Coagulation Factor Inhibitor Plasmas (FIPs) are produced from normal human plasmas from which specific factors have been removed by selective affinity immuno-adsorption and an antibody inhibitory to the specific factor is added to provide neutralizing activity. These products can be used as a substitute for plasmas from patients that have developed neutralizing antibodies to coagulation factors. All of these products are intended for research use only.
Source:Normal citrated human plasma depleted of Factor VII using antibodies directed to FVII immobilized on agarose beads. Polyclonal antibody inhibitory to FVII was added to provide FVII neutralizing activity.
Activity:FIPs are produced to one or more inhibitor activity categories:
Mild:1-10 BU/ml
Moderate:≥ 10-50 BU/ml
Strong:≥ 50-200 BU/mlThe inhibitor potency is measured by standard Bethesda activity assay.
Bethesda assay performed at a 1:20 dilution, then mixed with an equal volume of normal plasma and incubated at 37ºC for 120 minutes. The FVII activity was measured by one stage clotting assay and the resiual FVII activity was calculated as a percentage activity compared to a buffer control run in parallel. The residual FVII activity is converted to Bethesda units using the Bethesda chart or graph. The Bethesda value derived (BU/ml) is multiplied by the initial dilution of the sample to obtain the corrected inhibitor concentration.
Storage and Stability:Aliquot to avoid repeated freezing and thawing and store at -70°C. Aliquots are stable for at least 6 months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
