Method and device for monitoring asprin response

Abstract

The invention provides a method of monitoring the response of platelets to a COX1 inhibitor such as aspirin. The method involves collecting platelet-containing mammalian blood treated with a COX1 inhibitor; mixing the blood with a COX1-dependent platelet agonist, such as arachidonic acid, monitoring extracellular ATP in the agonist-activated blood to generate a measurement, and comparing the measurement to a standard value. Devices, systems, and kits for carrying out the method are also provided.

1 . A method of monitoring COX1 inhibitor response comprising: 
 collecting platelet-containing mammalian blood treated with a COX1 inhibitor;    mixing the blood with a COX1-dependent platelet agonist to generate agonist-activated blood;    monitoring an extracellular platelet-release-reaction product in the agonist-activated blood to generate a measurement; and    comparing the measurement to a standard value.    
     
     
         2 . The method of  claim 1  wherein the COX1 inhibitor is aspirin.  
     
     
         3 . The method of  claim 1  wherein the extracellular platelet-release-reaction product is ATP.  
     
     
         4 . The method of  claim 1  wherein the COX1-dependent platelet agonist is arachidonic acid.  
     
     
         5 . The method of  claim 1  wherein the COX1-dependent platelet agonist is a phospholipase A 2  activator.  
     
     
         6 . The method of  claim 1  further comprising diluting the blood.  
     
     
         7 . The method of  claim 3  wherein the step of monitoring extracellular ATP comprises: 
 adding to the blood an ATP-consuming enzyme that catalyzes a reaction; and    monitoring the enzyme-catalyzed reaction.    
     
     
         8 . The method of  claim 7  wherein monitoring the enzyme-catalyzed reaction comprises monitoring a product produced by the reaction.  
     
     
         9 . The method of  claim 8  wherein the product is light.  
     
     
         10 . The method of  claim 9  wherein the enzyme is luciferase, the method further comprising adding luciferin to the blood.  
     
     
         11 . The method of  claim 10  wherein the luciferin and luciferase are added to the blood before the blood is mixed with the COX1-dependent platelet agonist.  
     
     
         12 . The method of  claim 10  wherein the luciferin and luciferase are added to the blood after the blood is mixed with the COX1-dependent platelet agonist.  
     
     
         13 . The method of  claim 3  wherein less than 100 μl of blood is collected from the mammal.  
     
     
         14 . The method of  claim 3  wherein less than 10 μl of blood is collected from the mammal.  
     
     
         15 . The method of  claim 3  wherein the platelet-containing blood is whole blood.  
     
     
         16 . The method of  claim 15  wherein less than 100 μl of whole blood is mixed with the COX1-dependent platelet agonist.  
     
     
         17 . The method of  claim 15  wherein less than 10 μl of whole blood is mixed with the COX1-dependent platelet agonist.  
     
     
         18 . The method of  claim 1  wherein the standard value is determined by a method comprising: 
 collecting platelet-containing standard blood from the mammal;    mixing the standard blood with the COX1-dependent platelet agonist to generate agonist-activated standard blood; and    monitoring the extracellular platelet-release-reaction product in the agonist-activated standard blood to generate the standard value;    wherein the standard blood is not treated with the COX1 inhibitor.    
     
     
         19 . The method of  claim 3  further comprising diluting the blood, wherein the step of monitoring extracellular ATP comprises: 
 adding luciferin and luciferase to the blood; and    monitoring light produced by the luciferase.    
     
     
         20 . The method of  claim 19  wherein the standard value is determined by a method comprising: 
 collecting platelet-containing standard blood from the mammal;    diluting the standard blood;    mixing the standard blood with the COX1-dependent platelet agonist to generate agonist-activated standard blood; and    monitoring extracellular ATP in the agonist-activated standard blood to generate the standard value, wherein the step of monitoring extracellular ATP comprises (a) adding luciferin and luciferase to the standard blood, and (b) monitoring light produced by the luciferase;    wherein the standard blood is not treated with the COX1 inhibitor.    
     
     
         21 . The method of  claim 20  wherein the COX1-dependent platelet agonist is arachidonic acid.  
     
     
         22 . The method of  claim 20  wherein the luciferin and luciferase are added to the standard blood before mixing the standard blood with the COX1-dependent platelet agonist.  
     
