Human leukocyte antigens (HLA) are encoded by the most polymorphic group of genes in the human genome, and the antigens constitute the major immunologic barrier to platelet transfusion and transplantations. High-resolution HLA typing of patients and donors will allow accurate assessment of their histocompatibility and has become a requirement in the latest FACT standards. How to best accomplish such a highly complex test within a satisfactory turnaround time remains an open question for the transfusion and transplantation community.
Several commercial and investigational workflows based on the second- and third-generation sequencing technologies have been successfully implemented for high-resolution HLA typing. In this session, we will first introduce methods based on the second-generation sequencing platforms, Illumina and Ion Torrent, that perform massive parallel sequencing of clonal libraries prepared from long-range amplicons of target HLA genes. The sequencing chemistry, assay performance, and quality metrics of these methods will be presented. Next, we will transition to two third-generation platforms, developed by Oxford Nanopore Technologies and Pacific Biosciences (PacBio), sequencers that enable single-molecule sequencing to generate long reads of thousands of bases for HLA typing. The opportunities and challenges brought by these third-generation platforms will be contrasted with the second-generation sequencing. We will also share the emerging evidence supporting a role of ultra-high-resolution HLA matching facilitated by the PacBio technology in improving the outcome of hematopoietic stem cell transplantations.
List the differences between the second- and third-generation sequencing technologies.
Compare the pros and cons of these technologies for high-resolution HLA typing.
Employ the knowledge to identify the appropriate method for their transfusion and transplantation services.