Published in:
British Journal of Haematology, 162 (2013) 5, Seite 684-692
Language:
English
DOI:
10.1111/bjh.12443
ISSN:
0007-1048;
1365-2141
Origination:
Footnote:
Description:
<jats:title>Summary</jats:title><jats:p>Pseudothrombocytopenia remains a challenge in the haematological laboratory. The pre‐analytical problem that platelets tend to easily aggregate <jats:italic>in vitro</jats:italic>, giving rise to lower platelet counts, has been known since ethylenediamine‐tetra acetic acid <jats:styled-content style="fixed-case">EDTA</jats:styled-content> and automated platelet counting procedures were introduced in the haematological laboratory. Different approaches to avoid the time and temperature dependent <jats:italic>in vitro</jats:italic> aggregation of platelets in the presence of <jats:styled-content style="fixed-case">EDTA</jats:styled-content> were tested, but none of them proved optimal for routine purposes. Patients with unexpectedly low platelet counts or flagged for suspected aggregates, were selected and smears were examined for platelet aggregates. In these cases patients were asked to consent to the drawing of an additional sample of blood anti‐coagulated with a magnesium additive. Magnesium was used in the beginning of the last century as anticoagulant for microscopic platelet counts. Using this approach, we documented 44 patients with pseudothrombocytopenia. In all cases, platelet counts were markedly higher in samples anti‐coagulated with the magnesium containing anticoagulant when compared to <jats:styled-content style="fixed-case">EDTA</jats:styled-content>‐anticoagulated blood samples. We conclude that in patients with known or suspected pseudothrombocytopenia the magnesium‐anticoagulant blood samples may be recommended for platelet counting.</jats:p>