Methods for measuring platelet reactivity of patients that have received drug eluting stents

Abstract

A method is providing for measuring platelet reactivity of a PCI patient that has a (DES). A blood sample is obtained from the patient. The blood sample is mixed in combination 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; 4) one or more agents to enhance a signal transduction pathway and 5) a receptor activator. The combination is incubated under conditions for agglutinating particles. Platelet-mediated agglutination is assessed in the mixture. The absence of agglutination indicates that the patient has reduced ability to form platelet thrombi.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a continuation-in-part of U.S. Ser. No. 10 / 886,155 filed Jul. 6, 2004, which claims the benefit of U.S. Ser. No. 60 / 485,703, filed Jul. 7, 2003. All of the above applications are fully incorporated herein by reference.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention relates to the field of diagnostic assays, and in particular to methods for measuring platelet reactivity of patients that have received drug-eluting stents (DES). [0004] 2. Description of the Related Art [0005] The role of platelets in mammalian physiology is extraordinarily diverse, but their primary role is in promoting hemostasis. In many situations, an evaluation of the ability of blood to clot is desired, a parameter that is frequently controlled by the ability of platelets to adhere and / or aggregate. Of interest, therefore, is the assessment of the adhesive functions of platelets. For example, questions of interest ...

AI Technical Summary

Benefits of technology

[0022] These and other objects of the present invention are achieved in a method of measuring platelet reactivity of a PCI patient that has a (DES). A blood sample is obtained from the patient. The blood sample is mixed in combination 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; 4) one or more agents to enhance a signal transduction pathway and 5) a receptor activator. The combination is incubated under conditions for agglutinating particles. Platelet-mediated agglutination is assessed in the mixture. The absence of agglutination indicates that the patient has reduced ability to form platelet thrombi.

Problems solved by technology

Current assays to measure platelet aggregation are expensive, time-consuming, cumbersome, and generally not suitable for a clinical environment.

However, since ADP activates at least two different receptors (P2Y1 and P2Y12 and perhaps P2X1), it has the potential for lower specificity and background noise.

However collagen is highly variable due its quaternary structure, which dramatically affects it ability to activate platelets and due to the fact it is derived from biological tissue and sensitive to minor changes in temperature and pH.

Neither collagen nor ADP provide specificity to the P2Y12 receptor and therefore by themselves are not the optimal choice for the determination of the effects of P2Y12 inhibitors.

From a clinical perspective, the routine measurement of platelet reactivity at the time of PCI is generally impractical because of the need to use specialized laboratory techniques such as light transmittance aggregometry (LTA).

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