The Impact of Systemic Treatment With Flunixin Meglumine on the Two Antiproteases Alpha‐2‐Macroglobulin ( A2M ) and Alpha‐1‐Antitrypsin ( A1AT ) in Equine Plasma and Platelet‐Rich Fibrin ( PRF )

PURPOSE: To evaluate the effect of flunixin meglumine, a systemic non-steroidal anti-inflammatory drug (NSAID), on the antiproteases, A2M and A1AT, in equine plasma and PRF. METHODS: A prospective cross-sectional study. Plasma, solid PRF, and liquid PRF were collected from a control-group that included healthy horses not treated with NSAIDs within the last 3 months. The NSAID-group were ophthalmology patients with no systemic inflammatory disease, and all received a full dose of flunixin meglumine (1.1 mg/kg BID PO or IV) for three or more days prior to collection. Samples were collected and prepared using a standardized protocol for plasma and PRF preparation. Concentrations of A2M and A1AT were analyzed with ELISA kits. Statistical analysis with Mann-Whitney U tests and Wilcoxon signed-rank tests was performed using significance set at p < 0.05. RESULTS: No significant differences were found between the control-group (n = 12) and NSAID-group (n = 12) for any of the blood products (p > 0.05). Plasma had a significantly higher amount of A2M compared to solid and liquid PRF (both p < 0.001). Solid PRF had the highest concentration of A1AT and was significantly higher when compared to liquid PRF (p < 0.001), but not when compared to plasma (p = 0.071). CONCLUSIONS: The systemic NSAID, flunixin meglumine, does not appear to significantly alter antiprotease concentrations in equine plasma or PRF. Although PRF should not be used as a replacement for plasma, solid PRF may be a good adjunctive therapy for the treatment of keratomalacia due to its high A1AT concentration.