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1.
Diabet Med ; 33(1): 91-6, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26031759

RESUMO

AIM: Killer immunoglobulin-like receptors (KIRs) and their interaction with HLA class I ligands have been shown to be associated with Type 1 diabetes mellitus. The aim of our study was to investigate the influence of KIR genes and their HLA-C ligands for susceptibility to Type 1 diabetes in patients from Eastern India. METHODS: A total of 135 patients with Type 1 diabetes and 98 healthy subjects from Eastern India were typed for KIR genes and HLA-C ligands using PCR-based genotyping. The frequencies of these genes were compared between patients and controls. RESULTS: Comparison of KIR genes between Type 1 diabetes patients and healthy subjects revealed significantly different frequencies of KIRs 2DL2 and 2DS4. The presence of HLA-C1 was negatively associated with disease. The presence of both HLA-C1 and -C2 showed a negative association with Type 1 diabetes, whereas the absence of C1 and presence of C2 was positively associated with disease. Stratification analysis of HLA-C ligands and KIRs showed significant associations between Type 1 diabetes and 2DL2+/C1-, 2DL2-/C1+, 2DL3+/C1+, 2DL3+/C1- and 2DS2+/C1-. CONCLUSIONS: Our results suggest that the interaction of KIRs with HLA-C ligands are significant and certain combinations contribute to susceptibility to and protection against Type 1 diabetes.


Assuntos
Diabetes Mellitus Tipo 1/genética , Predisposição Genética para Doença , Antígenos HLA-C/sangue , Células T Matadoras Naturais/metabolismo , Polimorfismo Genético , Receptores KIR2DL2/genética , Receptores KIR2DL3/genética , Receptores KIR/genética , Alelos , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/metabolismo , Suscetibilidade a Doenças , Regulação da Expressão Gênica , Frequência do Gene , Estudos de Associação Genética , Antígenos HLA-C/genética , Antígenos HLA-C/metabolismo , Humanos , Índia , Ligantes , Células T Matadoras Naturais/imunologia , Receptores KIR/agonistas , Receptores KIR/sangue , Receptores KIR/metabolismo , Receptores KIR2DL2/agonistas , Receptores KIR2DL2/sangue , Receptores KIR2DL2/metabolismo , Receptores KIR2DL3/agonistas , Receptores KIR2DL3/sangue , Receptores KIR2DL3/metabolismo
2.
Int J Immunogenet ; 43(3): 125-30, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26991115

RESUMO

In this study, we aimed to test the hypothesis that KIR haplotypes (that interact with HLA class I molecules) are associated with susceptibility in patients with T1DM in utero through maternal-foetal interaction of KIR and their HLA class I ligands in Han Chinese population. We determined the KIR genes and KIR/ligand gene combination frequencies in 59 Han Chinese children with T1D and their mothers and compared it with 159 healthy control children and their mothers. The absence of KIR-2DS1 in the mother and the presence of HLA-C2 ligand in the child were negatively associated with type 1 diabetes in the child. Our results indicate that maternal KIR genes and their interaction with foetal HLA-C2 may contribute to the risk of type 1 diabetes among Han Chinese children.


Assuntos
Diabetes Mellitus Tipo 1/genética , Predisposição Genética para Doença , Antígenos HLA-C/genética , Receptores KIR/genética , Adulto , Povo Asiático , Criança , Pré-Escolar , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/patologia , Feminino , Estudos de Associação Genética , Antígenos HLA-C/imunologia , Haplótipos/genética , Histocompatibilidade Materno-Fetal/genética , Humanos , Ligantes , Masculino , Receptores KIR/imunologia
3.
Genes Immun ; 16(8): 541-51, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26513234

RESUMO

The possible interrelations between human leukocyte antigen (HLA)-DQ, non-HLA single-nucleotide polymorphisms (SNPs) and islet autoantibodies were investigated at clinical onset in 1-34-year-old type 1 diabetes (T1D) patients (n=305) and controls (n=203). Among the non-HLA SNPs reported by the Type 1 Diabetes Genetics Consortium, 24% were supported in this Swedish replication set including that the increased risk of minor PTPN22 allele and high-risk HLA was modified by GAD65 autoantibodies. The association between T1D and the minor AA+AC genotype in ERBB3 gene was stronger among IA-2 autoantibody-positive patients (comparison P=0.047). The association between T1D and the common insulin (AA) genotype was stronger among insulin autoantibody (IAA)-positive patients (comparison P=0.008). In contrast, the association between T1D and unidentified 26471 gene was stronger among IAA-negative (comparison P=0.049) and IA-2 autoantibody-negative (comparison P=0.052) patients. Finally, the association between IL2RA and T1D was stronger among IAA-positive than among IAA-negative patients (comparison P=0.028). These results suggest that the increased risk of T1D by non-HLA genes is often modified by both islet autoantibodies and HLA-DQ. The interactions between non-HLA genes, islet autoantibodies and HLA-DQ should be taken into account in T1D prediction studies as well as in prevention trials aimed at inducing immunological tolerance to islet autoantigens.


