METHOD FOR ASSESSING THE FIBRINOGEN CONTRIBUTION IN COAGULATION
The present invention is directed to a diagnostic method for the determination of a coagulopathy in a patient, in particular, for calculating the individual need of blood components, preferably blood platelets and/or fibrinogen and/or Factor XIII, which has to be substituted in a patient.
1 . A diagnostic method for the determination of a coagulopathy in a patient, comprising the steps of:
a) obtaining a blood sample from a patient;
b) adding a coagulation component inhibitor to the sample in a suitable amount for inhibiting said coagulation component;
c) performing a viscoelastometric measurement in the blood sample under suitable conditions in a suitable apparatus;
d) comparing the results obtained in step c) with those from other donors;
wherein the results are indicative for the presence of a coagulopathy and enable the assessment of amount of coagulation component to be administered to the patient to balance haemostasis.
2 . The method of claim 1 , wherein the viscoelastometric measurement performed in step c) comprises the determination of at least one of the following coagulation characteristics: clotting time, clot formation time, firmness of the clot over time, maximum clot firmness or fibrinolysis extent.
3 . The method of claim 1 , wherein the coagulation component inhibitor is a platelet inhibitor and is selected from the group of cyto-skeletton inhibitors and/or GPIIb/IIIa antagonists, and preferably is cytochalasin D, abciximab, or a mixture thereof.
4 . The method of claim 1 , wherein prior to step c) a further agent able to polymerize and thereby to increase the blood clot firmness is added in a predefined amount to the sample.
5 . The method of claim 4 , wherein the agent which is able to polymerize and thereby to increase the blood clot firmness is fibrinogen.
6 . The method of claim 1 , wherein prior to step c) a further agent able to enhance the polymerization effects and thereby to increase the blood clot firmness is added in a predefined amount to the sample.
7 . The method of claim 6 , wherein the agent which is able to enhance the polymerization effects and thereby to increase the blood clot firmness is Factor XIII.
8 . The method of claim 1 , wherein, subsequently, a further diagnostic method is performed, wherein steps c) and d) are applied to untreated blood samples, wherein differing results are indicative for the presence of a coagulopathy.
9 . The method of claim 1 , wherein from the results obtained in step d) and optionally based on further parameters, the amount of blood components to be substituted to the patient is calculated.
10 . The method of claim 9 , wherein the further parameters comprise the overall blood volume and the body weight of the patient.
11 . The method of claim 9 , wherein the blood components comprise blood platelets and/or fibrinogen.
12 . The method of claim 1 , wherein the determination in step c) and d) is performed by an apparatus suitable for performing a viscoelastometric analysis.
13 . The method of claim 12 , wherein the apparatus is a thromboelastometer or a thrombelastograph.
14 . The method of claim 1 , wherein the blood sample is obtained from a mammal.
15 . The method of claim 14 , wherein the blood sample is obtained from a human patient.
16 . The method of claim 15 , wherein the blood sample is whole blood or blood plasma.
17 . The method of claim 1 , wherein an activator of coagulation is added to the blood sample.
18 . The method of claim 1 , wherein prior to the determination performed in steps c) and d), one or more of the following ingredients are added to the blood sample:
at least one activator of coagulation;
a calcium salt, preferably CaCl 2 ;
one or more coagulation components or factors.
19 . The method of claim 18 , wherein the activator of coagulation is an intrinsic and/or extrinsic activator.
20 . The method of claim 18 or 19 , wherein the extrinsic activator of coagulation is the Tissue Factor (TF).
21 . The method of claim 20 , wherein the Tissue Factor is selected from lipidated TF or rTF.
22 . The method of claim 19 , wherein the intrinsic activator of coagulation is selected from the group consisting of celite, ellagic acid, sulfatit, kaolin, silica, RNA, or mixtures thereof.
23 . The method of claim 17 , wherein the activator of coagulation is selected from one or more coagulation factors or activated coagulation factors, preferably FXa or FVa or activated protein C or FVIIa.
24 . The method of claim 17 or 18 , wherein CaCl 2 is present in an amount of about 1-100 μmol/ml of the blood sample.
25 . The method of claim 1 , wherein the contribution of the agent, which is able to polymerize, to the viscoelastic parameters determined in steps c) and d), is subtracted from the results by a suitable algorithm.