A novel genotyping approach to improve transfusion support for patients with HLA and/or HPA alloantibodies

Davey, Susan Rosemary

Abstract

Patients who require platelet transfusion support but have become sensitised to Human Leucocyte Antigens (HLA) or Human Platelet Antigens (HPA) require suitably matched or selected products to avoid adverse transfusion reactions resulting from antibodies reacting with the transfused product. Provision of compatible products for these patients is often challenging, and requires significant resources from the blood service. This study set out to develop and implement next generation sequencing (NGS) technology to enhance the HLA and HPA definition of both platelet donors and recipients.
An NGS based method was designed and developed for high throughput, allele level HLA class I genotyping and used to evaluate the impact of NGS technology on the selection of platelet donors using HLA epitope matching (HEM). In addition, an alternative NGS approach was designed to simultaneously sequence the six genes that code for glycoproteins expressing HPA in order to define all known HPA systems in both donor and patient samples.
Allele level HLA-A, -B and –C genotypes were generated for 519 platelet donors by NGS. A critical evaluation of algorithms used to predict alleles from low to medium resolution HLA types demonstrated that NGS was more accurate when determining HLA epitopes for the selection of platelets by HEM. The HLA genotyping data obtained was used to establish previously undefined HLA allele and haplotype frequencies at third field resolution in the English platelet donor population. This thesis also includes the first reported NGS based method for the simultaneous genotyping of HPA-1 to HPA-29, with the additional capability of novel HPA detection.
NGS has been shown to significantly improve the definition of both HLA and HPA genetic systems and will provide a number of future benefits for laboratories and the patients they support, including provision of well matched transfusion products, the detection of rare or novel polymorphisms and increased knowledge of HLA and HPA frequencies.

• Thesis Type: Thesis
• Publicly Available Date: Jun 7, 2019
• Keywords: Next Generation Sequencing; HLA; HPA; Genotyping
• Public URL: https://uwe-repository.worktribe.com/output/864032
• Award Date: Jul 28, 2018