Assuntos
Autoanticorpos/imunologia , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/imunologia , Antígenos HLA-DQ/genética , Ilhotas Pancreáticas/imunologia , Adolescente , Adulto , Autoanticorpos/genética , Criança , Pré-Escolar , Antígenos HLA-DQ/imunologia , Humanos , Lactente , Polimorfismo de Nucleotídeo Único , Proteína Tirosina Fosfatase não Receptora Tipo 22/genética , Receptor ErbB-3/genética , Adulto Jovem
4.
Roum Arch Microbiol Immunol ; 73(1-2): 43-50, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25518570

RESUMO

BACKGROUND: The population is not always homogeneous in relation to the representation and functioning of genes. Therefore, the presence of allogenicity is a universal phenomenon. The profound variability is noticed among the members of the human population with reference to the resistance against infections and late onset of diseases. In this line, a few sets of alleles which come under the domain of immune function namely KIRs (Killer immunoglobulin-like receptor genes) and HLA-I have been chosen to report in the population of Puttaparthi (India). OBJECTIVES: The genotyping of the population is the current ongoing focus of our team wherein the distribution of the following alleles has been taken up in the mixed ethnic groups of Puttaparthi as a prelude to earmark them as genotypic markers in future studies relating to susceptible diseases. METHODS: The PCR protocols for the identified immune related genes viz., KIR- 2DL1, 2DL2, 2DL3, 2DL4, 2DL5, 3DL1, 3DL2, 3DL3, 3DS1, 2DS1, 2DS2, 2DS3, 2DS4, 2DS5, 2DP1, 3DP1; HLA- C1 and HLA-C2 have been standardized. RESULTS & INTERPRETATION: In the present study, except KIR 2DL2, the other non-framework inhibitory KIR genes were represented at higher percentage and ranged from 57% to 80% in the chosen population which would suggest its higher survival adaptation. Interestingly, the majority of activating KIR genes were least represented and varied between 5% to 32.5% which is also in compliance with the survival adaptation of the chosen population. The carrier gene frequencies of KIRs were compared with the other populations' viz., Chinese Mongolian, Chinese Han, Greek and Brazilian data. The expected heterozygosity of KIR alleles and their rank in gene diversity among the population of Puttaparthi were also discussed.


Assuntos
Receptores KIR/genética , Frequência do Gene , Genótipo , Antígenos HLA-C/genética , Humanos , Índia , Reação em Cadeia da Polimerase
5.
Genes Immun ; 11(5): 406-15, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20445565

RESUMO

The single nucleotide polymorphism 1858C>T in the PTPN22 gene is associated with type 1 diabetes (T1D) in several populations. Earlier reports have suggested that the association may be modified by human leukocyte antigen (HLA), as well as by islet autoantibodies. In a large case-control study of Swedish incident T1D patients and controls, 0-34 years of age, we tested whether the odds ratio (OR) measure of association was dependent on HLA or autoantibodies against the islet autoantigens glutamic acid decarboxylase 65 kDa autoantibodies (GADA), insulin, islet antigen-2, or islet cell. The association between the carrier status of 1858C>T allele in PTPN22 (PTPN22(CT+TT)) and T1D was modified by HLA. In addition, in GADA-positive T1D, the OR was 2.83 (2.00, 3.99), whereas in GADA-negative T1D, the OR was 1.41 (0.98, 2.04) (P for comparison=0.007). The OR of association between PTPN22(CT+TT) and GADA-positive T1D declined with increasing HLA-risk category from 6.12 to 1.54 (P=0.003); no such change was detected in GADA-negative T1D (P=0.722) (P for comparison=0.001). However, the absolute difference in risk between PTPN22(CC) and PTPN22(CT+TT) subjects with high-risk HLA was five times higher than that for subjects with low-risk HLA. We hypothesize that the altered T-cell function because of the PTPN22(1858C>T) polymorphism is exclusively associated with GADA-positive T1D at diagnosis.


