The effect of HLA-DR on susceptibility to rheumatoid arthritis is influenced by the associated lymphotoxin α-tumor necrosis factor haplotype

Objective. HLA-DRB1, a major genetic determinant of susceptibility to rheumatoid arthritis (RA), is located within 1,000 kb of the gene encoding tumor necrosis factor (TNF). Because certain HLA-DRB1*04 subtypes increase susceptibility to RA, investigation of the role of the TNF gene is complicated by linkage disequilibrium (LD) between TNF and DRB1 alleles. By adequately controlling for this LD, we aimed to investigate the presence of additional major histocompatibility complex (MHC) susceptibility genes. Methods. We identified 274 HLA-DRB1*04-positive cases of RA and 271 HLA-DRB1*04-positive population controls. Each subject was typed for 6 single-nucleotide polymorphisms within a 4.5-kb region encompassing TNF and lymphotoxin a (LTA). LTA-TNF haplotypes in these unrelated individuals were determined using a combination of family data and the PHASE software program. Results. Significant differences in LTA-TNF haplotype frequencies were observed between different subtypes of HLA-DRB1*04. The LTA-TNF haplotypes observed were very restricted, with only 4 haplotypes constituting 81% of all haplotypes present. Among individuals carrying DRB1*0401, the LTA-TNF 2 haplotype was significantly underrepresented in cases compared with controls (odds ratio 0.5 [95% confidence interval 0.3-0.8], P = 0.007), while in those with DRB1*0404, the opposite effect was observed (P = 0.007). Conclusion. These findings suggest that the MHC contains genetic elements outside the LTA-TNF region that modify the effect of HLA-DRB1 on susceptibility to RA.

Localization of type 1 diabetes susceptibility to the MHC class I genes HLA-B and HLA-A

The major histocompatibility complex (MHC) on chromosome 6 is associated with susceptibility to more common diseases than any other region of the human genome, including almost all disorders classified as autoimmune. In type 1 diabetes the major genetic susceptibility determinants have been mapped to the MHC class II genes HLA-DQB1 and HLA-DRB1 (refs 1–3), but these genes cannot completely explain the association between type 1 diabetes and the MHC region4, 5, 6, 7, 8, 9, 10, 11. Owing to the region's extreme gene density, the multiplicity of disease-associated alleles, strong associations between alleles, limited genotyping capability, and inadequate statistical approaches and sample sizes, which, and how many, loci within the MHC determine susceptibility remains unclear. Here, in several large type 1 diabetes data sets, we analyse a combined total of 1,729 polymorphisms, and apply statistical methods—recursive partitioning and regression...

A novel human leucocyte antigen-DRB1 genotyping method based on multiplex primer extension reactions

We have developed and validated a semi-automated fluorescent method of genotyping human leucocyte antigen (HLA)-DRB1 alleles, HLA-DRB1*01-16, by multiplex primer extension reactions. This method is based on the extension of a primer that anneals immediately adjacent to the single-nucleotide polymorphism with fluorescent dideoxynucleotide triphosphates (minisequencing), followed by analysis on an ABI Prism 3700 capillary electrophoresis instrument. The validity of the method was confirmed by genotyping 261 individuals using both this method and polymerase chain reaction with sequence-specific primer (PCR-SSP) or sequencing and by demonstrating Mendelian inheritance of HLA-DRB1 alleles in families. Our method provides a rapid means of performing high-throughput HLA-DRB1 genotyping using only two PCR reactions followed by four multiplex primer extension reactions and PCR-SSP for some allele groups. In this article, we describe the method and discuss its advantages and limitations.

