Methodologies and reagents for detecting fibrinolysis and hyperfibrinolysis in a blood sample using viscoelastic analysis
In some embodiments, the invention provides methods for detecting fibrinolysis or hyperfibrinolysis in a blood sample from a patient. The method includes subjecting a first portion of a blood sample comprising reduced platelet function to viscoelastic analysis in the absence of an inhibitor of fibrinolysis to obtain a coagulation characteristic of the first portion at a time point; and subjecting a second portion of the blood sample comprising reduced platelet function to viscoelastic analysis in the presence of an inhibitor of fibrinolysis to obtain a coagulation characteristic of the second portion at the time point; wherein a difference between the coagulation characteristic of the first portion and the coagulation characteristic of the second portion indicates fibrinolysis or hyperfibrinolysis in the blood sample.
1. A method for detecting fibrinolysis or hyperfibrinolysis in a blood sample, comprising:
a) subjecting a first portion of a blood sample comprising reduced platelet function, to viscoelastic analysis in the absence of an inhibitor of fibrinolysis to obtain a coagulation characteristic of the first portion at a selected time point;
b) subjecting a second portion of the blood sample comprising reduced platelet function to viscoelastic analysis in the presence of an inhibitor of fibrinolysis to obtain a coagulation characteristic of the second portion at the selected time point; and
c) comparing the coagulation characteristic of the first portion to the coagulation characteristic of the second portion to detect a difference;
wherein a difference between the coagulation characteristic of the first portion and the coagulation characteristic of the second portion indicates fibrinolysis or hyperfibrinolysis in the blood sample.
2. The method of claim 1 , wherein the coagulation characteristic is an amplitude of an output of the viscoelastic analysis.
3. The method of claim 1 , wherein the coagulation characteristic is a first derivative of an amplitude of an output of the viscoelastic analysis.
4. The method of claim 1 , wherein the time point is at a time of maximum clot strength of the first portion.
5. The method of claim 1 , wherein the time point is between about 15 to about 35 minutes after the viscoelastic analysis is started.
6. The method of claim 1 , wherein the time point is less than 20 minutes after the viscoelastic analysis is started.
7. The method of claim 1 , wherein the time point is obtained is at a time that clot firmness reaches 20 mm in the first portion of the blood sample.
8. The method of claim 1 , wherein the difference between the coagulation characteristic of the first portion and the coagulation characteristic of the second portion that is at least 1% indicates fibrinolysis or hyperfibrinolysis in the blood sample.
9. The method of claim 1 , wherein the difference between the coagulation characteristic of the first portion and the coagulation characteristic of the second portion that is at least 2% indicates fibrinolysis or hyperfibrinolysis in the blood sample.
10. The method of claim 1 , wherein the blood sample comprising reduced platelet function comprises an inhibitor of platelet function.
11. The method of claim 10 , wherein the inhibitor of platelet function is a glycoprotein IIb/IIIa receptor inhibitor.
12. The method of claim 11 , wherein the glycoprotein IIb/IIIa receptor inhibitor is selected from the group consisting of abciximab, eptifibatide, and tirofiban.
13. The method of claim 10 , wherein the inhibitor of platelet function is an adenosine diphosphate (ADP) receptor inhibitor, adenosine reuptake inhibitor, or a thromboxane inhibitor.
14. The method of claim 10 , wherein the inhibitor of platelet function is cytochalasin D.
15. The method of claim 1 , wherein the blood sample comprising reduced platelet function is a platelet-reduced blood sample.
16. The method of claim 15 , wherein the platelet-reduced blood sample is obtained by physical removal of the platelets from the blood sample.
17. The method of claim 1 , wherein the inhibitor of fibrinolysis is tranexamic acid.
18. The method of claim 1 , wherein the inhibitor of fibrinolysis is selected from the group consisting of consisting of aminocaproic acid (ε-aminocaproic acid) and aprotinin.
19. The method of claim 1 , wherein the viscoelastic analysis is performed using a hemostasis analyzer.
20. The method of claim 1 , wherein the viscoelastic analysis is performed using a container containing the sample on an interior of the container and a pin, wherein the pin moves relative to the container.
21. The method of claim 1 , wherein the viscoelastic analysis is performed using a container containing the sample on an interior of the container and a pin, wherein the container moves relative to the pin.
22. The method of claim 1 , wherein the inhibitor of fibrinolysis is included in a coating on an interior of a container containing the sample.
23. The method of claim 1 , wherein the inhibitor of fibrinolysis is added to the sample.
24. The method of claim 10 , wherein the inhibitor of platelet function is included in a coating on an interior of a container containing the sample.
25. The method of claim 10 , wherein the inhibitor of platelet function is added to the sample.
26. The method of claim 1 , wherein the blood sample is obtained from a patient.
27. The method of claim 26 , wherein if fibrinolysis or hyperfibrinolysis is detected, the patient is responsive to the inhibitor of fibrinolysis.
28. A method for identifying an inhibitor of fibrinolysis that will achieve a beneficial response in a patient undergoing or likely to undergo fibrinolysis or hyperfibrinolysis, comprising:
a) subjecting a first portion of a blood sample comprising reduced platelet function from the patient to viscoelastic analysis in the absence of an inhibitor of fibrinolysis to obtain a coagulation characteristic of the first portion at a selected time point;
b) subjecting a second portion of the blood sample comprising reduced platelet function from the patient to viscoelastic analysis in the presence of a first inhibitor of fibrinolysis to obtain a coagulation characteristic of the second portion at the selected time point;
c) subjecting a third portion of a blood sample comprising reduced platelet function from the patient to viscoelastic analysis in the presence of a second inhibitor of fibrinolysis to obtain a coagulation characteristic of the third portion at the selected time point; and
d) comparing a first difference between the coagulation characteristic of the first portion and the coagulation characteristic of the second portion in the presence of the first inhibitor, and a second difference between the coagulation characteristic of the first portion and the coagulation characteristic of the third portion in the presence of the second inhibitor,
wherein the patient will have a beneficial result from treatment with the first inhibitor if the first difference is greater than the second difference, and the patient will have a beneficial result from treatment with the second inhibitor if the second difference is greater than the first difference.
29. The method of claim 28 , wherein the patient is human.
30. The method of claim 28 , wherein the first inhibitor of fibrinolysis is tranexamic acid.
31. The method of claim 28 , wherein each of the first inhibitor of fibrinolysis and the second inhibitor of fibrinolysis is selected from the group consisting of ε-aminocaproic acid, tranexamic acid, and aprotinin, wherein the first inhibitor of fibrinolysis and the second inhibitor of fibrinolysis are not the same.
32. The method of claim 1 , wherein the inhibitor of fibrinolysis is a combination of two or more inhibitors selected from the group consisting of aminocaproic acid (ε-aminocaproic acid), tranexamic acid, and aprotinin.
33. The method of claim 10 , wherein the inhibitor of platelet function is a combination of two or more different inhibitors selected from the group consisting of abciximab, eptifibatide, tirofiban, an adenosine diphosphate (ADP) receptor inhibitor, an adenosine reuptake inhibitor, a thromboxane inhibitor and cytochalasin D.