Platelets retain function and can be stored following disruption of human leucocyte antigens

April M Davis; Renée Rawson; Gail Pahn; James Daly; Denese C Marks

doi:10.1111/vox.13634

Platelets retain function and can be stored following disruption of human leucocyte antigens

Vox Sang. 2024 Apr 10. doi: 10.1111/vox.13634. Online ahead of print.

Authors

April M Davis¹, Renée Rawson¹, Gail Pahn², James Daly³, Denese C Marks^{1

4}

Affiliations

¹ Australian Red Cross Lifeblood, Research and Development, Sydney, New South Wales, Australia.
² Australian Red Cross Lifeblood, Transplantation and Immunogenetics, Brisbane, Queensland, Australia.
³ Australian Red Cross Lifeblood, Pathology and Clinical Governance, Brisbane, Queensland, Australia.
⁴ Sydney Medical School, The University of Sydney, Camperdown, New South Wales, Australia.

PMID: 38596985
DOI: 10.1111/vox.13634

Abstract

Background and objectives: Antibodies to human leucocyte antigen (HLA) Class-I antigens can lead to refractoriness to platelet transfusion. Although this can be overcome by transfusion of HLA-compatible platelets, they are not always available. Disruption of HLA antigens on platelets by acid treatment may be a suitable alternative when no other components are available. The aim of this study was to assess the effect of HLA disruption and subsequent storage of platelet components.

Materials and methods: Platelet components were treated with 0.9% saline or citric acid solution (pH 3.0), and then stored until expiry (Day 7). HLA and platelet glycoprotein expression, platelet viability, activation and sialylation were measured by flow cytometry. Release of soluble factors was measured by ELISA and metabolism by biochemistry analyser. Reactivity to patient anti-sera containing anti-HLA antibodies was measured using platelet immunofluorescence tests (PIFTs) and monoclonal antibody immobilization of platelet antigen (MAIPA) assays. Platelet function was measured using aggregometry and thromboelastography (TEG).

Results: Acid treatment reduced detection of HLA Class-I on platelets by 75%, with significant reductions in reactivity to patient anti-sera. Acid treatment reduced platelet content and viability, increased platelet activation and accelerated metabolism. Glycan cleavage was increased by acid treatment. Treatment reduced platelet activation following agonist stimulation by ADP and TRAP-6, but platelets remained functional, displaying increased aggregation response and reduced time to clot formation by TEG.

Conclusion: Although HLA disruption had some detrimental effects, acid-treated platelets remained functional, retaining their capacity to respond to agonists and form clots, and with further development could be used to support refractory patients.

Keywords: blood components; function; human leucocyte antigen; platelets; quality; refractoriness.

Grants and funding

Australian Governments