Lupus anticoagulant (la) mixing method and kit with reduced factor deficiency effect and reduced inhibitor interference for identifying la associated with antiphospholipid syndrome

Abstract

The invention described herein relates to a kit for the diagnosis of antiphospholipid syndrome in patients, wherein a coagulation inhibitor and normal pooled plasma mixture reduce the factor deficiency effect of patient plasma, and coagulation inhibitor interference in patient plasma, and increases specificity and the sensitivity for detecting lupus anticoagulants in the patient's blood in a phospholipid-dependent clotting assay.

We claim: 
     
         1 . A kit for detecting lupus anticoagulants associated with antiphospholipid syndrome in a patient, comprising:
 a) a phospholipid-dependent clotting reagent comprising a low concentration of phospholipid;   b) at least one coagulation inhibitor; and,   c) said phospholipid-dependent clotting reagent comprising a concentration of phospholipid that is higher than the concentration of phospholipids in a).   
     
     
         2 . The kit of  claim 1  further comprising normal pooled plasma. 
     
     
         3 . The kit of  claim 1  wherein said phospholipid-dependent clotting reagent comprises APTT. 
     
     
         4 . The kit of  claim 1  wherein said phospholipid-dependent clotting reagent is selected from the group consisting of dRVVT, APTT-based platelet neutralization procedure (PNP), APTT-based hexagonal phase phospholipid neutralization test, APTT-based kaolin clotting time (KCT), APTT-based silica clotting time (SCT) and dilute prothrombin time (dPT). 
     
     
         5 . The kit of  claim 1  wherein said at least one coagulation inhibitor comprises at least one thrombin inhibitor. 
     
     
         6 . The kit of  claim 5  wherein said at least one thrombin inhibitor is selected from the group consisting of d-phenylalanyl-1-prolyl-1-arginine-chloromethyl ketone (PPACK), I-2581, hirudin, hirudin derivatives, lepirudin, desirudin, hirudin analogues, bivalirudin, argatroban, melagatran, dabigatran, and combinations thereof. 
     
     
         7 . The kit of  claim 1  wherein said at least one coagulation inhibitor comprises at least one factor Xa inhibitor, selected from the group consisting of rivaroxaban, apixaban, edoxaban, betrixaban, antistasin, Tick Anticoagulant Protein (TAP) and combinations thereof. 
     
     
         8 . The kit of  claim 1  wherein said coagulation inhibitor and said phospholipid-dependent clotting reagent comprising said low concentration of phospholipid are packaged in the same container. 
     
     
         9 . The kit of  claim 1  wherein said coagulation inhibitor and said phospholipid-dependent clotting reagent comprising said high concentration of phospholipid are packaged in the same container. 
     
     
         10 . The kit of  claim 2  wherein said normal pooled plasma is packaged in the same container as said coagulation inhibitor. 
     
     
         11 . The kit of  claim 1  wherein said low concentration of phospholipid comprises a range of about 0.002 (g/l) to about 0.2 (g/l). 
     
     
         12 . The kit of  claim 1  wherein said higher concentration of phospholipid comprises a range of about 0.2 (g/l) to about 5.0 (g/l). 
     
     
         13 . A kit for detecting lupus anticoagulants associated with antiphospholipid syndrome in a patient, comprising:
 at least one coagulation inhibitor; and   normal pooled plasma.