Assuntos
Autoanticorpos/metabolismo , Diabetes Mellitus Tipo 1/genética , Predisposição Genética para Doença/genética , Glutamato Descarboxilase/imunologia , Antígenos HLA/genética , Polimorfismo de Nucleotídeo Único/genética , Proteína Tirosina Fosfatase não Receptora Tipo 22/genética , Adolescente , Adulto , Fatores Etários , Autoanticorpos/imunologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Lactente , Recém-Nascido , Masculino , Razão de Chances , Medição de Risco , Suécia
6.
Int J Immunogenet ; 35(6): 439-46, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19046302

RESUMO

Killer immunoglobulin-like receptors (KIRs) are known to modulate natural killer (NK) and NK T-cell function by interacting with human leucocyte antigen (HLA) class I ligands on target cells. The aim of our study was to investigate the influence of KIR2D genes with their HLA-C ligands in susceptibility to type 1 diabetes. A total of 98 type 1 diabetes patients and 70 healthy subjects from Latvia were typed for KIR genes and HLA-C ligands using polymerase chain reaction-based genotyping. The HLA C1+/C2+ combination was positively, and C1-/C2+ combination was negatively, associated with type 1 diabetes. Stratification analysis of KIR/HLA-C ligand combinations showed 2DL2+/C1+, 2DL3+/C1+, and 2DS2+ /C1+ to be positively, and 2DL2-/C1- and 2DS2-/ C1- to be negatively, associated. The presence of 2DL2-HLA-C1 in the absence of 2DS1, 2DS2 confers maximum susceptibility. Absence of 2DL2 and HLA-C1 along with absence of 2DS1 and 2DS2 confer maximum protection. A hypothetical model of KIR/ligand combinations on immune responses and type 1 diabetes susceptibility is proposed. Our results suggest that a combination KIR2DL2- HLA-C1 plays a critical role in susceptibility or protection in Latvians against type 1 diabetes.


Assuntos
Diabetes Mellitus Tipo 1/genética , Predisposição Genética para Doença , Antígenos HLA-C/genética , Receptores KIR2DL2/genética , Adolescente , Criança , Pré-Escolar , Feminino , Frequência do Gene , Genótipo , Humanos , Lactente , Recém-Nascido , Letônia , Masculino , População Branca/genética
7.
Indian J Med Res ; 128(4): 448-61, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19106440

RESUMO

Cu being a transition metal is ubiquitously engaged in biological systems to derive electrons through its participation in several enzymatic reactions. Upon bestowing the significance of Cu in biological systems, an elaborate mechanism is set forth by nature for maintaining Cu homeostasis. As a consequence, a wide variety of proteins viz., family of Cu bearing proteins, cuproenzymes, Cu transporters and Cu chaperone proteins have been manifested for enabling Cu to show its relevance in biological health. In addition, understanding the role of Cu in hepatic and neuronal functions and also in angiogenesis keeps progressing with the advent of novel molecular tools. The studies on genetic defects in Cu metabolism causing abnormalities are providing insights leading to the possible prognostic cues to alleviate the sufferings.


Assuntos
Cobre/fisiologia , Transporte Biológico , Cobre/metabolismo , Homeostase , Humanos
8.
J Assoc Physicians India ; 56: 875-80, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19263687

RESUMO

Epigenetics deals with molecular heritable patterns relating to chromatin, which exists in two alterable and inter-convertible states. The two conformations of chromatin i.e., compact and relaxed are due to epigenetic regulation. The alterations in chromatin normalize gene expression patterns. Thus, the epigenetic marks on chromatin are the deciding factors for either gene silencing or activation. The epigenetics introduced a new term viz., epiallele which deviates from the classical Mendelian allele. The remodeling of chromatin during embryonic phase, post-translational aberrations of chromatin proteins causing cellular dysfunction and possible epigenetic therapies are discussed in the present article. The role of epigenetic mechanisms in triggering / progression of several autoimmune diseases is being emphasized off late. The study of such complex epigenetic processes becomes very important in understanding the etiopathology of the disease as well as in designing target therapies.