Non-inherited maternal HLA alleles are associated with rheumatoid arthritis

Background. Rheumatoid arthritis (RA) is strongly associated with a series of HLA-DRB1 alleles that encode a conserved sequence of amino acids (70Q/R K/R R A A74) in the DRβ1 chain, known as the shared epitope (SE). However 30% of patients are negative for DRB1*04 and 15% are SE-negative. Exposure to these alleles as non-inherited maternal antigens (NIMA) might explain this discrepancy. We undertook a family study to investigate the role of NIMA in RA. Methods. One hundred families, including the RA proband and both parents, were recruited. HLA-DRB1 genotyping was performed using an allele-specific polymerase chain reaction by standard methods. The frequencies of NIMA and non-inherited paternal antigens (NIPA) were compared using contingency tables and a two-tailed P test. We then reviewed four previously published studies of NIMA in RA and conducted an analysis of the combined data Results. We identified 36 families in which the proband was DRB1*04-negative and 13 in which the proband lacked the SE. There was an excess of DRB1*04 and SE NIMA (P=0.05) compared with NIPA. Combined analysis with previous studies showed that 53/231 mothers (23%) versus 25/205 fathers (12%) had a non-inherited DRB1*04 (P=0.003) and 30/99 mothers versus 18/101 fathers had a non-inherited SE allele (P=0.03). Conclusion. A role for HLA NIMA in RA is suggested by these results.

HLA-DR/DQ haplotype in rheumatoid arthritis: Novel allelic associations in UK Caucasians

Objective. To elucidate the relative importance of the HLA-DR and HLA-DQ loci in conferring genetic predisposition to rheumatoid arthritis (RA). Methods. HLA-DRB1 and HLA-DQB1 alleles were typed in a set of 685 patients with RA using sequence-specific polymerase chain reaction. Allele and phenotype frequencies were compared with those in 2 large sets of historical, ethnically matched healthy controls, using the relative predispositional effect method. Results. Positive association was confirmed with the shared epitope positive HLA-DRB1 alleles associated with RA in Caucasians. A significant susceptibility effect was observed with HLA-DRB1*09, described in other ethnically diverse populations but not in Caucasians. A significant underrepresentation of the HLA-DRB1*0103 variant was noted among the RA cases, supporting the proposed protective role of the DERAA motif at residues 70-74 of the DRβ molecule. No HLA-DRB1 independent association of the HLA-DQB1 alleles, implicated in predisposing to RA, was evident. Conclusion. These data corroborate the shared epitope hypothesis of susceptibility to RA and provide strong evidence for the DRB1 locus as the primary RA susceptibility factor in the HLA region.

人类白细胞抗原-DRB1与胃腺癌及其临床特征和幽门螺杆菌感染的相关性

目的　探讨人类白细胞抗原 (HLA) DRB1等位基因与胃腺癌及其临床特征和幽门螺杆菌(Hp)感染的关联性。方法　运用序列特异性引物聚合酶链反应和等位基因序列分析技术 ,检测无亲缘关系湖北省汉族健康人 136例、胃癌组 6 3例的HLA DRB1基因。内镜活检、Giemsa染色和 (或 )外周血ELISA检查胃黏膜Hp感染情况。SAS软件数据处理。 结果　HLA DRB10 90 1、12等位基因均与湖北省汉族人胃腺癌呈正相关 ;HLA DRB115等位基因则呈负相关。携带及非携带上述各等位基因患者 ,分

人类白细胞抗原DRB1和DQB1等位基因多态性与大肠癌的关联性

目的　探讨人类白细胞抗原HLA DRB1, DQB1等位基因与大肠癌遗传关联性。方法　运用序列特异性引物聚合酶链反应 ,结合等位基因序列分析 ,检测无亲缘关系的湖北籍汉族健康人136名、大肠癌组 5 4例患者的HLA DRB1、 DQB1基因。结果　大肠癌患者与正常人比较 ,HLA DRB1 0 90 1等位基因分布频率明显增高 (0 2 315、0 1397,P =0 0 33) ;而 DRB1 0 80X等位基因频率明显降低 (0 0 0 93、0 0 80 9,P =0 0 0 71)。两组间HLA

Repertoire of HLA-DR1-restricted CD4 T cell responses to capsular Caf1 antigen of Y. pestis HLA-transgenic mice

Yersinia pestis is the causative agent of plague, a rapidly fatal infectious disease that has not been eradicated worldwide. The capsular Caf1 protein of Y. pestis is a protective antigen under development as a recombinant vaccine. However, little is known about the specificity of human T cell responses for Caf1. We characterized CD4 T cell epitopes of Caf1 in 'humanized'-HLA-DR1 transgenic mice lacking endogenous MHC class II molecules. Mice were immunized with Caf1 or each of a complete set of overlapping synthetic peptides, and CD4 T cell immunity was measured with respect to proliferative and IFNgamma T cell responses and recognition by a panel of T cell hybridomas, as well as direct determination of binding affinities of Caf1 peptides to purified HLA-DR molecules. Although a number of DR1-restricted epitopes were identified following Caf1 immunization, the response was biased towards a single immunodominant epitope near the C-terminus of Caf1. In addition, potential promiscuous epitopes, including the immunodominant epitope, were identified by their ability to bind multiple common HLA alleles, with implications for the generation of multivalent vaccines against plague for use in humans.

