Deficient Human Plasma Research Articles

Preparation of Factor IX Deficient Human Plasma by Immunoaffinity Chromatography Using a Monoclonal Antibody

AbstractA murine hybridoma clone is described that grows continuously in culture and produces a monoclonal antibody we have called Royal Free Monoclonal Antibody to factor IX No. 1 (RFF-IX/1). This has high affinity for a coagulation site on factor IX. RFF-IX/1 immobilised on sepharose can be used to deplete factor IX from normal human plasma. This immunoaffinity depleted plasma is indistinguishable from severe Christmas disease plasma and can be used as the substrate in a one stage coagulation assay for factor IX. The affinity column has high capacity and can be regenerated so that large scale production from normal plasma of factor IX deficient plasma as a diagnostic reagent is now feasible.

Preparation of factor IX deficient human plasma by immunoaffinity chromatography using a monoclonal antibody

A murine hybridoma clone is described that grows continuously in culture and produces a monoclonal antibody we have called Royal Free Monoclonal Antibody to factor IX No. 1 (RFF-IX/1). This has high affinity for a coagulation site on factor IX. RFF-IX/1 immobilised on sepharose can be used to deplete factor IX from normal human plasma. This immunoaffinity depleted plasma is indistinguishable from severe Christmas disease plasma and can be used as the substrate in a one stage coagulation assay for factor IX. The affinity column has high capacity and can be regenerated so that large scale production from normal plasma of factor IX deficient plasma as a diagnostic reagent is now feasible.

Alternative pathways of thromboplastin-dependent activation of human factor X in plasma.

To determine the interrelationships of the major coagulation pathways, the activation of 3H-labeled factor X in normal and various deficient human plasmas was evaluated when clotting was triggered by dilute rabbit or human thromboplastin. Various dilutions of thromboplastin and calcium were added to plasma samples containing 3H-factor X, and the time course of factor X activation was determined. At a 1/250 dilution of rabbit brain thromboplastin, the rate of factor X activation in plasmas deficient in factor VIII or factor IX was 10% of the activation rate of normal plasma or of factor XI deficient plasma. Reconstitution of the deficient plasmas with factors VIII or IX, respectively, reconstituted normal factor X activation. Similar results were obtained when various dilutions of human thromboplastin replaced the rabbit thromboplastin. From these plasma experiments, it is inferred that the dilute thromboplastin-dependent activation of factor X requires factors VII, IX, and VIII. An alternative extrinsic pathway that involves factors IX and VIII may be the physiologic extrinsic pathway and hence help to explain the consistent clinical observations of bleeding diatheses in patients deficient in factors IX or VIII.

In vitro effects of aspirin in fibrinolysis.

In <i>in vitro</i> studies, aspirin inhibited the lytic activity of streptokinase (SK), urokinase (UK), plasmin, and of euglobulins prepared from normal and Hageman deficient human plasmas. Aspirin also inhibited the generation of activator activity in the plasminoplastin generation test assay. This anti-fibrinolytic effect of aspirin was not due to its acid pH. Chicken plasma being deficient in Hageman factor and in proactivator exerted also a very potent anti-SK and anti-UK effect.

Factor VII deficiency in beagle dog plasma and its use in the assay of human factor VII.

DURING routine screening tests on a group of beagle dogs before a toxicological test, it was noted that several dogs showed a prolonging of the one-stage prothrombin time. Some of these dogs were found to be related (Fig. 1). The results of more detailed tests showed that intrinsic prothrombin activation was normal (Table 1) and that extrinsic prothrombin activation could be corrected by adding aliquots of normal human plasma or serum, normal dog plasma or serum, and Russell viper venom (Table 2). In addition, liver function tests were normal and the presence of an inhibitor was excluded (Table 3). Finally, factor VII activity assays, using congenitally deficient human plasma, confirmed that this factor specifically was reduced.