Prothrombin concentrate

A G (guanine) to A (adenine) transition in position 20210 of the prothrombin gene (prothrombin 20210 A allele) has been described that leads to increased prothrombin concentrations and, in turn, increased risk for venous thrombosis (88). This G-to-A transition that occurs in the 3 untranslated region of the gene may not be the only reason for increased prothrombin concentrations because apparently only 25% of individuals with prothrombin concentrations greater than 115% carry the prothrombin 20210 A allele (88). 

The most important adverse effect is bleeding. With coumarins, this can be counteracted by giving vitamin Ki. Coagulability of blood returns to normal only after hours or days, when the liver has resumed synthesis and restored sufficient blood levels of clotting factors. In urgent cases, deficient factors must be replenished directly (e.g., by transfusion of whole blood or of prothrombin concentrate). 

Paradoxically, giving excessive doses of vitamin K or its analogs in an attempt to correct hypoprothrombinemia associated with severe hepatitis or cirrhosis may actually result in further depression of the prothrombin concentration. 

The increase in capacitance with prothrombin concentration is presented in Figure 5. Even in the absence of Ca++ there is an appreciable increase in capacitance upon addition of prothrombin. However, the initial increase of capacitance with prothrombin concentration is less steep in the absence or at very low concentrations of calcium 10"3mM) than at the higher concentrations. In the low Ca++ concentration region the capacitance increases almost linearly with prothrombin up to concentrations of about 5 /ig/mL. In this concentration region the surface concentrations as seen from Figure 2 are also a linear function of the bulk concentration of prothrombin. Every adsorbed prothrombin molecule up to a given surface concentration contributes by the same value to the surface-layer capacitance Ca... 

In Figure 6 the dependence of capacitance on calcium concentration for different concentrations of prothrombin is shown. Curves a and b were reconstructed from the curves obtained by changing the concentration of prothrombin at different constant concentrations of Ca+. Curve c was obtained by changing the concentration of Ca++ at a prothrombin concentration of 2.4 jug/mL. We obtain a very good agreement by the two different ways at the prothrombin concentration of 2.4 /ig/mL. It is evident from the increase in the capacitance that substantial penetration of the lipid layer by the prothrombin is observed even in the absence of Ca++. A further pronounced increase in penetration is observed ca. O.lmM Ca++. 

Vitamin E therapy in vitamin K-deficient subjects and subjects taking anticoagulants reduces active plasma prothrombin concentrations (44). 

In severe hepatocellular disease the prothrombin concentration can be further depressed by high doses of vitamin K (6,7). 

Thrombin, Topical. Thromboforr Topostasin A prepn of thrombin isolated from the prothrombin concentrate of bovine plasma, see W. H. Saegers, Prothrombin (Harvard Univ. Press, 1962) p 582. Prepn Seegers, Arch. Biochem. 3, 363 (1943-44) U.S. pat. 2,433,299 (1947 to Parke, Davis). 

The penetration of prothrombin into a monolayer containing 25% PS- 75% PC, starts only at higher prothrombin concentrations than on the pure PS monolayer, and a cooperative dependence of the capacitance and of the pseudocapacitance peaks on the prothrombin concentration is observed. However, the limiting capacitances reached at higher prothrombin concentrations are about the same with both mono-layers it is 7 yF.cm 2. These high capacitances are obtained instantaneously upon nondamaging contact of the monolayer by the electrode. 

Saitoh, S., Dteda, K., Koida, L, Tsubota, A., Arase, Y., Chayama, K. and Kumada, H., 1994, Serum des-gamma-carboxy prothrombin concentration determination by avidin-biotin complex in small hepatocellular carcinomas. Cancer, 74 2918 - 2923. 

After taking mefenamic acid 500 mg four times daily for a week the mean prothrombin concentrations of 12 healthy subjects stabilised on warfarin fell by about 3.5%. Microscopic haematuria was seen in 3 of them, but no overt haemorrhage. Their prothrombin concentrations were 15 to 25% of normal, well within the accepted anticoagulant range. ... 

Page RC, de Beer EJ, Orr ML. Prothrombin studies using Russell viper venom, n. Relation of clotting time to prothrombin concentration in human plasma. JLab ClinMed ( 9AV) 27,197-201. 

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