Allogeneic hematopoietic stem cell transplant recipients in Spain: Human leukocyte antigen characteristics and diversity by high‐resolution analysis

Abstract

There are many studies on the polymorphism of the HLA system in healthy donor populations, such as registries of unrelated bone marrow donors. Investigations on the characterization of the HLA complex in hematopoietic stem cell transplant (HSCT) patients, however, are scarce, at least in the Spanish population. This study presents a large‐scale analysis of allelic diversity and HLA distribution at a high‐resolution level in 2886 patients undergoing HSCT in Spanish centres of the “Grupo Español de Trasplante Hematopoyético y Terapia Celular” during a period of 11 years. Allelic diversity analysis identified 67 HLA‐A, 133 HLA‐B, 60 HLA‐C, 63 HLA‐DRB1, 24 HLA‐DQB1 and 27 HLA‐DPB1 different alleles. Rare alleles were detected among which 33 alleles had not been reported in the European catalog of common and well‐documented HLA alleles. Regarding the distribution of five genes‐haplotypes, it was observed that the five most frequent extended haplotypes found in our population were between the most common in other Spanish populations, both in patients and in healthy subjects. However, some particular haplotypes were also detected. Bilocus associations HLA‐C ~ B and ‐DRB1 ~ DQB1 were analyzed in order to predict the probability of finding 10/10 matched donors in registries. We found HLA‐B alleles showing a great diversity of combinations with HLA‐C alleles and unusual associations involving a negative predicting factor. In the field of adoptive therapies, our work supports the necessity to expand further research of TCR‐engineered cells, adoptive transfer of virus‐specific T‐cells and vaccines to target HLA alleles other than A*02:01. HLA alleles such as A*01:01, A*03:01, A*24:02, B*44:03, B*07:02 or B*51:01, might be considered new targets due to its high frequency in our population.

An intermediate‐sized donor registry experience: HLA barriers in matching procedures

“…An analysis of patients with rare HLA alleles (frequency <0.1) or HLA alleles which were not observed in our unpublished population data ( N = 10,000 from CBMDR), such as the HLA‐B*15:35, B*51:08, DRB1*11:15 , or DQB1*02:81 alleles, showed that those alleles which were part of a conserved HLA‐A~B~C~DRB1 haplotype were not the cause of mismatches 36,37 . It is in concordance with the statement from a review article by Tiercy, who mentioned that the presence of a rare HLA allele on an extended haplotype might not automatically mean that a 10/10 MUD will not be found 6 …”

Numerical Analysis of the Diversity of Keyboard Instrument Playing Fingerings

“…As shown in Figure 4, the experimental comparison between the Comb-RichModel steganographic analysis model based on diversity features and other steganographic analysis algorithms, it can be seen that filtering is replaced and SPAM features are added. Compared with numerical analysis, the detection accuracy of the Comb-RichModel with diversified features has been improved to some extent, and its detection performance has improved stably from low embedding rate to high embedding rate [22][23]. Mathematical analysis is a steganographic analysis method with diverse features and high dimension.…”