Chromogenic assays for equine coagulation factors VII, VIII:C, IX, and X, and C1-esterase inhibitor.
OBJECTIVE
To adapt manual human chromogenic assays for coagulation factors VII (F.VII), VIII:coagulant (F.VIII:C), IX (F.IX), and X (F.X), and C1-esterase inhibitor (C1-INH) for use with an automated analyzer, and to measure the activity of these proteins in horses.


METHODS
10 healthy horses were used to determine ranges for the assays. Pooled plasma for standards was collected from an additional 20 healthy horses.


METHODS
A computer-assisted analyzer was programmed from the manual method for commercially available human F.VII, F.VIII:C, F.IX, F.X, and C1-INH chromogenic assay kits. Standards were prepared from pooled citrated equine plasma for the F.VII, F.VIII:C, and F.X assays, and from commercial pooled citrated human plasma for F.IX and C1-INH assays.


RESULTS
Mean +/- SD activities in citrated equine plasma from 10 horses were 226 +/- 19% for F.VII; 209 +/- 31% for F.VIII:C; 149 +/- 38% for F.IX; 88 +/- 12% for F.X; and 18.4 +/- 8.4% for C1-INH. Intra-assay coefficients of variation (CV) were 5.3% for F.VII; 2.1% for F.VIII:C; and 3.0% for C1-INH. Interassay CV were 5.7% for F.VII; 7.4% for F.VIII:C; 3.8% for F.IX; 14.4% for F.X; and 22.0% for C1-INH.


CONCLUSIONS
Human chromogenic assay kits can be automated and used to measure F.VII, F.VIII:C, F.IX, F.X, and C1-INH activities in citrated equine plasma.


CONCLUSIONS
Human chromogenic assays can be routinely used to measure F.VII, F.VIII:C, F.IX, F.X, and C1-INH in horses, and may be useful in evaluation of horses with disorders of hemostasis.
Topper
M J
MJ
Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens 30602, USA.
Prasse
K W
KW
D000818:Animals; D001322:Autoanalysis / Q000379:methods / Q000662:veterinary*; D001779:Blood Coagulation Factors / Q000032:analysis*; D002863:Chromogenic Compounds; D003174:Complement C1 Inactivator Proteins / Q000032:analysis; D005164:Factor IX / Q000032:analysis; D005167:Factor VII / Q000032:analysis; D005169:Factor VIII / Q000032:analysis; D005170:Factor X / Q000032:analysis; D006736:Horses / Q000097:blood*; D006801:Humans; D012016:Reference Values; D015203:Reproducibility of Results
D001779:Blood Coagulation Factors; D002863:Chromogenic Compounds; D003174:Complement C1 Inactivator Proteins; D005167:Factor VII; D005169:Factor VIII; D005164:Factor IX; D005170:Factor X