Scientists Examine New Joint Disease Evaluation Method

Danish researchers have been investigating a novel technique for evaluating joint disease. This involves the serial evaluation of cartilage-derived retinoic acid protein (CD-RAP) levels in individual horses as a measure of cartilage synthesis and/or regeneration.

Sensitive and specific tests are urgently needed in both human and veterinary medicine to detect early changes in joint cartilage. One way researchers are doing this is by identifying specific "markers" found in synovial fluid, serum (blood), and urine. 

CD-RAP is the latest molecule to be studied as a potential "marker" for joint disease in horses, according to a study out of the University of Copenhagen.

In this inaugural study of CD-RAP in horses, the researchers used a commercial test kit to detect the potential marker in all of the horses in the study, but they noted large intra- and inter-assay variations in CD-RAP concentrations (14.0 to 45.5%).

In contrast, CD-RAP concentrations were significantly lower in 12 horses that had been injected with lipopolysaccharide (LPS) to induce arthritis, compared to the levels measured in the control group. CD-RAP levels remained for the remaining 144 hours of the study.

These results suggest that CD-RAP might prove to be a useful marker for monitoring arthritis or joint injury/disease in individual horses to track disease progression, but further research is needed.  

The study, "Cartilage-derived retinoic acid-sensitive protein in equine synovial fluid from healthy and diseased joints," will be published in an upcoming edition of the Equine Veterinary Journal. The abstract is currently available on PubMed. 

About the Author

Stacey Oke, DVM, MSc

Stacey Oke, MSc, DVM, is a practicing veterinarian and freelance medical writer and editor. She is interested in both large and small animals, as well as complementary and alternative medicine. Since 2005, she's worked as a research consultant for nutritional supplement companies, assisted physicians and veterinarians in publishing research articles and textbooks, and written for a number of educational magazines and websites.

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