Platelet blockade assay
AssigneeMount Sinai School of Medicine
InventorBarry S. Coller
Life of this patent
Estimating the term…
Abstract
The present invention is an assay for determining glycoprotein IIb/IIIa receptor blockade in whole blood. Agglutinization of small polymeric beads coated with a glycoprotein IIb/IIIa ligand such as fibrinogen results when the beads are contacted with whole blood containing platelets with glycoprotein IIb/IIIa receptors that are not blocked. Failure to agglutinate indicates that blockade of the GPIIb/IIIa receptors has been achieved. In a preferred embodiment, the addition of a thrombin receptor activator results in an assay that is rapid and convenient enough to be performed at the bedside and that results in agglutination of the small polymeric beads within a convenient, known period of time if the glycoprotein IIb/IIIa receptors are not blocked.
Claims35
A method of determining whether an individual has reduced ability to form platelet thrombi, comprising the steps of:
- a) obtaining a blood sample from the individual being assessed;
- b) mixing the blood sample with 1) an anticoagulant;
- 2) sufficient buffer to maintain the pH and salt concentration of the anticoagulated blood within a range suitable for platelet aggregation;
- 3) a platelet GPIIb/IIIa receptor ligand immobilized on a solid surface and 4) a platelet aggregation activator;
- c) agitating the mixture formed in b) for a period of time sufficient for unblocked platelet GPIIb/IIIa receptors to bind with the platelet GPIIb/IIIa receptor ligands on said solid surface;
- and
- d) assessing platelet-mediated agglutination in the agitated mixture, wherein the absence of agglutination indicates that the individual has reduced ability to form platelet thrombi.
A method of determining the degree of GPIIb/IIIa receptor blockade in a blood sample, comprising the steps of:
- a) obtaining a blood sample from an individual being assessed;
- b) mixing the blood sample with 1) an anticoagulant;
- 2) sufficient buffer to maintain the pH and salt concentration of the anticoagulated blood within a range suitable for platelet aggregation;
- 3) a platelet GPIIb/IIIa receptor ligand immobilized on a solid surface and 4) a platelet aggregation activator;
- c) agitating the mixture formed in b) for a period of time sufficient for unblocked platelet GPIIb/IIIa receptors to bind with the platelet GPIIb/IIIa receptor ligands on said solid surface;
- and
- d) assessing platelet-mediated agglutination in the agitated mixture, wherein the absence of agglutination indicates that about 80% or more of the GPIIb/IIIa receptors are blocked, and the presence of normal agglutination indicates that less than about 50% of the GPIIb/IIIa receptors are blocked.
A method of diagnosing Glanzmann thrombasthenia, other platelet function defects, or thrombocytopenia in an individual, comprising the steps of:
- a) obtaining a blood sample from an individual being assessed for Glanzmann thrombasthenia, other platelet function defects, or thrombocytopenia at a time when the individual has not been administered an agent that blocks platelet GPIIb/IIIa receptors;
- b) mixing the blood sample with 1) an anticoagulant;
- 2) sufficient buffer to maintain the pH and salt concentration of the anticoagulated blood within a range suitable for platelet aggregation;
- and 3) a platelet GPIIb/IIIa receptor ligand immobilized on a solid surface;
- c) agitating the mixture formed in b) for a period of time sufficient for unblocked platelet GPIIb/IIIa receptors to bind with the platelet GPIIb/IIIa receptor ligands on said solid surface;
- and
- d) assessing platelet-mediated agglutination in the agitated mixture, wherein the absence of agglutination is indicative of Glanzmann thrombasthenia, other platelet function defects, or thrombocytopenia.
Dependencies are inferred from the claim text.