Next generation sequencing with a semi-conductor technology (Ion Torrent PGM™) for HLA typing: overall workflow performance and debate.

Current high resolution HLA typing technologies produce ambiguous results, and it is often necessary to perform additionnal tests to resolve these ambiguities. Next generation sequencing is a promising technology, which can overcome this problem. It is going to usher a new strategy to determine HLA compatibility between donor and recipient. It can lead to non ambiguous results by analysing the full amplified sequence of HLA genes and by eliminating heterozygote phase ambiguities. Instead, as many new techniques, we can face several problems, such as analysis difficulties because of incomplete HLA sequences in the database or errors related to the sequencing instrumentation. Moreover, the clinical relevance of analysing non coding regions of HLA genes is not well understood, but raise questions about the interest of getting HLA full sequence to understand drugs side effects or pathogenesis of infectious or auto-immune diseases. Our objective in this article is to present a commercial workflow for HLA typing by NGS, on Ion Torrent PGM™ sequencer, and to focus attention about pitfalls encountered during the analysis.

[Pitfalls in interpreting anti-HLA antibodies by Luminex technology]. / Pièges de l'interprétation des anticorps anti-HLA par technologie Luminex.

The Luminex technology has become an important tool for HLA antibody screening and identification. This is the most sensitive technology to detect HLA antibodies for transplant patients and patients on awaiting list, and it has ushered a new strategy to determine HLA compatibility between donor and recipient. Moreover, the clinical relevance of all detected anti-HLA antibodies is not well understood, because this technique was shown to be prone to many artefacts or interferences, leading to a complicated interpretation for biologists and clinicians. Our objective in this article is to provide a careful consideration about this solid phase assay, and to focus attention on raised questions about technical performance and interpretation of the results. We should keep in mind that our results could change the clinical management of sensitized patients, their aptitude to receive a graft, and their follow-up.