Reagent and test cartridge for determining clotting time

Abstract

The invention is a method, reagent and test cartridge for the determination of the clotting time of a blood sample by means of a reagent containing tissue factor and a sulfatide. In an alternative embodiment, the reagent may contain tissue factor and at least one of the group consisting of a phosphatide and a sulfatide. This invention is preferably used to monitor the effectiveness of heparin therapy in patients that have been administered low to moderate heparin doses to achieve blood heparin levels from 0 to about 3 U/mL, and may also be used for determining clotting time at higher heparin levels of up to about 6 U/mL.

1 . A reagent for the determination of the clotting time of a blood sample from a patient receiving heparin treatment, wherein the clotting time is used to determine the effectiveness of the treatment, comprising tissue factor and a sulfatide in relative amounts sufficient to determine the effectiveness of heparin treatment in relation to clotting time in a sample from a patient receiving sufficient heparin to have a blood heparin level of up to about 6 U/mL.  
     
     
         2 . The reagent of  claim 1 , wherein said reagent is anhydrous.  
     
     
         3 . The reagent of  claim 1 , wherein said tissue factor is present in sufficient quantity in said reagent so that when an effective amount of said reagent is added to a blood sample to clot the sample, the sample comprises between about 50 and about 1000 ng/mL tissue factor.  
     
     
         4 . The reagent of  claim 3 , wherein a sample after contact with an effective amount of said reagent comprises about 100 ng/mL tissue factor.  
     
     
         5 . The reagent of  claim 1 , wherein said sulfatide is present in sufficient quantity in said reagent so that when an effective amount of said reagent is added to a blood sample to clot the sample, the sample comprises between about 1 and about 4 mg/mL sulfatide.  
     
     
         6 . The reagent of  claim 5 , wherein the sample after contact with an effective amount of said reagent comprises about 3 mg/mL sulfatide.  
     
     
         7 . The reagent of  claim 1 , wherein said reagent further comprises a buffer and a stabilizer.  
     
     
         8 . A test cartridge for the determination of the clotting time of a blood sample from a patient receiving heparin treatment, wherein the clotting time is used to determine the effectiveness of the treatment, comprising: 
 a housing containing an inlet port, a chamber unit, and an exit port, said inlet port, chamber unit, and exit port being present in a continuous capillary pathway; and    a reagent in said capillary pathway comprising tissue factor and a sulfatide    
     
     
         9 . The test cartridge according to  claim 8 , wherein said tissue factor is recombinant human tissue factor and said sulfatide is bovine brain sulfatide.  
     
     
         10 . The test cartridge of  claim 8 , wherein said tissue factor is present in sufficient quantity in said reagent so that when an effective amount of said reagent is contacted with a blood sample to clot the sample, the sample comprises between about 50 and about 1000 ng/mL tissue factor  
     
     
         11 . The test cartridge of  claim 10 , wherein a sample after contact with an effective amount of said reagent comprises about 100 ng/mL tissue factor.  
     
     
         12 . The test cartridge of  claim 8 , wherein said sulfatide is present in sufficient quantity in said reagent so that when an effective amount of said reagent is contacted with a blood sample to clot the sample, the sample comprises between about 1 and about 4 mg/mL sulfatide.  
     
     
         13 . The test cartridge of  claim 12 , wherein the sample after contact with an effective amount of said reagent comprises about 3 mg/mL sulfatide.  
     
     
         14 . The test cartridge according to  claim 8 , wherein said reagent further comprises a buffer and a stabilizer.  
     
     
         15 . A test cartridge for the determination of the clotting time of a blood sample from a patient receiving heparin treatment, wherein the clotting time is used to determine the effectiveness of the treatment, comprising: 
 a housing containing an inlet port, a chamber unit, an exit port, a first capillary unit for independently pumping a liquid from said inlet port to said chamber unit, and a second capillary unit positioned between and operatively connected to said chamber unit and said exit port for independently pumping a liquid from said chamber unit to said exit port; wherein said inlet port, first capillary unit, chamber unit, second capillary unit, and exit port are present in a continuous capillary pathway; and    a reagent in said capillary pathway comprising tissue factor and a sulfatide.    
     
     
         16 . A reagent for the determination of the effectiveness of heparin treatment in a patient receiving same, comprising tissue factor and at least one co-factor selected from the group consisting of a phosphatide and a sulfatide, wherein when a sufficient quantity of said reagent is contacted with a blood sample from a patient, clotting time can be used to determine to the effectiveness of heparin therapy to the patient.  
     