Assuntos
Doenças Autoimunes/genética , Cromatina/genética , Epigênese Genética , Predisposição Genética para Doença , Perfilação da Expressão Gênica , Humanos
9.
J Clin Invest ; 95(4): 1505-11, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7706455

RESUMO

Most autoimmune diabetes occurs in those without a diabetic relative, but few cases are identifiable prospectively. To model general population prediction, 491 consecutive newly diabetic children from all of Sweden were tested for autoantibodies to glutamate decarboxylase (GAD65ab), insulin (IAA), and islet cells (ICA), and for HLA-DQ genotypes by PCR; 415 matched control children were tested in parallel. GAD65ab sensitivity/specificity was 70/96%, versus 84/96% for ICA, 56/97% for IAA, 93/93% (any positive), 39/99.7% (all positive), and 41/99.7% (GAD65ab plus IAA). The latter's 25% predictive value was not improved by requiring concomitant high-risk HLA genotypes. GAD65ab were associated with DQA1*0501/B1*0201 (DQ2; P = 0.007) but not DQA1*0301/B1*0302 (DQ8), and IAA with DQA1*0301/B1*0302 (DQ8; P = 0.03) but not DQA1*0501/B1*0201 (DQ2). GAD65ab were more prevalent in females than males (79 vs. 63%; P < 0.0001) but did not vary with onset age nor season. Combining the three antibody assays yielded sufficient sensitivity for screening. GADab were relatively sensitive/specific for diabetes, but even with HLA marker combinations yielded predictive values insufficient for early immunointervention in the low-prevalence general population.


Assuntos
Autoanticorpos , Diabetes Mellitus Tipo 1/diagnóstico , Glutamato Descarboxilase/imunologia , Teste de Histocompatibilidade , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Diabetes Mellitus , Diabetes Mellitus Tipo 1/epidemiologia , Feminino , Humanos , Lactente , Recém-Nascido , Insulina/imunologia , Ilhotas Pancreáticas/imunologia , Masculino , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Caracteres Sexuais , Suécia/epidemiologia
10.
Diabetes ; 44(1): 125-31, 1995 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7813806

RESUMO

The association between human leukocyte antigen (HLA) and insulin-dependent diabetes was studied in a large population-based investigation using genotyping of 425 new-onset patients, 0-14 years of age, and 367 matched control subjects. As many as 97% of patients compared with 75% of control subjects were positive for one or several of DQA1*0301, DQA1*0501, DQB1*0302, or DQB1*0201. Asp-57 DQB was present among 28% of patients, indicating that this residue alone does not confer protection. Combining Asp-57 DQB1 with either Arg-52 DQA1 or Leu-69 DQA1 did not explain susceptibility or protection either. DQA1*0301-DQB1*0302 (DQ8) and DQA1*0301-DQB1*0301 (DQ7) are identical except for four amino acid substitutions in the beta-chain, but DQ8 was positively (odds ratio 8.07; P < 0.001) and DQ7 negatively (odds ratio 0.38; P < 0.001) associated with the disease. Molecular modeling was used to determine whether physiochemical properties such as steric factors and surface electrostatic potentials also differ in a systematic way for various DQ molecules. Amino acids were substituted systematically at the four polymorphic sites, and the solvent-accessible surfaces and electrostatic potentials were computed for each molecule. Dramatic alterations in electrostatic potential were seen for double substitutions at position 45 (G45E) and 57 (A57D) of DQB1. The variation of physicochemical properties due to polymorphic substitutions may be significant to the mechanism of HLA-DQ association with insulin-dependent diabetes, via the effect these property variations have on peptide antigen binding selectivity and subsequent interactions with specific T-cell receptors.


Assuntos
Aminoácidos/análise , Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 1/imunologia , Antígenos HLA-DQ/análise , Adolescente , Sequência de Aminoácidos , Aminoácidos/genética , Aminoácidos/metabolismo , Arginina/análise , Ácido Aspártico/análise , Criança , Pré-Escolar , Diabetes Mellitus Tipo 1/metabolismo , Feminino , Amplificação de Genes , Genótipo , Antígenos HLA-DQ/química , Antígenos HLA-DQ/metabolismo , Humanos , Incidência , Lactente , Leucina/análise , Masculino , Modelos Moleculares , Dados de Sequência Molecular , Polimorfismo Genético , Suécia/epidemiologia
11.
Diabetes Care ; 24(1): 33-8, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11194237

