The effect of selected pre-analytical phase variables on plasma thromboxane A₂ measurements in humans.
OBJECTIVE
Platelet function testing is often affected by the existence of different pre-analytical variables that can cause platelet activation. The aim of this study was to assess the effect of such variables that are present when samples are taken (different anticoagulants, incubation temperature, and storage conditions) to select those which enable to reach optimal range of measured plasma concentrations of the two stable thromboxane A₂ metabolites, that is, thromboxane B₂ (TxB₂) and 11-dehydrothromboxane B₂ (11-dTxB₂).


METHODS
For the purpose of this study, whole blood samples obtained from 20 volunteers were screened for TxB₂ and 11-dTxB₂ concentrations using commercial EIA kits (Cayman Chemicals™; Neogen™) in relation to the effect of different anticoagulants, using different incubation temperatures and storage conditions.


RESULTS
Trisodium citrate has been shown not to be affecting the TxB₂ and 11-dTxB₂ concentrations compared with the values measured in the serum. Incubation of the samples for 1 h at 37 °C and freezing at -20 °C or -80 °C give the most suitable concentration range of both thromboxanes in the used EIA measurement.


CONCLUSIONS
This study describes the setup of such pre-analytical phase conditions that enable the screening of platelet function in terms of the plasma concentrations of TxB₂ and 11-dTxB₂ in selected EIA measurement.
Division of Clinical Pharmacology of the Department of Medicine I, Thomayer Hospital, Prague, Czech Republic. sadilkova@biomed.cas.cz
L
L
Sadilkova
Z
Z
Paluch
J
J
Mottlova
F
F
Bednar
S
S
Alusik
D000925:Anticoagulants / Q000494:pharmacology; D001241:Aspirin / Q000627:therapeutic use; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D002951:Citrates / Q000494:pharmacology; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D006801:Humans; D007124:Immunoenzyme Techniques; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D013048:Specimen Handling; D013696:Temperature; D013928:Thromboxane A2 / Q000097:blood* / Q000378:metabolism; D013929:Thromboxane B2 / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism; D013997:Time Factors
D000925:Anticoagulants; D002951:Citrates; D016861:Cyclooxygenase Inhibitors; D010975:Platelet Aggregation Inhibitors; C514290:trisodium citrate; D013929:Thromboxane B2; D013928:Thromboxane A2; C049235:11-dehydro-thromboxane B2; D001241:Aspirin