Concentrations of keratan sulfate in plasma and synovial fluid from clinically normal horses and horses with joint disease.

This research explored the differences in keratan sulfate concentrations in plasma and synovial fluid between healthy horses and those suffering from joint disease. Findings reveal that such concentrations vary and are also influenced by the breed, gender, and specific type of joint ailment.

Study Aim and Design

• The objective of the research was to examine if keratan sulfate concentrations in plasma or synovial fluid were distinctive in normal horses as compared to those with joint disease.
• The study also intended to ascertain if these concentrations differed based on the kind of joint disorder.
• The methodology used was a case-control study involving 67 clinically normal horses, 10 clinically normal foals, and 160 horses with joint disease.
• Keratan sulfate concentrations were measured using an ELISA (Enzyme-Linked Immunosorbent Assay).

Findings

• The results showed that the blood concentration of keratan sulfate in foals peaked at 10 weeks of age, averaging 580 +/- 124 ng/ml.
• In clinically normal horses, the mean plasma keratan sulfate concentration was found to be 200 ng/ml.
• Horses with osteochondral (chip) fractures, other closed intraarticular fractures, inflammatory arthritis (synovitis), infectious arthritis, or osteochondrosis had significantly higher plasma keratan sulfate concentrations than the healthy horses, while horses with osteoarthritis did not.

Variations in Keratan Sulfate Concentration

• Breed, gender, and types of joint disorder were found to influence the concentration of keratan sulfate found in the synovial fluid.
• Standard-bred horses with chip fractures of the metacarpophalangeal/metatarsophalangeal joints had significantly higher keratan sulfate concentrations in the synovial fluid compared to Thoroughbreds.
• Keratan sulfate concentrations in synovial fluid from osteoarthritic carpal joints were lower than in normal carpal joints and tarsocrural joints with inflammatory joint disease.

Conclusion and Implication

• The study shows that while keratan sulfate concentration by itself isn’t a specific marker of joint disease, it can be influenced by different joint disorders.
• This indicates that testing for keratan sulfate concentrations can be a significant part of the diagnostic process for various joint disorders in horses.