PB0777 - Platele's function and sialylation in aged individuals

Monday, June 24, 2024

13:45 – 14:45 ICT

Room: Exhibition Hall

Presenting Author(s)

EM

Elena Monzón Manzano

Researcher
Department of Haematology, Hospital Universitario La Paz, Madrid, Spain. IdiPAZ, Madrid, Spain
Madrid, Madrid, Spain

Co-Author(s)

María Teresa Alvarez-Román, MD, PhD

Head of the Haemostasis Unit
Department of Hematology, University Hospital La Paz, Autonoma University of Madrid, Madrid, Spain
Madrid, Madrid, Spain
CH

Carmen Herrero Carrasco

Clinician
Hospital Severo Ochoa
Madrid, Madrid, Spain
PA

Paula Acuña Butta

researcher
Department of Haematology, Hospital Universitario La Paz-IdiPaz
Madrid, Madrid, Spain
Elena G.Arias Salgado

Researcher
Grupo de Coagulopatías y Trastornos de la Hemostasia, IdiPaz, Madrid, Spain
Madrid, Madrid, Spain
RR

Raquel Ramirez Martín

Clinician
Department of Geriatrics, Hospital Universitario La Paz- IdiPaz
Madrid, Madrid, Spain
MM

Mónica Martín Salces

Clinician
Department of Haematology, Hospital Universitario La Paz-IdiPaz
Madrid, Madrid, Spain
IR

Isabel Rivas Pollmar

Clinician
Department of Haematology, Hospital Universitario La Paz-IdiPaz
Madrid, Madrid, Spain
Víctor Jiménez-Yuste

Head of Hematology Service
Hospital Universitario La Paz-IdiPaz
Madrid, Madrid, Spain
PS

Pedro Sanchez Godoy

Clinician
Hospital Severo Ochoa
Madrid, Madrid, Spain
NB

Nora Butta

Researcher
Grupo de Coagulopatías y Trastornos de la Hemostasia, IdiPaz, Madrid, Spain
Madrid, Madrid, Spain

Background: Physiological changes occur in all organ systems during aging, and platelets may not escape this transformation.

Aims: To compare features of platelets from individuals ≤65 and >65 years old (yo).

Methods: We included 100 individuals >18 to ≤65, and 50 >65 yo. Individuals with cardiovascular disease, previous thrombotic events, blood disease or under treatment with antiaggregants were excluded.
Platelet activation markers and receptors were determined in diluted platelet rich plasma. Platelets were incubated with 100 µmol/L TRAP and either FITC-PAC1 (a mAb that recognizes activated conformation of fibrinogen receptors), or FITC-anti-P-selectin mAb or FITC-anti-CD63 mAb. To determine platelet receptors, PE-anti-CD41, FITC-anti-CD61, FITC-anti-CD42a and FITC-anti-CD43b mAbs were added. These samples and active caspase-3, -8 or -9 were evaluated by flow cytometry.
Lectin binding studies were performed in washed platelets incubated with FITC- Ricinus Communis Agglutinin (RCA) to indirectly determine sialic acid since it binds to galactose residues; and Wheat Germ Agglutinin (WGA) that binds to ß-GlcNac. Neuraminidase 1 (Neu1) on platelet`s surface was determined with FITC-anti-Neu1 mAb and samples were analysed by flow cytometry.
Informed consent was obtained and the study was approved by Ethics Committee of Hospital Universitario La Paz.

Results: Platelets from individuals >65 yo had a reduced ability to be activated (Figure 1A) that was not due to a reduction in fibrinogen and von Willebrand receptors. No differences between both groups were observed in caspases activities.
Platelets from >65 yo individuals bound less WGA and RCA. Reduced binding of RCA indicated higher content of sialic acid, that might be related to the reduced exposure of Neu1 on platelet’s surface (Figure 1B).

Conclusion(s): Aging seemed to reduce platelet’s function and to produce changes in platele's glycome.

Work supported by Instituto de Salud Carlos III (PI22/01489), co-funded by the European Union; by Beca Luis Álvarez 2022 from IdiPAZ and by Cátedra Roche-UAM: 063203.