Determination of thromboelastographic responsiveness in stored single-donor platelet concentrates

Thromboelastography (TEG) is widely used in hospitals but less commonly in blood banks for evaluation of platelet (PLT) concentrates (PCs). A TEG-PC assay for testing fresh or stored PLTs must reflect the quality of the PLTs. The added value could be measurement of donor-dependent PLT quality.

Whole blood (WB) normal values were generated from 100 donors, using standard tests. Nineteen single-donor PCs were evaluated with a TEG-PC assay, using Octaplas as microparticle-free diluent and kaolin or collagen as activator, stored up to 12 days, and also sampled for additional in vitro tests.

WB values showed larger reaction rates (R- and K-times, angle) compared to the reference values and almost similar maximum amplitude (MA). PCs showed usual storage lesion and TEG-PC results showed significant decreasing R- and K-times and increasing angle. Mean MA values remained constant but individual measurements were affected by clot retraction. TEG tracings of two PCs with good quality on Day 12 showed weak to strong clot retraction, while two PCs with poor quality showed moderate clot retraction on Day 1, no clot retraction on Days 5 to 12, and a decreased MA on Day 12. Clot strength (MA) and especially clot retraction represent possibly donor-specific effects.

A TEG-PC assay has been developed that is sensitive to storage effects. The assay has the potential to be helpful in selection of PLT donors but needs improvement to be more sensitive, reproducible, and distinctive to determine whose PLTs store poorly and whose store well.