Abstract Number: PB0870
Meeting: ISTH 2021 Congress
Theme: Platelet Disorders, von Willebrand Disease and Thrombotic Microangiopathies » Inherited Thrombocytopenias
Background: The mechanisms of platelet dysfunction in patients with ANKRD26 associated thrombocytopenia (ANKRD26-AT) are still poorly understood.
Aims: The aim of this work is to detect possible morpho-functional disorders of platelets in children with ANKRD26-AT by flow cytometry with activation.
Methods: 8 children with median age of 6 years (range 1.5 to 15 years) with confirmed ANKRD26-AT by Next Generation Sequencing (NGS) were examined. The platelet count ranged from 29 to 172×109 / L, with a median of 60×109 / L. The severity of hemorrhagic manifestations was assessed on a standardized scale (Pediatric Bleeding Questionnaire, PBQ) and it ranged from 0 to 5 score, with a median of 3.5 score. We investigated morphology of platelets by FSC and SSC, CD42b receptor and phosphatidylserine-positive platelets, at rest and after activation. Platelet activation was performed with a CRP + TRAP mixture. Comparison was carried out with the results of examination of 26 apparently healthy children (control group – CG) with median age of 7 years (range 2 to 15 years).
Results: 
Figure A-D. Integral assessment of morphological characteristics of platelet size and granularity at rest and after activation.
Figure E-H. Differences in CD42b receptor density and proportion of phosphatidylserine-positive platelets.At rest, CG-platelets did not show significant differences by FSC, SSC, CD42b and procoagulant platelet count (p>0.05) compared with patients (fig. A, C, E and G, respectively). After activation, ANKRD-26 platelets demonstrated an increased platelet size (FSC, p = 0.018, fig. B) and granularity (SSC, p<0.001, fig. D), an increased density of CD42b (p <0.001, fig. F) and a decrease in the proportion of procoagulant platelets (p = 0.01, fig. H).
Conclusions: These changes potentially indicate disturbed mechanisms of activation and shape changes of platelets in patients with ANKRD26-AT.
To cite this abstract in AMA style:
Polokhov D, Fedorova D, Pshonkin A, Ignatova A, Ponomarenko E, Aleksenko M, Mersiyanova I, Seregina E, Voronin K, Poletaev A, Raykina E, Panteleev M, PZ. Disturbed Platelet Activation in Children with ANKRD26-associated Thrombocytopenia [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 1). https://abstracts.isth.org/abstract/disturbed-platelet-activation-in-children-with-ankrd26-associated-thrombocytopenia/. Accessed September 24, 2021.« Back to ISTH 2021 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/disturbed-platelet-activation-in-children-with-ankrd26-associated-thrombocytopenia/