Abstract Number: PB0895
Meeting: ISTH 2021 Congress
Theme: Platelet Disorders, von Willebrand Disease and Thrombotic Microangiopathies » Platelet Function Disorders, Hereditary
Background: Diagnosis of platelet function disorders relies on light-transmission aggregometry (LTA) using a panel of agonists. Hence, assessment of normal values and laboratory performances of the reagents used are critical for clinical practice.
Aims: The aim was to evaluate the performances of collagen, ADP, arachidonic acid, TRAP-6, and ristocetin reagents (Stago®, Asnières-sur-Seine, France) using LTA method in our laboratory.
Methods: LTA was performed on TA-8V aggregometer (SD-Medical, Stago®) on citrated platelet-rich plasma (PRP) obtained from 30 consenting healthy volunteers (NCT04269603), using 5 different agonists at several final concentrations: 2µg/mL collagen, 2 and 5µM ADP , 1mM arachidonic acid, 10µM TRAP-6 and 1.2 mg/mL ristocetin.
Normal values, intra-assay variability (CVintra, %) and inter-operator variability for maximal aggregation intensity (Imax, %) were measured after platelet activation by all agonists. Reagent stability was tested over a period of 2 months after reconstitution, sampling, and storage prior to use.
Results: Normal values for Imax ranged from >30% for 2µM ADP- to >80% for arachidonic acid- and ristocetin-induced platelet activation. Intra-assay variability was good, being below 8% in all conditions for platelet activation (range 2.7 – 7.8%). These results were in line with manufacturer’s normal values (when available; table1).
Inter-operator variability showed an agreement of >80% (range 84.6 – 100%) for all agonists tested, with regards to Imax values, and reached 100% when aggregation curves were examined by a blinded expert biologist. All reagents were stable for 2 months.
| Agonist | Imax normal values, % | CVintra, % | Stability after reconstitution and sampling, months (storage temperature) | |||
| Manufacturer | In house | Manufacturer | In house | Manufacturer | In house | |
| Collagen 2 µg/mL | >66 | >73 | 5.8 | 2.7 | ND | 2 (2-8°C) |
| ADP 2 µM | >47 | >30 | 6.4 | 7.8 | ND | 2 (-20°C) |
| ADP 5 µM | ND | >65 | ND | 3.1 | ND | 2 (-20°C) |
| Arachidonic acid 1 mM | >68 | >80 | 3.8 | 4.2 | ND | 2 (-20°C) |
| TRAP-6 10 µM | >69 | >66 | 4.2 | 5.7 | ND | 2 (-20°C) |
| Ristocetin 1.2 mg/ml | ND | >80 | ND | 2.5 | ND | 2 (-20°C) |
Maximum aggregation intensity (Imax) normal values and intra-assay variability (CV) of various agonist-induced platelet activation using TA-8V light-transmission aggregometer
ND: non determined
Conclusions: We provided normal range values and a study design for the assessment of laboratory performance of LTA method using collagen-, ADP-, arachidonic acid-, TRAP-6-, and ristocetin-agonists for platelet activation. The low CVintra, the good agreement between operators, and the 2-months period stability for all reagents tested, make them suitable for routine screening of platelet function disorders.
To cite this abstract in AMA style:
Dericquebourg A, Daniel M, Bordet J-, Sobas F, Nougier C, Negrier C, Le Quellec S. Light Transmission Aggregometry (LTA) on TA-8V (Stago®): What about Normal Values? [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/light-transmission-aggregometry-lta-on-ta-8v-stago-what-about-normal-values/. Accessed August 9, 2022.« Back to ISTH 2021 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/light-transmission-aggregometry-lta-on-ta-8v-stago-what-about-normal-values/