RESUMO
The B*14:41N allele was identified in a The National Marrow Donor Program (NMDP) Hispanic donor typed by our Mexican Registry-DONORMO.
Assuntos
Antígeno HLA-B14/genética , Hispânico ou Latino/genética , Sistema de Registros , Doadores não Relacionados , Sequência de Bases , Medula Óssea , Éxons/genética , Humanos , México , Dados de Sequência Molecular , Alinhamento de SequênciaRESUMO
BACKGROUND: Allergies have been described as protective factors against the development of childhood acute leukaemia (AL). Our objective was to investigate the associations between allergy history and the development of AL and acute lymphoblastic leukaemia (ALL) in children with Down syndrome (DS). METHODS: A case-control study was performed in Mexico City. The cases (n=97) were diagnosed at nine public hospitals, and the controls (n=222) were recruited at institutions for children with DS. Odds ratios (OR) were calculated. RESULTS: Asthma was positively associated with AL development (OR=4.18; 95% confidence interval (CI): 1.47-11.87), whereas skin allergies were negatively associated (OR=0.42; 95% CI: 0.20-0.91). CONCLUSION: Our findings suggest that allergies and AL in children with DS share biological and immune mechanisms. To our knowledge, this is the first study reporting associations between allergies and AL in children with DS.
Assuntos
Síndrome de Down/epidemiologia , Hipersensibilidade/epidemiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiologia , Estudos de Casos e Controles , Criança , Feminino , Humanos , Modelos Logísticos , Masculino , México/epidemiologiaRESUMO
The A*29:47 allele was identified in a Mexican Mestizo unrelated bone marrow donor from the state of Hidalgo.
Assuntos
Transplante de Medula Óssea , Antígenos HLA-A/genética , Sequência de Bases , Éxons/genética , Frequência do Gene , Teste de Histocompatibilidade , Humanos , Masculino , México , Pessoa de Meia-Idade , Dados de Sequência Molecular , Mutação/genética , Filogenia , Estabilidade Proteica , Doadores de TecidosRESUMO
Studies of the effect of minor H antigen mismatching on the outcome of renal transplantation are scarce and concern mainly single center studies. The International Histocompatibility and Immunogenetics Workshops (IHIW) provide a collaborative platform to execute crucial large studies. In collaboration with 16 laboratories of the IHIW, the role of 15 autosomal, 10 Y-chromosome encoded minor H antigens and 3 CD31 polymorphisms, was investigated in relation to the incidence of renal graft rejection and graft loss in 444 human leukocyte antigens (HLA)-identical sibling renal transplantations. Recipient and donor DNA samples were genotyped for the minor H antigens HA-1, HA-2, HA-3, HA-8, HB-1, ACC-1, ACC-2, SP110, PANE1, UGT2B17, C19Orf48, LB-ECGF-1, CTSH, LRH-1, LB-ADIR and HY. The correlation between minor H antigen mismatch and the primary outcome graft rejection or graft loss was statistically analyzed. The incidence of rejection was very low and no correlation was observed between one or more minor H antigen mismatch(es) and a rejection episode (n = 36), of which only eight resulted in graft loss. In summary, in our study cohort of 444 renal transplants, mismatching for neither autosomal nor HY minor H antigens correlate with rejection episodes or with graft loss.
Assuntos
Antígenos HLA/imunologia , Teste de Histocompatibilidade , Transplante de Rim/efeitos adversos , Antígenos de Histocompatibilidade Menor/imunologia , Irmãos , Estudos de Coortes , Rejeição de Enxerto/imunologia , HumanosRESUMO
In the last fifteen years, published reports have described KIR gene-content frequency distributions in more than 120 populations worldwide. However, there have been limited studies examining these data in aggregate to detect overall patterns of variation at regional and global levels. Here, we present a summary of the collection of KIR gene-content data for 105 worldwide populations collected as part of the 15th and 16th International Histocompatibility and Immunogenetics Workshops, and preliminary results for data analysis.
