Detection of activated platelets and platelet-leukocyte aggregates in horses.

This research investigates the potential use of detection tests for identifying activated platelets and platelet-leukocyte aggregates in horses. The findings show that flow cytometric techniques can effectively detect these parameters and could be potentially useful in diagnosing prothrombotic disorders in horses.

Research Methodology

• The study was conducted using blood samples from three healthy Thoroughbred horses.
• Assessment of spontaneous platelet aggregation, platelet activation, and platelet-leukocyte aggregates was done using microscopic and flow cytometric assays.
• Platelet activation was gauged by evaluating the binding of anti-human fibrinogen to both unactivated and activated platelets. The platelets were activated using ADP, thrombin, thrombin agonist receptor peptide, and platelet activating factor.
• Platelet-leukocyte aggregates were analyzed both microscopically and through flow cytometric determination of leukocyte fluorescence that resulted from the binding of fluorescently labeled platelets to leukocytes.

Results

• Findings indicated that equine platelets spontaneously aggregated when blood was stirred at low, medium, and high speeds.
• When compared to unactivated platelets, the activated platelets displayed a significant increase in the percentage of cells with increased fluorescence intensity and in mean fluorescence intensity.
• Unactivated platelets formed aggregates with neutrophils and monocytes, but not with lymphocytes.
• Activation of platelets led to a calcium-dependent increase in the formation of platelet-leukocyte aggregates.

Conclusions

• The study successfully demonstrated that flow cytometric techniques can be utilized to detect in vitro platelet activation and platelet-leukocyte aggregates in horses.
• The techniques may also prove to be useful in diagnosing prothrombotic disorders in horses, opening up a new field of testing and potential treatments.