ANALYSIS OF COAGULATION PROTEINS AS ACUTE-PHASE REACTANTS IN HORSES WITH COLIC

Objectives-To measure coagulation factor VIII:coagulant (F.VIII:C) and C1-esterase inhibitor (C1-INH), hemostasis-associated acute-phase rea ctant proteins, and coagulation factors VII (F.VII), IX (F.IX), and X (F.X), hemostasis proteins not associated with an acute-phase response , in a select population of horses with colic and hemostasis abnormali ties, and presumed to have acute-phase changes. To compare these value s and other routine hemostasis test results in the horses with colic w ith values for a population of healthy horses. To correlate the values of known equine acute-phase reactants, F.VIII:C and fibrinogen, to th ose of other tests of hemostasis. To identify hemostasis-associated ac ute-phase reactant proteins and gain insights into the effects the acu te-phase response has on hemostatic abnormalities in horses with colic syndrome. Sample Population-54 plasma samples from horses with colic attributable to inflammatory (n = 39) or strangulating (n = 15) intest inal disorders. Procedure-Plasma samples were evaluated for activities of F.VII, F.VIII:C, F.IX, F.X, C1-INH, antithrombin ill, protein C, p lasminogen, and alpha(2)-antiplasmin (alpha(2)AP); fibrinogen concentr ation; and prothrombin (PT) and activated partial thromboplastin (APTT ) times. Results-Horses with colic had significantly higher fibrinogen concentration, greater alpha(2)AP and protein C activities, and longe r PT and APTT than did healthy horses. Horses with colic also had sign ificantly lower mean F.VII activity than did healthy horses. Significa nt positive correlations between fibrinogen concentration and F.VIII:C , C1-INH, and alpha(2)AP values, and between F.VIII:C activity and fib rinogen, C1-INH, alpha(2)AP, and plasminogen values were identified. C onclusions-An acute-phase response contributes to changes observed in coagulation proteins in horses with colic attributable to inflammatory and strangulating intestinal disorders. The data suggest that plasmin ogen, alpha(2)AP, and C1-INH should be considered equine acute-phase p roteins.