     
         17 . The reagent of  claim 16 , wherein said reagent is anhydrous.  
     
     
         18 . The reagent of  claim 16 , wherein said tissue factor is present in sufficient quantity in said reagent so that when an effective amount of said reagent is added to a blood sample to clot the sample, the sample comprises between about 50 and about 1000 ng/mL tissue factor.  
     
     
         19 . The reagent of  claim 18 , wherein the sample after contact with an effective amount of said reagent comprises about 100 ng/mL tissue factor.  
     
     
         20 . The reagent of  claim 16 , wherein said at least one co-factor selected from the group consisting of a phosphatide and a sulfatide is present in sufficient quantity in said reagent so that when an effective amount of said reagent is added to a blood sample to clot the sample, the sample comprises a combined total of said phosphatide and said sulfatide combined between about 1 and about 4 mg/mL.  
     
     
         21 . The reagent of  claim 20 , wherein the sample after contact with an effective amount of said reagent comprises a combined total of said phosphatide and said sulfatide of about 3 mg/mL.  
     
     
         22 . The reagent of  claim 16 , wherein said reagent further comprises a buffer and a stabilizer.  
     
     
         23 . A test cartridge for the determination of the effectiveness of heparin treatment in a patient receiving same, comprising: 
 a housing containing an inlet port, a chamber unit, and an exit port, said inlet port, chamber unit, and exit port being present in a continuous capillary pathway; and a reagent in said capillary pathway comprising tissue factor and at least one co-factor selected from the group consisting of a phosphatide and a sulfatide.    
     
     
         24 . The test cartridge according to  claim 23 , wherein said tissue factor is recombinant human tissue factor, said sulfatide is bovine brain sulfatide, and said phosphatide is phosphatidyl choline.  
     
     
         25 . The test cartridge of  claim 23 , wherein said tissue factor is present in sufficient quantity in said reagent so that when an effective amount of said reagent is contacted with a blood sample to clot the sample, the sample comprises between about 50 and about 1000 ng/mL tissue factor.  
     
     
         26 . The test cartridge of  claim 25 , wherein the sample after contact with an effective amount of said reagent comprises about 100 ng/mL tissue factor.  
     
     
         27 . The test cartridge of  claim 23 , wherein at least one co-factor from said group consisting of a phosphatide and a sulfatide is present in sufficient quantity in said reagent so that when an effective amount of said reagent is contacted with a blood sample to clot the sample, the sample comprises a combined total of said phosphatide and said sulfatide between about 1 and about 4 mg/mL.  
     
     
         28 . The test cartridge of  claim 27 , wherein the sample after contact with an effective amount of said reagent comprises a combined total of said phosphatide and said sulfatide of about 3 mg/mL.  
     
     
         29 . The test cartridge according to  claim 27 , wherein said reagent further comprises a buffer and a stabilizer.  
     
     
         30 . A reagent for use in determining the effectiveness of heparin treatment in patients receiving same, comprising a sulfatide and a phosphatide, wherein said sulfatide and said phosphatide are present in a ratio by weight of said phosphatide to said sulfatide of about 1/3 to about 3/1, and said reagent can determine heparin treatment effectiveness in patients receiving sufficient heparin to have blood heparin levels between about 0 U/mL and about 6 U/mL.  
     
     
         31 . The reagent of  claim 30 , further comprising tissue factor.  
     
     
         32 . A test cartridge for the determination of the effectiveness of heparin treatment in patients receiving same, comprising: 
 a housing containing an inlet port, a chamber unit, an exit port, a first capillary unit for independently pumping a liquid from said inlet port to said chamber unit, and a second capillary unit positioned between and operatively connected to said chamber unit and said exit port for independently pumping a liquid from said chamber unit to said exit port; wherein said inlet port, first capillary unit, chamber unit, second capillary unit, and exit port are present in a continuous capillary pathway; and    a reagent in said capillary pathway comprising tissue factor and a phosphatide.    
     
     
         33 . A reagent for use in determining the effectiveness of heparin treatment in patients receiving sufficient heparin to have a blood heparin level between about 0 U/mL and about 6 U/mL, comprising tissue factor and a cofactor, wherein, when an effective amount of said reagent is contacted with a blood sample from a patient having a blood heparin level between about 0 U/mL and about 6 U/mL, a predetermined degree of clotting is reached in less than about 300 seconds.  
     
     
         34 . The reagent of  claim 33 , wherein said cofactor comprises at least one of the group consisting of a sulfatide and a phosphatide.