RESUMO

OBJECTIVE: Recent studies have demonstrated that MICA (major histocompatibility complex class I chain-related genes) on the short arm of the chromosome 6 are associated with susceptibility to various autoimmune diseases in Caucasians. The aim of our study was to investigate the role of MICA in type 1 diabetes susceptibility independent of the HLA DR-DQ polymorphism in genetically distinct Koreans. RESEARCH DESIGN AND METHODS: A total of 119 patients selected from Korean Seoul type 1 diabetes registry and 134 nondiabetic unrelated control subjects were typed for exon 5 polymorphism of MICA in addition to HLA DR-DQ typing. A total of 52 simplex families of type 1 diabetes were also studied. RESULTS: The MICA microsatellite allele consisting of six repetitions of GCT/AGC (A6) was present at a significantly lower frequency in the diabetic patient group (Pc < 0.01; Pc = P value after Bonferroni correction) than in the control population. The MICA microsatellite allele consisting of four repetitions (A4) was present at a higher frequency in diabetic patients (P < 0.05). This deviated distribution was not changed even after controlling for the HLA DRB1-DQB1 haplotype. Transmission/disequilibrium test revealed significant deviation of transmission for alleles at the A6 polymorphism within the MICA gene (P < 0.05). CONCLUSIONS: We could assess that the MICA gene might be associated with type 1 diabetes transracially independent of the HLA gene.


Assuntos
Diabetes Mellitus Tipo 1/genética , Genes MHC Classe I/genética , Polimorfismo Genético , Adolescente , Adulto , Alelos , Criança , Pré-Escolar , Frequência do Gene , Genes MHC da Classe II/genética , Genótipo , Haplótipos , Humanos , Coreia (Geográfico) , Desequilíbrio de Ligação , Repetições de Microssatélites , Pessoa de Meia-Idade
12.
J Clin Endocrinol Metab ; 84(10): 3701-7, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10523017

RESUMO

The major histocompatibility complex class I chain-related MIC-A and MIC-B genes are located on chromosome 6 between the histocompatibility leucocyte antigen (HLA)-B and the B-associated transcript genes. The presence of 21-hydroxylase autoantibodies is a sensitive and specific marker of autoimmune Addison's disease. We studied the polymorphism of exon 5 of the MIC-A gene, of intron 1 of the MIC-B gene, and of HLA-DRB1, -DQA1, and -DQB1 genes in 28 autoimmune (21-hydroxylase autoantibody positive) Addison's disease patients and in 75 healthy subjects from central Italy. The MIC-A5.1 allele was significantly more frequent in Addison's disease patients (79%) than in healthy subjects (36%) [odds ratio (OR) = 6.52, corrected P (Pc) = 0.0015], whereas MIC-A6 was significantly reduced in affected subjects (15% vs. 56%, OR = 0.13, Pc = 0.002). The A5.1/A5.1 genotype had an OR for autoimmune Addison's disease as high as 18.0 and an absolute risk of 1 per 1131. In the presence of MIC-A5.1, MICB-CA-25 was significantly increased in Addison's disease patients (25% vs. 4%, OR = 8.0, P = 0.0039, Pc = 0.047). The MICB-CA-17 allele was absent in Addison's disease patients, but present in more than 25% healthy individuals (OR = 0.10, P = 0.0025, Pc = 0.03). Among HLA-DR and -DQ haplotypes, only DRB1*03-DQA1*0501-DQB1*0201 (DR3/DQ2) was significantly more frequent in Addison's disease patients than in healthy subjects, but only in the presence of MIC-A5.1. The frequency of MIC-A5.1 was significantly increased in Addison's disease patients only in the presence of HLA-DR3-DQ2. Our study demonstrates that susceptibility to autoimmune Addison's disease is linked to the MIC-A microsatellite allele 5.1 and that both MIC-A5.1 and HLA-DR3/DQ2 are necessary to confer increased genetic risk for Addison's disease.


