Incidence of transfusion reactions and retention of procoagulant and anticoagulant factor activities in equine plasma.
Authors: Wilson E M, Holcombe S J, Lamar A, Hauptman J G, Brooks M B
Journal: Journal of veterinary internal medicine
Summary
# Editorial Summary Frozen equine plasma prepared through gravity sedimentation and stored at −20°C retains most clotting factor activity within normal ranges, though certain factors undergo measurable reduction during processing and storage. Wilson and colleagues examined factor activities (VII–XII, antithrombin, and Protein C) at three timepoints—baseline, after 48-hour refrigerated sedimentation, and after 90 days of freezing—whilst simultaneously reviewing transfusion reactions in 50 hospitalised horses receiving such plasma. Factors IX, X, XI, antithrombin and Protein C showed statistically significant losses, with factor IX declining 43%, factor XI 48%, and Protein C 26%; notably, only factor X fell below the reference range, whilst all others remained clinically adequate. Transfusion reactions occurred in 5 of 50 recipient horses (10%), indicating a relatively low adverse event rate despite the biochemical changes during preparation. For practitioners administering non-commercial frozen plasma, these findings suggest the product remains therapeutically viable for most coagulopathies, though clinicians should consider the reduced factor X activity when managing cases with specific deficits in this factor, and remain alert to the 10% reaction incidence when monitoring transfused horses.
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Practical Takeaways
- •Frozen equine plasma prepared in-house retains sufficient clotting factor activity for transfusion, making it a viable option for hospitalized horses requiring hemostatic support despite modest factor losses during processing
- •The 10% transfusion reaction rate is acceptably low, allowing frozen plasma to be used with reasonable safety in clinical settings
- •Factor X activity may fall below reference range; consider supplementation or commercial plasma if factor X deficiency is a specific clinical concern
Key Findings
- •Frozen equine plasma retained clotting factor activities within reference ranges except factor X (33% reduction), with factors IX, X, XI showing 43-48% reductions during processing
- •Antithrombin and Protein C showed 10% and 26% reductions respectively but remained clinically acceptable after freezing
- •Transfusion reactions occurred in 5/50 horses (10%) receiving frozen plasma, indicating relatively low incidence of adverse effects
- •Plasma preparation by gravity sedimentation followed by freezing at -20°C for 90 days preserved most coagulation factors adequately for clinical use