Heparin Neutralization during Collection and Processing of Blood Inhibited by Pyridoxal 5′-Phosphate

Putten, Janjaap van; Ruit, Marjo van de; Beunis, Marlene; Hemker, H.C.

doi:10.1159/000215066

Cited by 6 publications

(6 citation statements)

References 12 publications

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“…This represents a heparin concentration that in rigor ously platelet and PF 4 free plasma will cause more then 95% inhibition of thrombin formation (15). It has been shown that mere venipuncture, if carried out under routine conditions, induces platelets to produce a quantity of heparin neutralizing material equivalent to 0.183 ± 0.067 U/ml of heparin (22). The amount of heparin neutralized in our experiments, in which platelets were maximally triggered with Ca-ionophore, therefore does not seem to be unrealistically high.…”

Section: Discussionmentioning

confidence: 48%

“…We postulate that this retardation is instrumental in obtaining an antithrombo tic effect with low doses of heparin. On basis of the data of van Putten et al (22) we can assume that a circulating heparin concentration of 0.1-0.2 U/ml will hardly be detected by routine laboratory methods. This accounts for the difficulty in finding a laboratory correlate to the antithrombotic action of low dose heparin.…”

Section: Discussionmentioning

confidence: 99%

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The Effect of Trace Amounts of Tissue Factor on Thrombin Generation in Platelet Rich Plasma, its Inhibition by Heparin

1989

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SummaryAmounts of human brain thromboplastin that do not stimulate thrombin generation in platelet poor plasma, were shown to advance by about 4 min an explosive formation of thrombin that occurs after recalcification in the presence of blood platelets. This synergistic effect is inhibited by the specific thrombin inhibitor hirudin and mimicked by adding low concentrations (< 5 nM) of thrombin to platelet rich plasma. It is our conclusion that, small amounts of thrombin, generated under the influence of thromboplastin induced procoagulant activity in the blood platelets. This activity is most likely mainly due to procoagulant phospholipids. Heparin inhibits this effect and retards the explosive thrombin formation. It does not, however, diminish the peak amount of thrombin eventually formed, because heparin neutralizing material released from the activated platelets quenches the heparin effect.

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Section: Discussionmentioning

confidence: 48%

Section: Discussionmentioning

confidence: 99%

The Effect of Trace Amounts of Tissue Factor on Thrombin Generation in Platelet Rich Plasma, its Inhibition by Heparin

1989

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“…Heparin binds to numerous plasma substances (4,(12)(13)(14)(15). Utilizing various techniques, others have demonstrated consider able quantities of masked heparin (3,5,15). The technique described here is simple, can be applied to blood samples collected with any anticoagulation technique, and will unmask any exogenous heparin added to plasma.…”

Section: Discussionmentioning

confidence: 99%

Modification of an Amidolytic Heparin Assay to Express Protein-Bound Heparin and to Correct for the Effect of Antithrombin III Concentration

1987

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SummaryA modification of an anti-Xa assay for plasma heparin has been devised using a low molecular weight dextran sulfate that competitively binds protein heparin neutralizers and displaces masked heparin. The addition of 0.12 mg dextran sulfate per ml of plasma permits heparin, neutralized by the products of platelet aggregation, to recover full functional activity against Xa. The assay will permit a more accurate assessment of both exogenous plasma heparin and endogenous liepaiin-like activity in blood samples collected with varying techniques. A further modification is proposed employing polybrene to neutralize the plasma heparin-like material providing a concurrent control for each sample that increases accuracy by eliminating the effect of varying AT-III levels which have anti-Xa activity.

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“…The APTTs of plasmas obtained at 600 x g were slightly shorter than those obtained at 940 x g and 2200x g. This difference might be due to a higher platelet concentration in the Storage conditions had considerable influence on the APTT, Both shortening and lengthening of APTT was observed. Shortening of APTT may be due to in vitro release of heparin neutralizing activity from platelets, as has been suggested by several other authors (7,10,11). Lengthening may be due to inactivation of labile clotting factors like Factor V and Factor VIII.…”

Section: Aptts Of Healthy Persons Obtained In Our Laboratory (Thble 1)mentioning

confidence: 59%

Monitoring Heparin Therapy by the Activated Partial Thromboplastin Time - The Effect of Pre-Analytical Conditions

Besselaar¹,

Meeuwisse-Braun²,

Jansen-Grüter³

et al. 1987

Thromb Haemost

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SummaryBlood and plasma specimens from patients receiving heparin were collected and stored under various conditions. The effect of these conditions on the activated partial thromboplastin time (APTT) was assessed. Four APTT reagents were used. Blood samples centrifuged at 600 × g gave slightly shorter APTTs than samples centrifuged at 940 × g and 2200 × g. Storage of uncentrifuged citrated-blood at room temperature resulted in 15-29% shortening of the APTT, depending on the reagent used. Storage of the same blood samples at 4° C resulted in 6-19% lengthening of the APTT. The presence of HEPES-buffer in citrated-blood shortened the APTT of heparinized patient specimens, but not of normal specimens. When blood was collected in a mixture of citric acid, theophylline, adenosine and dipyridamole (CTAD-mix-ture), storage at room temperature induced 0-11% decrease of the APTT, depending on the reagent used. Storage of CTAD-blood at 4° C resulted in 7-19% lengthening of the APTT. Shortening of the APTT could be explained by release of platelet factor 4 (PF4). Release of PF4 could be inhibited by CTAD-mixture. These data suggest that storage of CTAD-blood at room temperature is the best pre-analytical condition for reliable monitoring of heparin therapy by the APTT.

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Heparin Neutralization during Collection and Processing of Blood Inhibited by Pyridoxal 5′-Phosphate

Cited by 6 publications

References 12 publications

The Effect of Trace Amounts of Tissue Factor on Thrombin Generation in Platelet Rich Plasma, its Inhibition by Heparin

The Effect of Trace Amounts of Tissue Factor on Thrombin Generation in Platelet Rich Plasma, its Inhibition by Heparin

Modification of an Amidolytic Heparin Assay to Express Protein-Bound Heparin and to Correct for the Effect of Antithrombin III Concentration

Monitoring Heparin Therapy by the Activated Partial Thromboplastin Time - The Effect of Pre-Analytical Conditions

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