Assuntos
Doença de Addison/genética , Doenças Autoimunes/genética , Genes MHC Classe I/genética , Antígenos de Histocompatibilidade Classe I/genética , Polimorfismo Genético/genética , Adolescente , Adulto , Idoso , Criança , Feminino , Genótipo , Antígenos HLA-DQ/genética , Cadeias alfa de HLA-DQ , Cadeias beta de HLA-DQ , Antígenos HLA-DR/genética , Cadeias HLA-DRB1 , Humanos , Masculino , Repetições de Microssatélites , Pessoa de Meia-Idade , Fatores de Risco
13.
J Clin Endocrinol Metab ; 86(8): 3754-60, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11502807

RESUMO

The polymorphism of the major histocompatibility complex class I chain-related A gene is associated with type 1 diabetes mellitus. The major histocompatibility complex class I chain-related A gene 5 allele is significantly more frequent in Caucasian type 1 diabetes mellitus children than in healthy subjects, but no information is available on the association with adult-onset type 1 diabetes mellitus or with the so-called slowly progressive latent autoimmune diabetes of the adult in the same ethnic group. In this study we estimated the frequency of major histocompatibility complex class I chain- related A gene alleles and human leukocyte antigen-DRB1*03-DQA1*0501-DQB1*0201 and human leukocyte antigen-DRB1*04- DQA1*0301-DQB1*0302 in 195 type 1 diabetes mellitus subjects, in 80 latent autoimmune diabetes of the adult subjects, and in 158 healthy subjects from central Italy. Major histocompatibility complex class I chain-related A gene 5 was significantly associated with type 1 diabetes mellitus only in the 1-25 yr age group at diagnosis, and the odds ratio of the simultaneous presence of both major histocompatibility complex class I chain-related A gene 5 and human leukocyte antigen-DRB1*03- DQA1*0501-DQB1*0201 and/or human leukocyte antigen-DRB1*04-DQA1*0301-DQB1*0302 was as high as 54 and higher than 388 when compared with double negative individuals. Adult-onset type 1 diabetes mellitus (age at diagnosis, >25 yr) and latent autoimmune diabetes of the adult were significantly associated with major histocompatibility complex class I chain-related A gene 5.1, which was not significantly increased among diabetic children. Only the combination of major histocompatibility complex class I chain-related A gene 5.1 and human leukocyte antigen-DRB1*03-DQA1*0501-DQB1*0201 and/or human leukocyte antigen-DRB1*04-DQA1*0301-DQB1*0302 conferred increased risk for adult-onset type 1 diabetes mellitus or for latent autoimmune diabetes of the adult. Our study provides demonstration of the existence of distinct genetic markers for childhood/young-onset type 1 diabetes mellitus and for adult-onset type 1 diabetes mellitus/latent autoimmune diabetes of the adult, namely major histocompatibility complex class I chain-related A gene 5 and major histocompatibility complex class I chain-related A gene 5.1, respectively.


Assuntos
Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/imunologia , Antígenos HLA-DQ/genética , Antígenos HLA-DR/genética , Antígenos de Histocompatibilidade Classe I/genética , Adolescente , Adulto , Idade de Início , Idoso , Diabetes Mellitus Tipo 1/epidemiologia , Feminino , Marcadores Genéticos , Genótipo , Haplótipos , Humanos , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Sistema de Registros , Fatores de Risco , Suécia/epidemiologia
14.
Cancer Epidemiol Biomarkers Prev ; 9(10): 1067-70, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11045789

RESUMO

HLA genes have been shown to be associated with cervical intraepithelial neoplasia (CIN), a precursor of cervical cancer. The human papillomaviruses (HPV) types 16 and 18 are the major environmental cause of this disease. Because the immune system plays an important role in the control of HPV infection, the association of polymorphic HLA could lead to a different immune response to control the development of cervical cancer. The aim of this study was to analyze the association between CIN and a microsatellite polymorphism of tumor necrosis factor (TNFa) taking HPV exposure and CIN-associated HLA haplotypes into account. In a nested case-control study in northern Sweden, 64 patients and 147 controls matched for age and sex and derived from the same population-based cohort were typed for TNFA, HLA-DR, and DQ and assayed for antibodies to HPV types 16 and 18. TNFa polymorphism was not associated with CIN per se. However, there was a significant increase in the frequency of TNFa-11 among HPV16-positive and HLA DR15-DQ6 (B*0602) patients compared with HPV16- and HLA-DQ6-negative patients (odds ratios, 5.4 and 9.3, respectively). The relative risk for CIN conferred by the combination of TNFa-11, HLA-DQ6, and HPV 16 positivity was 15. Our study suggests that the TNFa-11 allele is associated with HPV16 infection and associated with CIN in combination with HLA-DQ6 but not by itself.