     
         23 . The method of  claim 20  wherein the luciferin and luciferase are added to the standard blood after mixing the standard blood with the COX1-dependent platelet agonist.  
     
     
         24 . A device for monitoring COX1 inhibitor response comprising: 
 a fluid-tight material forming an assay chamber;    a pump functionally linked to the assay chamber for pumping fluids into the assay chamber;    a light detector functionally linked to the assay chamber for detecting light emitted in the assay chamber;    a fluid-tight material forming a blood chamber for holding blood, the blood chamber functionally linked to the pump;    a fluid-tight material forming an enzyme chamber for holding a solution of a light-producing ATP-consuming enzyme, the enzyme chamber functionally linked to the pump; and    a fluid-tight material forming an agonist chamber for holding a solution of a COX1-dependent platelet agonist, the agonist chamber functionally linked to the pump.    
     
     
         25 . The device of  claim 24  further comprising a valve functionally linked to the pump, the assay chamber, the blood chamber, the enzyme chamber, and the agonist chamber.  
     
     
         26 . The device of  claim 24  further comprising a fluid-tight material forming a dilution medium chamber for holding a solution of a dilution medium, the dilution medium chamber functionally linked to the pump.  
     
     
         27 . The device of  claim 24  wherein two of the assay chamber, the enzyme chamber, the blood chamber, and the agonist chamber are the same chamber.  
     
     
         28 . The device of  claim 24  wherein three of the assay chamber, the enzyme chamber, the blood chamber, and the agonist chamber are the same chamber.  
     
     
         29 . The device of  claim 24  wherein the assay chamber, the enzyme chamber, the blood chamber, and the agonist chamber are separate chambers.  
     
     
         30 . A system for monitoring COX1-inhibitor response comprising: 
 a fluid-tight material forming an assay chamber;    a pump functionally linked to the assay chamber for pumping fluids into the assay chamber;    a light detector functionally linked to the assay chamber for detecting light emitted in the assay chamber;    a fluid-tight material forming a blood chamber for holding blood, the blood chamber functionally linked to the pump;    a fluid-tight material forming an enzyme chamber for holding a solution of a light-producing ATP-consuming enzyme, the enzyme chamber functionally linked to the pump;    a fluid-tight material forming an agonist chamber for holding a solution of a COX1-dependent platelet agonist, the agonist chamber functionally linked to the pump;    a controller coupled to the pump and programmed to deliver to the assay chamber a predetermined volume of the blood, a predetermined volume of the light-producing enzyme solution, and a predetermined volume of the agonist solution; and    a display operably coupled to the light detector for displaying results from the light detector.    
     
     
         31 . The system of  claim 30  further comprising a valve functionally linked to the pump, the assay chamber, the blood chamber, the enzyme chamber, and the agonist chamber.  
     
     
         32 . The system of  claim 30  wherein the predetermined volume of blood is less than 40 μl.  
     
     
         33 . A kit for determining response to a COX1 inhibitor comprising: 
 a COX1-dependent platelet agonist;    an ATP-consuming enzyme; and    instruction means indicating that the enzyme and the agonist are to be used to determine a subject mammal's physiological response to a COX1 inhibitor.    
     
     
         34 . The kit of  claim 33  wherein the enzyme is a light-producing ATP-consuming enzyme.  
     
     
         35 . The kit of  claim 33  wherein the agonist is arachidonic acid.  
     
     
         36 . A kit for determining response to a COX1 inhibitor comprising: 
 (a) a device for monitoring COX1-inhibitor response comprising: 
 a fluid-tight material forming an assay chamber;  
 a pump functionally linked to the assay chamber for pumping fluids into the assay chamber;  
 a light detector functionally linked to the assay chamber for detecting light emitted in the assay chamber;  
 a fluid-tight material forming a blood chamber for holding blood, the blood chamber functionally linked to the pump;  
 a fluid-tight material forming an enzyme chamber for holding a solution of a light-producing ATP-consuming enzyme, the enzyme chamber functionally linked to the pump; and  
 a fluid-tight material forming an agonist chamber for holding a solution of a COX1-dependent platelet agonist, the agonist chamber functionally linked to the pump; and  
   (b) instruction means indicating that the device is to be used to determine a subject mammal's physiological response to a COX1 inhibitor.