Next Generation Sequencing of human platelet antigens for routine clinical investigations and donor screening: systematic review and meta analysis

Human platelet antigen genotyping is performed in a number of clinical scenarios, including characterization of immune-mediated thrombocytopenia and provision of HPA-matched platelets. Current gold-standard methods for HPA genotyping utilize single nucleotide variant (SNV) based approaches. This review aims to ascertain if next generation sequencing (NGS) has reasonable grounds to replace SNV-based genotyping for HPA systems. A systematic review was conducted following a comprehensive literature search in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. Studies were subjected to screening based on a defined set of inclusion/exclusion criteria. Study quality, characteristics and results were extracted and a meta-analysis was performed to assess the concordance of HPA genotyping results between NGS and the SNV-based comparators for HPA-1,-2,-3,-4,-5,-15. In total, 3374 potentially eligible articles were identified, only 6 of which were included in the meta-analysis. The pooled proportion agreement for the overall concordance of the 6 included studies was shown to be 0.998, 95%CI [0.995, 0.999], P<0.001. The discrepancies between HPA genotypes obtained the two platforms were due to allele dropout in real-time PCR, thus discordant results were in favor of NGS over SNV-based comparators. Currently available platforms for NGS are not without their limitations, including high upfront instrument costs, data storage, variant calling and availability of appropriately trained staff. Although the findings of this systematic review show substantial evidence for the use of NGS over SNV-based methods for HPA genotyping, these practical limitations present a significant obstacle for widespread implementation of this technology.