Development of novel automated screening method for detection of fviii inhibitors

Abstract

Disclosed herein are methods for determining the presence of a coagulation inhibitor in a patient. A patient curve associated with the patient sample and having a patient slope (Ps) and a a standard curve associated with a control sample and having a control slope (Cs) are generated, and the Ps and the Cs are compared to obtain a Ps/Cs parallelism ratio. A Ps/Cs parallelism ratio of less than a predetermined ratio is indicative of presence of a coagulation inhibitor in the patient sample.

1 . A method of determining the presence of a Factor VIII inhibitor in a patient sample, the method comprising:
 generating a patient curve associated with a patient sample and having a patient slope (Ps);   generating a standard curve associated with a control sample and having a control slope (Cs),
 wherein the Ps and Cs curves are generated by plotting a plurality of clotting time points for a series of dilutions of the patient sample and the control sample relative to FVIII clotting activity; and 
   comparing the Ps and the Cs to obtain a Ps/Cs parallelism ratio, wherein a Ps/Cs parallelism ratio of less than about 0.45 is indicative of presence of a Factor VIII inhibitor in the patient sample.   
     
     
         2 . The method of  claim 1 , wherein the Ps/Cs parallelism ratio is determined by a microprocessor in electronic communication with a clotting detection machine. 
     
     
         3 . The method of  claim 1 , further comprising the step of:
 in response to determining the Ps/Cs parallelism ratio of less than 0.45, administering to the patient at least one agent for treatment of a condition associated with the presence of the Factor VIII inhibitor.   
     
     
         4 . The method of  claim 3 , wherein the condition is hemophilia A. 
     
     
         5 . The method of  claim 3 , wherein the condition is an autoimmune disorder. 
     
     
         6 . The method of  claim 3 , wherein the agent is one or more of the following: human factor VIII, porcine factor VIII, and an FVIII bypassing agent. 
     
     
         7 . The method of  claim 2 , further comprising the step of:
 producing an output by the microprocessor, the output being capable of perceived visually or audibly by a human user or as digital information readable by a computer, wherein the output comprises an indication of the Ps/Cs ratio.   
     
     
         8 . A method of determining the presence of a coagulation inhibitor in a patient sample, said method comprising:
 generating a patient curve associated with the patient sample and having a patient slope (Ps);   generating a standard curve associated with a control sample and having a control slope (Cs), wherein the Ps and Cs curves are generated by plotting a plurality of clotting time points for a series of dilutions of the patient sample and the control sample relative to clotting activity; and   comparing the Ps and the Cs to obtain a Ps/Cs parallelism ratio, wherein a Ps/Cs parallelism ratio of less than a predetermined ratio is indicative of presence of a coagulation inhibitor in the patient sample.   
     
     
         9 . The method of  claim 8 , wherein the predetermined ratio is about 0.45. 
     
     
         10 . The method of  claim 8 , wherein the coagulation inhibitor is dabigatran. 
     
     
         11 . The method of  claim 8 , wherein the coagulation inhibitor is Factor VIII inhibitor. 
     
     
         12 . (canceled) 
     
     
         13 . A method of determining the presence of an anti-coagulating compound in a patient sample and treating such patient, said method comprising:
 obtaining a patient sample of the bodily fluid;   detecting whether an anti-coagulating compound is present in the patient sample by:
 generating a patient curve associated with the patient sample and having a patient slope (Ps); 
 generating a standard curve associated with a control sample and having a control slope (Cs), wherein the Ps and Cs curves are generated by plotting a plurality of clotting time points for a series of dilutions of the patient sample and the control sample relative to the clotting activity; and 
 comparing the Ps and the Cs curves to obtain a Ps/Cs parallelism ratio, wherein a Ps/Cs parallelism ratio of less than a predetermined ratio is indicative of presence of an anti-coagulating compound in the patient sample; and 
   administering an effective amount of a coagulating agent to the patient, in response to a Ps/Cs parallelism ratio being less than a predetermined ratio.   
     
     
         14 . The method of  claim 13 , wherein the predetermined ratio is about 0.45. 
     
     
         15 . The method of  claim 13 , wherein the anti-coagulating compound is Factor VIII inhibitor. 
     
     
         16 . The method of  claim 15 , wherein the coagulating agent is mammalian Factor VIII. 
     
     
         17 . The method of  claim 13 , wherein the anti-coagulating compound is dabigatran. 
     
     
         18 . The method of  claim 17 , wherein the coagulating agent is idarucizumab. 
     
     
         19 . The method of  claim 13 , wherein the anti-coagulating compound is rivaroxaban. 
     
     
         20 . The method of  claim 19 , wherein the coagulating agent is nonactivated Prothrombin Complex Concentrate. 
     
     
         21 . The method of  claim 8 , wherein the coagulation inhibitor is rivaroxaban.