In humans, a group of genes encoding HLA, the equivalent of major histocompatibility complex (MHC) in other species, controls the immune responses. HLA aids in distinguishing between self and non-self, and involved in the regulation of innate and adaptive immune response.
HLA typing is a common procedure for assessing compatibility between donor and recipient before organ transplantation. It is also used to identify variants associated with susceptibility of developing genetic immunological diseases.
Considering that the HLA region is the most polymorphic region in the human genome,4 its accurate characterization is critical. Historically HLA typing has been carried out at the phenotypic level, by serological toxicity method using a protease.5 Rapid results is a major advantage of these methods. However, allele-specific information that is critical for HLA typing is not attained with phenotypic tests. Advances in molecular techniques now have enabled allele-level genotypic characterization. NGS has been adopted increasingly as a routine method for HLA typing in transplantation, especially for hematopoietic cell transplantation and solid organ transplantations, where allele-level resolution is critical.4 RNA sequencing (RNA-Seq) is particularly valuable as it provides accurate HLA typing, high throughput and relative HLA gene expression information, which are all important for the outcome of transplantation.4
HLA sequencing using NGS has contributed significantly in immunogenetics, and is especially advantageous in avoiding ambiguous typing results.
Roche provides superior NGS sample preparation reagents to address sample preparation-related issues in HLA typing and other immunogenetics research applications.