Method of measuring platelet activation
Platelet activation is measured by determining Mean Platelet Component (MPC) of suspended blood platelets, using a specific anticoagulant composition. The composition comprises at least one component for effecting platelet sphering (for example EDTA), and at least one platelet antagonist (for example at least one of, and preferably all three of theophylline, adenosine and dipyridamole).
1. A method of measuring leucocyte activation, comprising measuring a leucocyte activation indicator of leucocytes suspended in a blood anticoagulant composition comprising one or more components for effecting platelet sphering, and two or more of:
(a) theophylline,
(b) adenosine and/or 2-chloroadenosine,
(c) dipyridamole, and
(d) citrate.
2. A method of measuring platelet activation, comprising determining mean refractive index of blood platelets suspended in a composition comprising at least one component for effecting platelet sphering comprising EDTA, EGTA or a combination thereof, and at least one platelet antagonist.
3. The method of claim 2 , wherein said at least one platelet antagonist comprises:
a) theophylline,
b) adenosine and/or 2-chloroadenosine, or
c) dipyridamole.
4. The method of claim 2 , wherein said at least one platelet antagonist comprises two or more of
a) theophylline,
b) adenosine and/or 2-chloroadenosine, and
c) dipyridamole.
5. The method of claim 2 , wherein said at least one platelet antagonist comprises:
a) theophylline,
b) adenosine and/or 2-chloroadenosine, and
c) dipyridamole.
6. The method of claim 2 , wherein said at least one platelet antagonist comprises:
a) theophylline,
b) adenosine, and
c) dipyridamole.
7. The method of any one of claims 3 to 6 wherein the composition further comprises citrate.
8. The method of claim 2 , wherein said component for effecting platelet sphering comprises EDTA, said at least one platelet antagonist comprises theophylline, adenosine and dipyridamole and said composition further comprises citrate.
9. The method of claim 2 , wherein the mean refractive index is determined by measuring light scatter at two different angles to an incident light beam.
10. The method of claim 9 , wherein the two different angles are angles of 2–3 degrees and 5–15 degrees to the direction of the incident light beam.
11. The method of claim 2 , wherein said refractive index determination is carried out at a time of from 30 to 60 minutes after a venesection.
12. The method of claim 2 , wherein an anticoagulated blood sample is maintained at a temperature of 0°C. to 10°C. between a venesection and said determining.
13. The method of claim 1 , wherein the two or more other components comprise three or more of
a) theophylline,
b) adenosine and/or 2-chloroadenosine,
c) dipyridamole, and
d) citrate.
14. The method of claim 1 , wherein the two or more other components comprise
a) theophylline,
b) adenosine and/or 2-chloroadenosine,
c) dipyridamole, and
d) citrate.
15. The method of any one of claims 1 , 13 and 14 , wherein the one or more components for effecting platelet sphering comprises a chelating agent.
16. The method of claim 15 , wherein the chelating agent is one or both of EDTA and EGTA.
17. The method of claim 16 , wherein the blood anti-coagulant composition comprises a mixture of EDTA and CTAD.
18. A method of maintaining a blood sample in an anticoagulated state between venesection and measurement of platelet activation, comprising preparing a composition comprising a whole blood sample and a blood anticoagulant composition comprising EDTA or EGTA or a combination thereof, and CTAD.
19. A blood anticoagulant composition comprising one or more components for effecting platelet sphering comprising EDTA or EGTA, or a combination thereof, and wherein said composition also comprises citrate, theophylline, dipyridamole, and adenosine and/or 2-chloroadenosine.
20. The composition of claim 19 , which comprises EDTA and CTAD.
21. A method of measuring leucocyte activation, comprising measuring a leucocyte activation indicator of leucocytes suspended in a blood anticoagulant composition comprising one or more components for effecting platelet sphering including EDTA and/or EGTA; and:
(a) theophylline,
(b) adenosine and/or 2-chloroadenosine, and
(c) citrate.
22. A blood anticoagulant composition comprising one or more components for effecting platelet sphering including EDTA and/or EGTA; and:
(a) theophylline,
(b) adenosine at a concentration of 0.01 mM to 3.7 mM,
(c) citrate, and
(d) dipyridamole.
23. The composition of claim 22 comprising a mixture of EDTA and CTAD.
24. A method of measuring platelet count, wherein platelet count is measured on platelets suspended in an anticoagulant composition of claim 19 or claim 22 .
25. A method of measuring platelet activation, comprising measuring a platelet activation indicator of platelets suspended in the anticoagulant composition of claim 19 or claim 22 .
26. The method of claim 25 , wherein an anticoagulated blood sample is maintained at a temperature of 0°C. to 10°C. between a venesection and a measurement.
27. The method of claim 25 , wherein the method comprises measuring CD62P expression of the platelets.
28. The method of claim 25 , wherein the method comprises determining the mean refractive index of the platelets.
29. The method of claim 28 , wherein the mean refractive index is determined by measuring light scatter at two different angles to an incident light beam.
30. The method of claim 29 , wherein the two different angles are angles of 2–3 degrees and 5–15 degrees to the direction of the incident light beam.
31. The method of claim 28 , wherein said refractive index determination is carried out at a time of from 30 to 60 minutes after a venesection.
32. A method of maintaining a blood sample in an anticoagulated state between venesection and measurement of platelet activation, comprising preparing a composition comprising a blood sample and the blood anticoagulant composition of claim 19 or claim 22 .