Assuntos
Variação Genética , Histocompatibilidade/genética , Receptores KIR/genética , Etnicidade/genética , Frequência do Gene , Genética Populacional , Haplótipos , Humanos , Imunoglobulinas/genética , LigantesRESUMO
This report describes the project to identify the global distribution of extended HLA haplotypes, a component of 16th International HLA and Immunogenetics Workshop (IHIW), and summarizes the initial analyses of data collected. The project aims to investigate extended HLA haplotypes, compare their distribution among different populations, assess their frequency in hematopoietic stem cell unrelated donor registries and initiate an international family studies database and DNA repository to be made publicly available. HLA haplotypes compiled in immunogenetics laboratories during the evaluation of transplant candidates and related potential donors were analysed. Haplotypes were determined using the pedigree analysis tool publicly available from the National Marrow Donor Program (NMDP) website. Nineteen laboratories from 10 countries (11 laboratories from North America, five from Asia, two from Latin America and one from Australia) contributed data on a total of 1719 families comprised of 7474 individuals. We identified 10393 HLA haplotypes, of which 1682 haplotypes included high-resolution typing at HLA-A, B, C, DRB1 and DQB1 loci. We also present haplotypes containing MICA and other HLA loci and haplotypes containing rare alleles seen in these families. The project will be extended through the 17th IHIW, and investigators interested in joining the project may communicate with the first author.
Assuntos
Variação Genética , Antígenos HLA/genética , Haplótipos , Grupos Populacionais/genética , Austrália , Frequência do Gene , Genética Populacional , Genótipo , Antígenos HLA/classificação , Antígenos de Histocompatibilidade Classe I/genética , Humanos , América do NorteRESUMO
A*02:336 was identified in a Mexican Mestizo ALL patient, born in the State of Veracruz.
Assuntos
Alelos , Etnicidade/genética , Antígeno HLA-A2/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras , Sequência de Bases , Pré-Escolar , Éxons/genética , Humanos , Masculino , México/etnologia , Dados de Sequência Molecular , Leucemia-Linfoma Linfoblástico de Células Precursoras/genéticaRESUMO
The killer immunoglobulin-like receptor (KIR) anthropology component of the 15th International Histocompatibility Workshop (IHIWS) sought to explore worldwide population variation in the KIR loci, and to examine the relationship between KIR genes and their human leukocyte antigen (HLA) ligands. Fifteen laboratories submitted KIR genotype and HLA ligand data in 27 populations from six broad ethnic groups. Data were analyzed for correlations between the frequencies of KIR and their known HLA ligands. In addition, allelic typing was performed for KIR2DL2 and 3DL1 in a subset of populations. Strong and significant correlations were observed between KIR2DL2, 2DL3 genotype frequencies and the frequency of their ligand, HLA-C1. In contrast, only weak associations were seen for 3DL1, 3DS1 and the HLA-Bw4 ligand. Although some aspects of the correlations observed here differ from those reported in other populations, these data provide additional evidence of linked evolutionary histories for some KIR and HLA loci. Investigation of allele-level variation for the B haplotype locus KIR 2DL2 showed that two alleles, *001 and *003, predominate in all populations in this study. Much more allelic variation was observed for the A haplotype locus 3DL1, with several alleles observed at moderate frequencies and extensive variation observed between populations.