Assuntos
Antígenos HLA-DQ/genética , Antígenos HLA-DR/genética , Papillomaviridae/patogenicidade , Infecções por Papillomavirus/complicações , Polimorfismo Genético , Fator de Necrose Tumoral alfa/genética , Infecções Tumorais por Vírus/complicações , Displasia do Colo do Útero/genética , Displasia do Colo do Útero/virologia , Neoplasias do Colo do Útero/genética , Adulto , Alelos , Estudos de Casos e Controles , Feminino , Humanos , Repetições de Microssatélites/genética , Medição de Risco , Suécia/epidemiologia , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/virologia , Displasia do Colo do Útero/epidemiologia
15.
J Neuroimmunol ; 85(1): 102-5, 1998 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-9627003

RESUMO

Myasthenia gravis (MG) is characterized by muscle weakness due to autoimmunity against the nicotinic acetylcholine receptor (nAChR). MG is associated with polymorphisms in HLA-DQ genes and the aim of the present study was to characterize structural differences in the peptide binding groove of HLA-DQ molecules positively and negatively associated with MG. Three dimensional models of the positively associated DQ2 (DQB1*02) and negatively associated DQ6 (DQB1*0603) molecules were constructed by homology modeling techniques. The differences in peptide binding properties were primarily localized to peptide-anchor pockets P7 and P9, which might be of importance for the binding of disease-associated peptides from the nAChR.


Assuntos
Antígenos HLA-DQ/análise , Antígenos HLA-DQ/genética , Modelos Moleculares , Miastenia Gravis/imunologia , Humanos
16.
J Neuroimmunol ; 65(2): 125-31, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8964894

RESUMO

The association between myasthenia gravis (MG) and polymorphic amino acid domains in the HLA-DQ molecule was studied in 79 Swedish patients and 155 unrelated, population-based controls. A domain unique for DQB1*0201 was positively associated in MG patients with thymic hyperplasia or an early disease onset, and two domains with residues common to DQA1*01 alleles or DQB1*05 and DQB1*06 alleles were negatively associated in patients with thymic hyperplasia or an early disease onset. Our results suggest that MG associated with thymic hyperplasia and thymoma differ in their HLA-DQ association and thus are likely to have different pathogenic mechanisms.


Assuntos
Antígenos HLA-DQ/genética , Miastenia Gravis/genética , Miastenia Gravis/imunologia , Polimorfismo Genético , Adolescente , Adulto , Idoso , Sequência de Aminoácidos , Criança , Éxons , Feminino , Cadeias alfa de HLA-DQ , Cadeias beta de HLA-DQ , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Miastenia Gravis/fisiopatologia
17.
J Neuroimmunol ; 88(1-2): 137-43, 1998 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-9688335

RESUMO

The aim of this study was to analyze associations between myasthenia gravis (MG) and polymorphisms in the tumor necrosis factor (TNF) region in 79 Swedish patients and 155 unrelated controls. The frequency of the TNFa2 allele of a microsatellite located 3.5 kb upstream of the lymphotoxin alpha (LT-alpha) gene in the TNF region was found to be increased in overall MG patients compared to controls. The frequency of the short 5.5 kb fragment (TNFB * 1) of a bi-allelic NcoI RFLP polymorphism located at the first intron of the LT-alpha gene was increased in patients with an early onset of disease compared to patients with a later onset.


Assuntos
Miastenia Gravis/genética , Polimorfismo Genético/genética , Fator de Necrose Tumoral alfa/genética , Idade de Início , Alelos , Humanos , Íntrons/genética , Linfotoxina-alfa/genética , Repetições de Microssatélites/genética , Miastenia Gravis/epidemiologia , Fragmentos de Peptídeos/genética , Polimorfismo de Fragmento de Restrição , Valores de Referência
18.
Hum Immunol ; 61(2): 148-53, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10717807

RESUMO

Insulin-dependent diabetes mellitus is positively associated with DQ8, DQ2, and DQ6 (DQB1*0604), and negatively associated with DQ6 (DQB1*0602), DQ6 (DQB1*0603), and DQ7 in Swedish caucasians. The protection conferred by DQ6 (DQB1*0602) is stronger in younger individuals and there is decrease in the effect of protection with increasing age. Three-dimensional modeling of the susceptible DQ6 (DQB1*0604) and protective DQ6 (DQB1*0602), which share the same DQA chain (DQA1*0102) but differ in the DQB chain at 6 residues, identifies residue 57 and 70 to be important for protection. Three-dimensional models of the DQ8 molecules were constructed from the coordinates of the DR1 crystal structure and other susceptibility and resistance molecules were made by homology modeling. The positively associated DQ molecules had weakly negative to significantly positive surface electrostatic potentials over the peptide binding and T cell recognition areas, whereas the negatively associated molecules had distinctly more negative areas over the relevant surface. This suggests that the variation in the physicochemical properties such as molecular electrostatic potentials among different DQ molecules are important.


