Rabbit Human Factor VII Antibody

Precipitating polyclonal rabbit antiserum to human coagulation Factor VII. Plasma Factor VII is a vitamin K-dependent glycoprotein (MW 63,000) with an electrophoresis mobility in the beta region. It circulates in plasma in a semi-active form, even in the absence of tissue factor. Then procoagulant activity of FVII can be destroyed by heating to 56C. It is unstable below pH 3 and above pH 9. It survives he clotting process and its presence can be demonstrated in serum. After isolation its molecular weight was 44,700. Factor VII is a serine protease depending on a lipid cofactor and can be activated to FVIIa by factors IXa, Xa and XIIIa, thereby linking the intrinsic and extrinsic coagulation systems since FXII and FIX can be activated by kallikrein. The normal adult plasma FVII level is about 0.5 to 1.0 mg/ml. In normal newborn infants the average level is about 50% of the adult concentration. A deficiency of FVII, congenital or acquired, results in a bleeding disorder. The congenital form is rare but the acquired form is commonly seen in association with a deficiency of FII, FIX and FX in liver disease and in patients taking coumarin-type anticoagulant drugs. Both procoagulant activity and FVII-related antigen are depressed. In haemorrhagic disease of the newborn, procoagulant activity is reduced but not the level of the FVII antigen. A similar discrepancy may be seen in congenital deficiencies but in other types FVII antigen will be severely reduced as a result of genetic suppression of synthesis capacity. If still present, the FVII molecules appear to be biologically defective. Heterozygote carriers can now be detected. FVII procoagulant activity and related antigen levels have been shown to correlate directly with the plasma triglyceride concentration. This makes FVII a risk factor for myocardial infarction; immediately following an acute myocardial infarction patients have increased plasma FVII procoagulant activity. FVII is purified from plasma and Freund's complete adjuvant is used in the first step of the immunization procedure.