Assuntos
Evolução Molecular , Variação Genética , Antígenos HLA/genética , Receptores KIR/genética , Loci Gênicos , Genótipo , Antígenos HLA/imunologia , Humanos , Polimorfismo Genético , Receptores KIR/imunologiaRESUMO
BACKGROUND: For a child to develop acute leukaemia (AL), environmental exposure may not be sufficient: interaction with a susceptibility factor to the disease, such as Down syndrome (DS), may also be necessary. We assessed whether breastfeeding and early infection were associated with the risk of developing AL in children with DS. METHODS: Children with DS in Mexico City, and either with or without AL, were the cases (N=57) and controls (N=218), respectively. Population was divided in children with AL and with acute lymphoblastic leukaemia (ALL) and also in children < or = 6 and >6 years old. RESULTS: Breastfeeding and early infections showed moderate (but not significant) association for AL, whereas hospitalisation by infection during the first year of life increased the risk: odds ratios (confidence interval 95%) were 0.84 (0.43-1.61), 1.70 (0.82-3.52); and 3.57 (1.59-8.05), respectively. A similar result was obtained when only ALL was analysed. CONCLUSION: We found that breastfeeding was a protective factor for developing AL and ALL, and during the first year of life, infections requiring hospitalisation were related to a risk for developing the disease in those children with DS >6 years of age. These data do not support the Greaves's hypothesis of early infection being protective for developing ALL.
Assuntos
Aleitamento Materno/efeitos adversos , Síndrome de Down/complicações , Infecções/complicações , Infecções/epidemiologia , Leucemia Mieloide/epidemiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicações , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiologia , Doença Aguda , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , Síndrome de Down/diagnóstico , Síndrome de Down/epidemiologia , Feminino , Humanos , Lactente , Recém-Nascido , Leucemia Mieloide/complicações , Leucemia Mieloide/diagnóstico , Masculino , Razão de Chances , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Análise de Regressão , Inquéritos e QuestionáriosRESUMO
DRB1*1532 allele was identified in a Mexican unrelated marrow donor from the Gulf of Mexico.
Assuntos
Alelos , Cidades , Antígenos HLA-DR/genética , Indígenas Norte-Americanos/genética , Doadores de Tecidos , Pareamento Incorreto de Bases , Sequência de Bases , Células da Medula Óssea/citologia , Códon , DNA/genética , DNA/isolamento & purificação , Éxons , Feminino , Variação Genética , Genótipo , Cadeias HLA-DRB1 , Haplótipos , Teste de Histocompatibilidade/métodos , Humanos , Leucócitos/química , México , Dados de Sequência Molecular , Mutação Puntual , Reação em Cadeia da Polimerase , Padrões de Referência , Análise de Sequência de DNA/métodos , Terminologia como Assunto , Adulto JovemRESUMO
Human leukocyte antigen-B*9550 is a novel allele identified in a Mexican Mestizo bone marrow donor from Veracruz.
Assuntos
Substituição de Aminoácidos/genética , Medula Óssea/imunologia , Antígenos HLA-B/genética , Alelos , Sequência de Bases , Éxons/genética , Humanos , Doadores Vivos , México , Dados de Sequência Molecular , Alinhamento de SequênciaRESUMO
The Mestizos of Oaxaca resulted from the admixture of Zapotecan Natives with Spaniards and Africans. We selected 112 donors from Oaxaca and applied next-generation sequencing to characterize exon and intron variants in complete or extended HLA genes. Some alleles found, are unique to Mexican Natives and most likely will be absent in most major ethnicities, namely: Caucasians, Africans or Asians. Among these are HLA-A*68:03:01, HLA-A*68:05:01, HLA-C*03:04:01:02, HLA-C*15:09, HLA-C*3:05, HLA-C*03:06:01, HLA-B*39:05:01, HLA-B*35:14:01, HLA-B*35:12:01, HLA-B*35:43:01, HLA-B*40:05, HLA-B:40:08, HLA-B*51:02:01, HLA-B*35:24:01 and HLA-B*39:08. HLA-DQA1*05:05:01:05 and some HLA-DRB1 alleles were only present in Amerindians/Mestizos. Three haplotypes are unique to Mexican Natives, five to Middle-Eastern and Sephardi-Jews. We detected a novel HLA-DQA1*04:01:01 exon 4 variant. Any novel allele may have been positively selected to enlarge the peptide-binding repertoire, and some, like HLA-B*39:02:02 and HLA-B*39:05:01 were found with unique haplotype associations, suggesting convergent evolution events and/or allele lineage diversification. The allele frequencies were fairly evenly distributed in most HLA loci with the exception of HLA-DPB1. The application of NGS in Oaxaca is novel and will lead to better use in the clinical setting. It offers deep knowledge on the population structure, origins, migration, and discovery of new alleles and haplotypes that other techniques did not achieve.
