Viability and cell death of synovial fluid neutrophils as diagnostic biomarkers in equine infectious joint disease: a pilot study.

This research suggests that evaluating the viability and cell-death characteristics of neutrophils (a type of white blood cell) found in synovial fluid (joint lubricant) in horses could be a useful diagnostic tool in distinguishing between joint infections and non-infectious joint inflammation.

Study Design

• The study used samples of synovial fluid, the lubricating liquid in joints, collected from different categories of horse joints: those confirmed as infected, those with severe non-infectious inflammation, and healthy joints. The non-infected joints functioned as controls.
• The researchers isolated, counted, and identified neutrophils in the samples. Neutrophils are a type of white blood cell often involved in the body’s initial response to infection; they defend against invading bacteria and fungi.

Findings

• By using a testing process called flow cytometry, scientists determined viability (the percentage of live cells) and the proportions of apoptotic (programmed cell death) and necrotic (uncontrolled cell death) neutrophils.
• The scientists found that viability was significantly higher in samples from infected joints when compared with the controls — meaning that a greater percentage of neutrophils in the infected samples were alive.
• Regarding cell death, differences were also identified. Apoptosis, or programmed cell death, was more prevalent in the infected joints. On the other hand, necrosis, which is uncontrolled cell death often resulting from external factors like disease or injury, was more commonly found in the non-infectious inflamed and healthy joints.

Implications

• The results suggest that these cell viability and death measurements could potentially be used to distinguish between infectious and non-infectious joint conditions in horses.
• This is a pilot study, therefore the findings are preliminary and more research is required to confirm and extend them.
• If validated further, these findings could represent a valuable diagnostic tool in equine medicine, potentially helping to guide more effective treatments for horses affected by different types of joint conditions.