Assuntos
Diabetes Mellitus Tipo 1/genética , Antígenos HLA-DQ/genética , Fatores Etários , Alelos , Predisposição Genética para Doença , Humanos , Fatores Sexuais
19.
Hum Immunol ; 60(10): 970-3, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10566597

RESUMO

Cervical intraepithelial neoplasia (CIN) is associated with human papillomaviruses (HPV) and the HLA genes. The MICA (MHC class I chain-related gene A) is expressed by keratinocytes and epithelial cells and interacts with gamma delta T cells. It is therefore possible that MICA might influence the pathogenesis of CIN and cervical cancer through presentation of viral or tumor antigens. To investigate this, we determined the MICA transmembrane allele frequencies in a prospective population-based cohort study from the Västerbotten County in northern Sweden. 74 women developed CIN. 153 control women who remained healthy during follow up were matched for age. Five polymorphic microsatellite alleles of MICA were identified by a polymerase chain reaction-based (PCR) technique using fluorescent-labeled primers. MICA A5 and A5.1 were the most common alleles in this population. None of the alleles of MICA were associated with disease. The frequency of MICA allele A5 was higher among HPV 18 seropositive than HPV 18 seronegative patients but this difference was not significant after the correction of p value. In conclusion, microsatellite allele polymorphism of MICA transmembrane part is not associated with cervical intraepithelial neoplasia.


Assuntos
Predisposição Genética para Doença , Antígenos de Histocompatibilidade Classe I/genética , Polimorfismo Genético , Displasia do Colo do Útero/genética , Éxons , Feminino , Frequência do Gene , Antígenos HLA-DQ/isolamento & purificação , Humanos , Repetições de Microssatélites , Papillomaviridae/isolamento & purificação , Estudos Prospectivos , Suécia/epidemiologia , Repetições de Trinucleotídeos , Displasia do Colo do Útero/epidemiologia , Displasia do Colo do Útero/etiologia
20.
Hum Immunol ; 62(10): 1153-8, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11600224

RESUMO

Human papillomaviruses type 16 and 18 are the major cause of cervical cancer. However, genetic factors contribute to the propensity of persistent HPV infection and cervical carcinoma. Allelic variants of the human leukocyte genes have shown to be associated with cervical neoplasia. The strongest associations have been found with the genes in the HLA class II region. The aim of this study was to analyze the association of two non-HLA class II markers with invasive cervical cancer. Microsatellite polymorphism of the TNFA gene located in the class III region and a short tandem repeat polymorphism of the MICA gene located in the centromeric end of the HLA class I region were analyzed. Eighty-five patients and 120 matched control individuals from a population-based cohort from Northern Sweden participated in this nested case-control study. MICA was not associated with cervical carcinoma. TNFa-11 frequency was increased in the HPV18 DNA positive patients (OR = 2.84, p = 0.0481, CI = 1.04-7.78, pc = NS). TNFa-11 was not associated with susceptibility to HPV16 infection, but it increased the risk for cervical cancer with the HLA DQ6 (DQA 1*0102-DQB 1*0602) haplotype. Our findings indicate that the association of TNFA with cervical cancer is different with CIN. The extended HLA DQ6-TNFa-11 haplotype is increasing the risk for development of cervical cancer significantly (OR = 3.08, p = 0.0104, CI = 1.30-7.31).


Assuntos
Genes MHC Classe I , Antígenos de Histocompatibilidade Classe I/genética , Polimorfismo Genético/imunologia , Fator de Necrose Tumoral alfa/genética , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/imunologia , Adulto , Idoso , Alelos , Feminino , Genes MHC da Classe II , Genótipo , Antígenos HLA-DQ/genética , Cadeias alfa de HLA-DQ , Cadeias beta de HLA-DQ , Antígenos HLA-DR/genética , Cadeias HLA-DRB1 , Humanos , Pessoa de Meia-Idade , Papillomaviridae/genética , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/imunologia , Infecções Tumorais por Vírus/genética , Infecções Tumorais por Vírus/imunologia , Neoplasias do Colo do Útero/virologia
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