Genotipificación de HLA-B en pacientes colombianos afectados por el síndrome Stevens-Johnson y la Necrólisis Epidérmica Tóxica

Las reacciones alérgicas a medicamentos cutáneas severas (RAM) como el Síndrome Stevens Johnson (SJS) y la Necrólisis Epidérmica Tóxica (NET),caracterizadas por exantema, erosión de la piel y las membranas mucosas, flictenas, desprendimiento de la piel secundario a la muerte de queratinocitos y compromiso ocular. Son infrecuentes en la población pero con elevada morbi-mortalidad, se presentan luego de la administración de diferentes fármacos. En Asia se ha asociado el alelo HLA-B*15:02 como marcador genético para SJS. En Colombia no hay datos de la incidencia de estas RAM, ni de la relación con medicamentos específicos o potenciales y tampoco estudios de aproximación genómica de genes de susceptibilidad.

Diversidade genética do sistema HLA em Portugal, Cabo Verde e Guiné-Bissau

O polimorfismo dos genes HLA-A, HLA-B e HLA-DRB1 foi estudado em três populações Portuguesas (Portugal continental, Madeira e Açores) e em duas Africanas (Guiné-Bissau e Cabo Verde). Os dados em alta resolução, obtidos por sequenciação (SBT), foram comparados com a caracterização efectuada pelo método SSOP revelando 4,6% de incongruências entre os resultados destes dois métodos. Os alelos mais frequentes em cada um dos loci foram: HLA-A*0201 em todas as populações (13,5-26%); HLA-B*5101 em Portugal continental (12%, o mesmo para o B*440301), Madeira (9,7%) e Açores (9,8%) e B*350101 na Guiné-Bissau (14,4%) e Cabo Verde (13,2%); HLADRB1*0701 em Portugal continental (15%), Madeira (15,7%) e Açores (18,3%), DRB1*1304 na Guiné-Bissau (19,6%) e DRB1*110101 em Cabo Verde (10,1%). Os haplotipos 3-loci mais predominantes em cada população foram: A*020101-B*440301-DRB1*070101 em Portugal continental (3,1%), A*020101-B*510101- DRB1*130101 na Madeira (2,7%), A*2902-B*4403-DRB1*0701 nos Açores (2,4%), A*2301-B*1503-DRB1*110101 na Guiné-Bissau (4,6%) e A*3002-B*350101-DRB1*1001 em Cabo Verde (2,8%). O presente trabalho revela que a população continental Portuguesa tem sido influenciada geneticamente por Europeus e Norte Africanos devido a várias imigrações históricas. O Norte de Portugal parece concentrar, provavelmente devido à pressão da expansão Árabe, um antigo pool genético originado pela influência milenar de Europeus e Norte Africanos. Os dados obtidos nos genes do sistema HLA corroboram as fontes históricas que confirmam que o povoamento dos Açores teve o contributo de outros Europeus, essencialmente Flamengos, para além dos Portugueses. As frequências alélicas e haplotípicas neste arquipélago não apresentam uma distribuição homogénea entre as ilhas do grupo Oriental e Central. O grupo Central revela uma influência clara daEuropa Central e uma muito menor afinidade a Portugal continental. As frequências alélicas e haplotípicas mostram que a ilha da Madeira foi povoada por Europeus, a maioria Portugueses, mas também por sub-Saharianos devido ao comércio de escravos. Cabo Verde não é uma população tipicamente sub-Sahariana pois revela uma importante influência genética Europeia, para além da base genética Africana. A análise dos haplotipos e dendrogramas mostram uma influência genética Caucasiana no actual pool genético Cabo-Verdiano. Os dendrogramas e a análise das coordenadas principais mostram que os Guineenses são mais semelhantes aos Norte Africanos do que qualquer outra população sub-Sahariana já estudada ao nível do sistema HLA, provavelmente devido a contactos históricos com outros povos, nomeadamente Árabes do Este Africano e Berberes.