Assuntos
Alelos , Etnicidade/genética , Genética Populacional , Antígenos HLA/genética , Adulto , Feminino , Frequência do Gene , Haplótipos , Sequenciamento de Nucleotídeos em Larga Escala , Teste de Histocompatibilidade , Humanos , Masculino , México , Análise de Sequência de DNAAssuntos
Transplante de Medula Óssea , Antígeno HLA-B35/genética , Adulto , Sequência de Bases , Teste de Histocompatibilidade , Humanos , Masculino , México , Dados de Sequência Molecular , Polimorfismo de Nucleotídeo Único , Sistema de Registros , Alinhamento de Sequência , Doadores de Tecidos , Voluntários , Adulto JovemRESUMO
Neurocysticercosis (NC) is caused by the establishment of the metacestode stage of Taenia solium in the human central nervous system. A great heterogeneity in the susceptibility to the infection and to the disease has been reported. While the factors involved in this heterogeneity are not completely understood, clearly different immune-inflammatory profiles have been associated to each condition. This study evaluated the association of cytokine single nucleotide polymorphisms (SNPs) with susceptibility to infection and disease severity in NC patients. Blood samples from 92 NC cases and their parents (trios) were genotyped for SNPs in five cytokines relevant for the immune response: IL4 (-589C/T), IL6 (-174C/G), IFNG (+874T/A), TNF (-238G/A), and IL2 (-330G/T). Specific DNA fragments were amplified by the polymerase chain reaction, using the 5'-nuclease Taqman assay on a 7500 platform, allowing the detection of the polymorphism genotypes. No association between the polymorphisms evaluated neither with susceptibility to infection nor with disease severity was found, although previous studies reported variations in the levels of these cytokines among different NC clinical pictures. These results, nevertheless, add new elements to our understanding of the complex pathogenic mechanisms involved in susceptibility to infection by T. solium cysticerci and the severity of the ensuing disease.
Assuntos
Sistema Nervoso Central/parasitologia , Interferon gama/genética , Interleucina-2/genética , Interleucina-4/genética , Interleucina-6/genética , Neurocisticercose/genética , Taenia solium/fisiologia , Teníase/genética , Fator de Necrose Tumoral alfa/genética , Animais , Progressão da Doença , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Humanos , Linhagem , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Killer cell immunoglobulin-like receptors (KIRs), expressed on Natural Killer (NK) cells, activate/inhibit NK cell function through interactions with their HLA-A, B and C ligands. KIR3DL1 is one of the most polymorphic genes and its effect varies depending on the interaction of the specific allotype with its Bw4 ligand. We investigated the allelic diversity of KIR3DL1/S1 using sequence based typing and we typed as well, their Bw4 ligands in Mexican Mestizos of Mexico City. The results showed that this population has a great KIR3DL1 allelic diversity with ∗01502 (19.9%), ∗00101 (13.2%) and ∗00501 (12.8%) being the most common alleles, while KIR3DS1 showed predominance of ∗01301 (86%); these data agree with the diversity found in most populations studied. At least one KIR3DL1-HIGH surface expression allele was present in 67.5% of the subjects. Phylogenetic comparisons between Mestizos and 28 different populations showed that allelic diversity of KIR3DL1/S1 was similar in Mexican Mestizos from Mexico and in Hispanics from USA. Knowledge of KIR and MHC diversity worldwide is fundamental for understanding the impact of KIR and KIR-ligand polymorphism on NK cell effector functions and is relevant in genetic anthropology, disease association and transplantation.
