracy of four plasma biomarkers that could differentiate between healthy dogs and dogs with hip dysplasia.

Twenty-four dogs were used in this institutionally approved study (12 in the mild to severe hip dysplasia group; 12 in the control group). Plasma concentrations of biomarkers were compared. The ability of each marker to differentiate control from diseased dogs was assessed using an independent t-test, logistic regression, and receiving operating characteristics (ROC) analysis.

Three biomarkers were significantly different between the two groups. The collagen marker procollagen type II propeptide (PIICP) was useful in differentiating between control and diseased dogs with the best combination of sensitivity and specificity. The four biomarkers showed high area under the curve (AUC) values.

The results indicate that plasma biomarkers can be used as a screening tool for canine hip dysplasia. Although the cutoff values and diagnostic ability of the biomarkers used in this study show promising results, the sources of individual variability should be addressed. Future studies with larger groups of dogs are needed to correlate plasma levels in serum and synovial fluid during clinical disease.