Modulation of ultralarge immune complexes in heparin-induced thrombocytopenia

Copyright © 2022 International Society on Thrombosis and Haemostasis. Published by Elsevier Inc. All rights reserved..

BACKGROUND: Heparin-induced thrombocytopenia (HIT) is a serious thrombotic disorder caused by ultralarge immune complexes (ULICs) containing platelet factor 4 (PF4) and heparin that form the HIT antigen, together with a subset of anti-PF4 antibodies. ULICs initiate prothrombotic responses by engaging Fcγ receptors on platelets, neutrophils, and monocytes. Contemporary anti-thrombotic therapy for HIT is neither entirely safe nor entirely successful and acts downstream of ULIC formation and Fcγ receptor-initiated generation of thrombin.

OBJECTIVES: To determine whether HIT antigen and ULIC formation and stability could be modified favorably by inhibiting PF4-heparin interactions with fondaparinux, together with blocking formation of PF4 tetramers using a humanized monoclonal anti-PF4 antibody (hRTO).

METHODS: Results: The combination of fondaparinux and hRTO inhibited HIT antigen formation, promoted antigen dissociation, inhibited ULIC formation, and promoted ULIC disassembly at concentrations below the effective concentration of either alone and blocked Fcγ receptor-dependent induction of factor Xa activity by monocytic THP1 cells and activation of human platelets in whole blood. Combined with hRTO, fondaparinux inhibited HIT antigen and immune complex formation and activation through Fcγ receptors at concentrations at or below those used clinically to inhibit FXa coagulant activity.

CONCLUSIONS: HIT antigen and immune complexes are dynamic and amenable to modulation. Fondaparinux can be converted from an anticoagulant that acts at a downstream amplification step into a rationale, disease-specific intervention that blocks ULIC formation. Interventions that prevent ULIC formation and stability might increase the efficacy, permit use of lower doses, shorten the duration of antithrombotic therapy, and help prevent this serious thrombotic disorder.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:21

Enthalten in:

Journal of thrombosis and haemostasis : JTH - 21(2023), 3 vom: 13. März, Seite 652-666

Sprache:

Englisch

Beteiligte Personen:

Cai, Zheng [VerfasserIn]
Bdeir, Khalil [VerfasserIn]
Yarovoi, Serge V [VerfasserIn]
Rauova, Lubica [VerfasserIn]
Arepally, Gowthami M [VerfasserIn]
Khandelwal, Sanjay [VerfasserIn]
Rollin, Jerome [VerfasserIn]
Gruel, Yves [VerfasserIn]
Zaitsev, Sergei [VerfasserIn]
Poncz, Mortimer [VerfasserIn]
Greene, Mark I [VerfasserIn]
Cines, Douglas B [VerfasserIn]

Links:

Volltext

Themen:

37270-94-3
9005-49-6
Antibodies, Monoclonal, Humanized
Antibody
Anticoagulants
Antigen-Antibody Complex
Antigen-antibody complex
Fondaparinux
Heparin
J177FOW5JL
Journal Article
Platelet Factor 4
Receptors, IgG
Research Support, N.I.H., Extramural
Thrombocytopenia
Thrombosis

Anmerkungen:

Date Completed 08.03.2023

Date Revised 14.03.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.jtha.2022.11.043

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM352067586