Assuntos
Etnicidade/genética , Variação Genética , Antígenos HLA/genética , Receptores KIR3DL1/genética , Receptores KIR3DS1/genética , Adulto , Alelos , Feminino , Frequência do Gene , Humanos , Masculino , México , Pessoa de Meia-Idade , Filogenia , Receptores KIR3DL1/classificação , Receptores KIR3DS1/classificação , Adulto JovemRESUMO
The aim of this study was to determine the role of certain bovine lymphocyte antigens (BoLA) regions in the resistance or susceptibility to Boophilus microplus tick infestation in two different breeds of cattle. The breeds were maintained, one in natural conditions and the second one in an experimental setting at the research station in Martinez de la Torre, Veracruz, Mexico. The study took place from June to August 2001 (natural infestation) using 33 crossbreed steers (crossbreed is here defined as 3/4 European = 1/2 Simmenthal x 1/4 Holstein x 1/4 Zebu, a cross resulting from F1 x Simmenthal), ranging from 15 to 20 months old. Fifty-nine F1 cows (1/2 Holstein x 1/2 Zebu) were included in the experimental setting, infested and followed during 25 days in November 2001 and 2002. Experiment A included thirty-one 2-7-year-old F1 cows, and experiment B included twenty-eight 18-24-month-old F1 heifers. Both groups were analysed separately and were not comparable because of the different infestation methods and genetic background. All ticks > or =4mm long were counted on the total body of F1 animals and on one side of the 3/4 European steers. In this case, susceptible animals were defined when having ticks = X + 1S.D. (29 +/- 16). In the experimental setting susceptibility was defined when the number of ticks was over the 75 percentile (> or =79). DNA was extracted from peripheral blood samples of all animals. The BoLA DRB3, DRBP1, RM185 and BM1815 microsatellite loci were amplified using a PCR method. Genescan software was used for analysis in an ABI sequencer. The SPSS statistical program was used and the comparisons were assessed using the Fisher's exact test. In the naturally infested animals, DRB3-184 was found positively associated with tick infestation (P = 0.018; Pc = NS; OR = 5; EF = 28%). DRBP1-128 was also found to be increased (P = 0.03; Pc = NS; OR = 6; EF = 42%). In the experimentally infested animals, two more loci were found to be associated, BM1815-152 (P = 0.01; Pc = NS; OR = 15; EF = 74%) and DRBP1-130 (P = 0.05; Pc = NS; OR = 4; EF = 77%). None of them remained significant after correction, indicating that a larger sample size is needed to confirm the results. This is the first study showing MHC genes associated with tick infestation based on class II microsatellite polymorphisms. Further studies are needed to confirm the susceptibility traits and to determine haplotype segregation in families.
Assuntos
Doenças dos Bovinos/genética , Doenças dos Bovinos/imunologia , Predisposição Genética para Doença , Antígenos de Histocompatibilidade Classe II/genética , Repetições de Microssatélites/genética , Infestações por Carrapato/veterinária , Animais , Bovinos , Infestações por Carrapato/genética , Infestações por Carrapato/imunologiaRESUMO
The distribution of HLA-DR antigens was investigated in 38 Mexican Mestizo patients with Guillain-Barré syndrome (GBS) and in 100 healthy controls belonging to the same population. IgG, IgM, IgA, CH50, C3, C4 and the number of T and B lymphocytes were also evaluated in the patients. Only DR3 was significantly increased in the patients (Yates' chi 2 = 9.943, Pc = 0.014) and the relative risk for developing the disease was 3.49. These findings support the hypothesis that DR3 or a closely linked Ir gene may play some role in the susceptibility to GBS.
