A complement-mediated rat xenotransfusion model of platelet refractoriness.

Mol Immunol

Department of Pediatrics, Eastern Virginia Medical School, 700 West Olney Road, Norfolk, VA 23507, USA; Children's Specialty Group, 811 Redgate Avenue, Norfolk, VA 23507, USA; Children's Hospital of The King's Daughters, 601 Children's Lane, Norfolk, VA 23507, USA; Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, 700 West Olney Road, Norfolk, VA 23507-1696, USA. Electronic address:

Published: August 2020

Background: Platelet refractoriness remains a challenging clinical dilemma although significant advancements have been made in identifying human leukocyte antigen (HLA) matched or HLA compatible units. Antiplatelet antibodies are the major risk factor for immune-mediated platelet refractoriness, yet the role of antibody-initiated complement-mediated platelet destruction remains poorly understood.

Study Design And Methods: Human complement-mediated opsonization and killing of platelets was assayed ex vivo using antibody-sensitized human platelets incubated with complement-sufficient human sera. A new animal model of platelet refractoriness utilizing Wistar rats transfused with human platelets is described.

Results: Human platelets sensitized with anti-platelet antibodies were rapidly opsonized with iC3b upon incubation in human sera. This opsonization could be completely blocked with a classical pathway complement inhibitor, PA-dPEG24. Complement activation decreased platelet viability, which was also reversible with complement inhibitor PA-dPEG24. A new rat model of platelet refractoriness was developed that demonstrated some platelet removal from the blood stream was complement mediated.

Conclusions: Complement activation initiated by anti-platelet antibodies leads to complement opsonization and decreased platelet viability. A new rat model of platelet refractoriness was developed that adds a new tool for elucidating the mechanisms of platelet refractoriness.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.molimm.2020.05.008DOI Listing

Publication Analysis

Top Keywords

platelet refractoriness
28
model platelet
16
human platelets
12
platelet
11
human sera
8
anti-platelet antibodies
8
complement inhibitor
8
inhibitor pa-dpeg24
8
complement activation
8
decreased platelet
8

Similar Publications

Background: The objective of this study was to investigate the therapeutic effectiveness and safety profile of Eltrombopag, a thrombopoietin receptor agonist, as prolonged therapy in refractory CTD-ITP patients.

Methods: We conducted a pilot observational study of Eltrombopag in CTD-ITP patients who were unresponsive to or intolerant of conventional medications. Eltrombopag was administered orally at 25-75 mg/qd and adjusted on the basis of tolerance and efficacy until a minimum dosage of 25 mg/qd was reached.

View Article and Find Full Text PDF

To retrospectively analyze the dual plasma molecular adsorption system (DPMAS) treatment technology and the laboratory data before and after treatment in patients with liver failure and refractory hyperbilirubinemia, so as to provide a clinical basis for the prediction and prevention of common related complications. A retrospective study was conducted on 161 cases with liver failure and 68 cases with refractory hyperbilirubinemia who underwent DPMAS treatment in our department from October 2022 to July 2024. The general clinical data characteristics, DPMAS treatment status, DPMAS-related complications, and changes in important laboratory indicators before and after the initial DPMAS treatment in both patient groups were analyzed.

View Article and Find Full Text PDF

Background: Thrombopoietin receptor agonists (TPO-RAs) have demonstrated efficacy in treating clinically significant thrombocytopenia, including chemotherapy-induced thrombocytopenia in adults. However, data regarding their safety and efficacy in pediatric, adolescents, and young adult (AYA) patients with hematologic malignancies are limited.

Methods: We retrospectively identified 15 pediatric and AYA patients aged 25 years or younger with hematologic malignancies treated with a TPO-RA at UCSF Benioff Children's Hospitals between 2015 and 2023.

View Article and Find Full Text PDF

Transfusion of platelet concentrates (PC) can be a life-saving measure in case of severe thrombocytopenia or thrombocytopathy, particularly in bleeding patients. Although acaryote, platelets are involved in several important functions including immunomodulation, but their most important function is in primary and secondary haemostasis. In this German review, apheresis and whole blood derived PC are compared and indications as well as transfusion triggers and dosage of PC are discussed.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!