Avaliação da expressão das moléculas HLA de classe I não clássicas HLA-G E HLA-E em espécimes gástricas de pacientes acometidos com a bactéria Helicobacter Pylori

The expression of human leukocyte antigen G (HLA-G) and human leukocyte antigen E (HLA-E) in physiological and pathological processes remains unknown, it is believed that these molecules play a fundamental role in the establishment and maintenance of immune tolerance by inhibiting the functions of immunocompetent cells. In literature we found no published study involving the bacterium Helicobacter pylori (H. pylori) with expression of HLA-G and HLA-E. The objective this study is investigated the expression of this protein in gastric biopsies of patients with the bacterium H. pylori. Sixty-four biopsies of the patients with diagnosis of infection by H. pylori were evaluated to expression of HLA-G and HLA-E. The samples were stratified according to the presence of carcinoma or peptic ulcers. Patients without H. pylori were used to control. To investigate the expression of this protein were used immunohistochemistry technique with monoclonal antibody anti-HLA-G and anti-HLA-E. Other criteria such as analysis of the inflammatory infiltrate (hematoxylin-eosin) and identification of H. pylori (Giemsa) were analyzed. We detected HLA-G and HLA-E molecules in the most samples containing ulcer and gastric carcinoma. In negative control group was not detected the presence of HLA-G and HLA-E. The presence of H. pylori seems modulate the expression of HLA-G and HLA-E, favoring the evolution of infection, giving different degrees of gastric lesion in epithelium of these patients

HLA-DR in Brazilian patients with polyarteritis nodosa (PAN) and microscopic polyangiitis (MPA)

The aim of this study was to evaluate the frequency and clinical associations of HLA-DR alleles in Brazilian Caucasian patients with polyarteritis nodosa (PAN) or microscopic polyangiitis (MPA). We evaluated 29 Caucasian patients with vasculitis classified as PAN or MPA according to the American College of Rheumatology (ACR) 1990 Criteria, Chapel Hill Consensus Conference (CHCC) nomenclature for vasculitis and EULAR recommendations for conducting clinical studies in systemic vasculitis. HLA-DR alleles were typed using polymerase chain reaction-amplified DNA, hybridized with sequence-specific low resolution primers. DNA obtained from 59 Caucasian healthy blood donors were used as control. In order to evaluate if a specific HLA may have influence on the clinical profile of those diseases, we also divided the patients according to Birmingham vasculitis score (BVAS) and Five-Factors Score (FFS) at the time of diagnosis. Increased frequency of HLA-DRB1*16 (p = 0.023) and DRB4*01 (p = 0.048) was found in patients with higher disease activity at the time of diagnosis (BVAS >= 22). Patients with less severe disease (FFS = 0) had a higher frequency of HLA-DRB1*03 (p = 0.011). Patients with gastrointestinal tract involvement had significantly increased frequency of HLA-DRB1*11 or B1*12 (p = 0.046), B1*13 (p = 0.021) and B3 (p = 0.008). In contrast, patients with renal disease, had higher frequency of DRB1*15 or DRB1*16 (p = 0.035) and B5 (p = 0.035). In the subgroup of patients with MPA, increased frequency of HLA-DRB1*15 was found in patients with BVAS >= 22 (p = 0.038) and FFS >= 1 (p = 0.039) suggesting that this allele is associated with more aggressive disease. Antineutrophil cytoplasmic antibodies (ANCA) negative MPA patients had significantly increased frequency of HLA-DRB1*11 or DRB1*12 when compared to ANCA positive patients (p = 0.023). Our results suggest that HLA-DR alleles may influence PAN and MPA clinical expression and outcome and that in MPA they participate in the mechanisms involved in the development to ANCA.

Influence of HLA-DRB-1 alleles on the production of antibody against CSP, MSP-1, AMA-1, and DBP in Brazilian individuals naturally infected with Plasmodium vivax

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Worldwide HLA-E nucleotide and haplotype variability reveals a conserved gene for coding and 3 ' untranslated regions

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo da variabilidade da região codificadora e 3'não traduzida do gene HLA-F no Brasil

Pós-graduação em Patologia - FMB