HLA-B44 subtyping in a Spanish population: further evidence of Caucasian population diversity

HLA-B44 is the most frequent HLA-B allele in Caucasian populations. Several B44 subtypes, B*4402-B*4406, have been identified in individuals with this ethnic origin. Mismatches among B44 subtypes have been described as major targets for allogeneic responses in bone marrow transplantation. We have developed a PCR-SSO method, based on a B12- specific DNA amplification of exon 2 through exon 3 and subsequent non radioactive hybridization with eight probes, which allow us to discriminate all B12 homozygous combinations. We applied this method to determine the frequency of B44 subtypes in a Spanish population, as well as their HLA-A.-C.-DRB1,-DRB3/DRB4/DRB5.-DQA1 and -DQB1 associated haplotypes. A total of 141 healthy unrelated Spanish individuals and 31 B44-bearing haplotypes were investigated. Four B44 alleles were identified, B*4402 (33%), B*4403 (66%), B*4404 (0.7%), and B*4405 (0.7%). Haplotype analysis showed a clear differentiated distribution pattern for the two major B44 subtypes. B*4402 is associated with Cw5 (11/13) and A2 antigens (10/13). In contrast, B*4403 is mainly found together with DRB1*0701 (14/16). An inverted B*4402/B*4403 frequency in comparison with other European and North American Caucasian populations, revealed the existence of an extended haplotype diversity between populations of the same ethnic origin. Apart from anthropological studies, high resolution typing for HLA class I antigens presenting molecular polymorphism will be of great relevance in unrelated bone marrow transplantation.     

The novel HLA-Cw*1802 allele is associated with B*5703 in the Bubi population from Equatorial Guinea

The HLA-Cw*1801 specificity, a Cw7/Cw4 hybrid allele, has recently been described in association with B*8101 (formerly B"DT"). In this study, the new Cw*1802 variant, differing from Cw*1801 at exon 5. is found associated with B*5703 in Bubi individuals from Equatorial Guinea. Confirmatory complete coding regions of B*5703 and B*3910 are also reported.     

Identification of a novel allele HLA-B*7805 in a Japanese female

A new HLA-B*78 allele, B*7805, was identified in a healthy Japanese female. The results of her serological HLA class I typing showed an unusual Bw4/Bw6 pattern with strongly positive reactivity to anti-Bw6, i.e. A24, -, B52, -, Bw4, Bw6. In DNA typing, she was typed as A*24, -, B*52, B*78-like, Cw1202, -, (Bw4, Bw6). Cloning and sequencing of exon 2 and exon 3 of her B locus genes revealed a new allele B*7805. The cloned B*7805 differed from B*78021 by three nucleotide substitutions in exon 2 at position 259 (A to G), 261 (C to G) and 272 (A to C), and contained sequences defining Bw6 motif in the region of codon 77 to 83.     

Seven new HLA-B alleles associated with antigens in the B7 CREG

This paper describes seven novel HLA-B alleles. Five of these new alleles contain polymorphic motifs previously reported in HLA-B alleles, suggesting an origin resultant from a gene conversion mechanism. B*0723 contains a polymorphism previously unreported in class I HLA molecules. B*4105 contains a nucleotide substitution previously unreported in class I HLA molecules, which encodes a protein sequence previously reported only in HLA-C locus alleles.     

Beta 2-microglobulin amyloid deposit in HLA-B27 transgenic rats

Abstract

Beta 2-microglobulin (beta 2-m) amyloid deposition develops serious orthopedic complications in patients with long-term hemodialysis. However, the exact pathogenesis of amyloid deposition in patients with dialysis is unknown. We used transgenic rats with HLA-B27 and beta 2-m to develop an in vivo animal model with beta 2-m amyloid-associated disorders to investigate the mechanism of formation and to report histological findings of beta 2-m amyloid deposition. Transgenic rats were divided into two groups: group 1, no treatment; group 2, arthritis induced by type II collagen. A large number of cells labeled with beta 2-m were observed in the bone marrow and synovium of the knee joint in transgenic rats. In addition, amyloid deposition, identified by Congo red staining, was found only in the knee joints of the transgenic rats with collagen-induced arthritis. Immunostaining with beta 2-m demonstrated the same pattern of tissue distribution as Congo red in serial sections. We hypothesized that elevated serum beta 2-m level-associated local chronic inflammation leads to the development of amyloid deposits and resultant arthropathy.     

参照链介导的构象分析策略在HLA-B位点分型中的临床应用研究

目的建立并稳定HLAB位点的参照链介导的构象分析(RSCA)系统,并鉴定RSCA分型策略的优势。方法提取27例造血干细胞移植患者及63名供者的外周血DNA,采用RSCA进行HLAB位点分型,并与序列特异性引物聚合酶链反应技术(PCRSSP)分型结果进行比较,对于疑难标本采用测序鉴定。结果在90份标本中,87份(96.7%)可明确判定结果,其中有1份标本与PCRSSP结果不一致,经测序鉴定RSCA结果正确;67份(74.4%)可直接指定等位基因型别。此外,1份标本(1.1%)因PCR扩增结果太弱而未能获得RSCA分型结果,2份标本只能确定1条等位基因,经测序发现另1条等位基因为已知等位基因,但RSCA数据库中没有其数据。随机选择20份标本进行RSCA重复性实验,重复率为100%。在PCRSSP方法分型中,约有10%的标本需要重复1～3次方能判定结果。结论RSCA具有灵敏、特异、分辨率高、重复性好、可发现变异基因及新的等位基因、大规模和低成本等优点,适用于大规模的无关移植供、受者的选择。     

HLA-B27基因亚型检测与强直性脊柱炎相关性研究

目的探讨HLA-B27基因亚型与强直性脊柱炎的相关性。方法采用酵素免疫法检测HLA-B27，并进一步采用聚合酶链反应序列特异性引物法进行HLA-B27基因亚型分型。结果强直性脊柱炎HLA-B27检出率为95％，显著高于正常对照组，基因分型B2705分布最广（59.3％），其次是B2704（38．9％）。结论HLA-B27与AS具有明显的相关性，检测B2705和B2704亚型对于AS的辅助诊断具有重要意义。     

Genotyping for HLA-A, B and C alleles in Japanese patients with pemphigus: prevalence of Asian alleles of the HLA-B15 family

BACKGROUND: There have been only limited reports on major histocompatibility complex class I antigens in pemphigus. OBJECTIVES: To characterize HLA-A, B and C class I alleles by genotyping in Japanese patients with pemphigus, and to analyse the possible association of class I alleles with disease susceptibility within a relatively homogeneous ethnic population. METHODS: Alleles of HLA-A, B and C, and DRB1 and DQB1 loci were fully determined in 51 Japanese patients with pemphigus. RESULTS: Asian alleles of the HLA-B15 family, including the allele B*1507, which was significantly increased in comparison with normal controls, were prevalent in patients with pemphigus vulgaris (PV). The prevalence of B*15 alleles in patients with PV was not due to linkage disequilibrium with HLA-DR4 or DR14 alleles, which have been shown to confer strong susceptibility to PV across racial barriers. In contrast to the unique distribution of the HLA-B alleles, HLA-A and C alleles were unremarkable in patients with PV when compared with normal control subjects. CONCLUSIONS: These results suggest that there may be differences in the ethnic concentrations of different HLA-B alleles in patients with PV.