Assuntos
Antígenos de Histocompatibilidade Classe II/imunologia , Polirradiculoneuropatia/imunologia , Adolescente , Adulto , Idoso , Criança , Feminino , Genes MHC da Classe II , Humanos , Masculino , México , Pessoa de Meia-Idade , Polirradiculoneuropatia/genéticaRESUMO
This is the first study on genetic markers in Mexican Mestizos with multiple sclerosis (MS). Patients were born in Mexico, had no family history of MS are middle-class, and have a high-level education. HLA class I, class II determinants, C2, C4, BF, GLO-1, ABO, and Rb red cell systems were analyzed and compared with results of 295 controls. Measles antibodies, glucose, IgG, total proteins, and cell count were measured in cerebrospinal fluid; anti-neuron, T-cell, and B-cell antibodies were determined in serum. MS in Mexican Mestizos was clinically similar to MS reported in high prevalence countries. DRw6, as previously found in Japanese patients, and its subtype, DRw13, were increased in patients in our study (pc = 0.0007, pc = 0.01, respectively), and the combination A3, B7, DR2, was also elevated (pc = 0.003). The polygenicity of the disease is emphasized by the excess of AB group carriers (pc = 0.01). IgG levels were high in patients with DR2 or DRw6 and 67% of the latter had anti-T cell antibodies. Severity of the disease was also related to the DR markers. It is suggested that at least two HLA-DR linked genes and the industrialized environment are important for the expression of MS in Mestizos.
Assuntos
Antígenos de Histocompatibilidade Classe II/genética , Esclerose Múltipla/genética , Sistema ABO de Grupos Sanguíneos/genética , Adulto , Autoanticorpos/imunologia , Linfócitos B/imunologia , Feminino , Marcadores Genéticos , Genótipo , Antígenos HLA/genética , Antígenos HLA/imunologia , Antígenos HLA-DR/genética , Antígenos HLA-DR/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Imunoglobulina G/análise , Masculino , México , Esclerose Múltipla/imunologia , Sistema do Grupo Sanguíneo Rh-Hr/genética , Linfócitos T/imunologiaRESUMO
Mexican Mestizos, who are the result of the admixture of Spanish, Indian, and Black genes, were analyzed for different systems. Three populations from geographical distinct areas were studied: the north (State of Nuevo Leon ), the center (State of Guanajuato), and the highlands (mainly Mexico City). Ten blood group systems (N = 229), STRs (N = 107), HLA-A*, B*, C* (N = 116-167), and DRB1, DQA1, and DQB1 (N = 40, 101, 160, respectively) were analyzed in the samples of the highlands. The three groups cluster together in the same branch: Mestizos from Venezuela, Mediterranean and Jews close to the cluster of Orientals, followed by Amerindians. All markers demonstrate that Indian genes are strongly represented in the highlands: Di(a), O, D(-)(+), s, A*0201, *0206, B*1539 (*1541), *3902, *3905, *3512, *3517, *4002, *4005, Cw*0801, *0304, *0401 among others. Cw*0501, *1203, *1204, and *1601 are of White ancestry. The most frequent haplotypes *0407-*03011-*0302 and *0802-*0401-*0402 are of Indian descent as well. The center and mainly the north show a more Caucasian and Semitic profile. The results demonstrate the high variability resulting from interethnic admixture, suggesting that this mechanism is the main factor responsible for the large diversity found in urban populations.
Assuntos
Antígenos de Grupos Sanguíneos/genética , Genes MHC da Classe II/genética , Genes MHC Classe I/genética , Indígenas Norte-Americanos/genética , Repetições de Microssatélites/genética , Adulto , Feminino , Antígenos HLA/genética , Haplótipos/genética , Humanos , Masculino , México , Hibridização de Ácido Nucleico , Sondas de Oligonucleotídeos , Reação em Cadeia da Polimerase , Sequências de Repetição em Tandem/genética , Tirosina 3-Mono-Oxigenase/genéticaRESUMO
A two stage PCR-SSOP typing procedure, that permitted HLA-B allele assignment, was applied to DNA samples obtained from six diverse populations -Brazilian, Mexican (Series and Mestizos), Cuban (Caucasoid and Mulatto), South African Zulu, Omani, and Singapore Chinese. HLA-B allele frequencies and HLA-A/B two locus haplotype frequencies were compiled for each population.