Blog

Eurostam final meeting and epitope workshop

The last meeting of EUROSTAM (A Europe-wide strategy to enhance transplantation of highly sensitized patients on basis of Acceptable HLA mismatches, http://eurostam.eu/) took place in Leiden from 18th to 20th of November 2015. It included a workshop on the current status of the definition of HLA epitopes and their clinical relevance.

The Pheno Search utility developed in Geneva as part of this project was presented at the Regentenkamer (see picture below). This tool allow to output HLA phenotypes frequencies in different European populations (including complex search expressions).

Eurostam_Leiden

HLA supertype variation across populations

The HLA-A and B supertype variation in worldwide populations was investigated in a recently published study by Francisco et al. (2015). Some functional differences between HLA-A and HLA-B were uncovered.

To learn more about these results : http://link.springer.com/article/10.1007/s00251-015-0875-9

Reference:
HLA supertype variation across populations: new insights into the role of natural selection in the evolution of HLA-A and HLA-B polymorphisms
Rodrigo dos Santos Francisco , Stéphane Buhler, José Manuel Nunes, Bárbara Domingues Bitarello, Gustavo Starvaggi França, Diogo Meyer, Alicia Sanchez-Mazas
Immunogenetics.

International summer school on immunogenetics

The HLA-net bioinformatics platform was recently presented in a talk given during the 11th International Summer School on Immunogenetics (15-18 October, 2014). The school was organized by ASHI (American Society for Histocompatibility and Immunogenetics) with support from EFI (European Federation for Immunogenetics) and APHIA (Asia-Pacific Histocompatibility and Immunogenetics Association) in Boulder at the foothills of the Rocky Mountains.

Close to 50 participants from all over the world attended the meeting as shown on this souvenir pic.

ISS 2014_Boulder

Population Genetics at EFI in Stockholm

A report of the Population Genetics/Anthropology session of the latest EFI congress in Stockholm has been published in the EFI newsletter of this month.

The collaborative HLA-net study on a new HLA map of Europe was among the abstracts presented during this session, among many other very interesting talks. Discover more about this session and the rest of the congress in the newsletter.

Including some social event pics like the one below at the Welcome reception in the beautiful and golden Stockholm City Hall.

EFI_Stockholm

DisambiGuation of common HLA ambiGuities

15 laboratories of the HLA-NET BM0803 Action participated in this comprehensive study aimed at resolving three of the most common ambiguous group of alleles (HLA-B*44:02:01G, -DRB1*14:01:01G and -DQB1*03:01:01G) encountered during HLA typing. Almost 5100 individuals from 12 European countries were analyzed, providing the most detailed record to date on these ambiguities (relative ratios of alleles, linkage disequilibrium with other HLA loci, …).

Because these ambiguities are due to polymorphisms located outside of the exons coding for the peptide binding region, they may not be recognized by alloreactive T-cells. However, because of strong linkage disequilibrium (LD), mismatches for these ambiguous groups are associated to DRB3-, and C-mismatches. These results are thus very informative for algorithms searching unrelated hematopoietic stem cell donors. Furthermore, the introduction of human leukocyte antigen (HLA)-typing strategies that allow resolving exon 4 (for class I) and exon 3 (for class II) polymorphisms can be expected to contribute significantly to population genetics studies.

Read the article on Tissue Antigens website

Reference
Vidan-Jeras, B., S. Buhler, V. Dubois, Z. Grubic, M. Ivanova, T. Jaatinen, D. Ligeiro, et al. “Resolution of HLA-B*44:02:01G, -DRB1*14:01:01G and -DQB1*03:01:01G Reveals a High Allelic Variability among 12 European Populations.” Tissue Antigens, September 1, 2014. doi:10.1111/tan.12422.

Summertime

The 28th EFI conference seems now faraway, yet for us summertime still not here.

The days are getting already getting shorter and, before they get too short, we finally upload two photos from the session were HLA-net became public.

IMG_5814

The session started right in time, after lunch, and lasted long, but participants were so brave that they resisted to sleep.

open meeting photo

Or so we believe.

With this souvenir we thank to all participants, present or not. If summer is not too bad, a few new gadgets will be on the site by the end of August. Until then; have a nice summer.

HLA Imputation: the verdict is not guilty.

It is my opinion that 28th EFI conference poster P225
EVALUATION OF IMPUTATION METHODS FOR CLASSICAL HLA-DRB1 USING A
FINNISH DATASET
would have deserved selection for oral presentation to give it a broader audience, and pass an important message.

Anyway, this Finnish study shows, by using data obtained independently of the imputation study, that only 25% of alleles are correctly imputed. In other words; imputation is disproved.

Now it is time to enjoy Stockholm.

A Skål to the organisers!