Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011854 (type 1 diabetes)
 20,749 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Soluble HLA-DR401 or -DR404 tetramers containing a peptide corresponding to an immunodominant epitope from human GAD65 were used to analyze peripheral blood T-cells of newly diagnosed type 1 diabetic patients and at-risk subjects. Peripheral blood mononuclear cells were expanded on antigen-presenting cells presenting GAD65 peptide and subsequently activated with specific plate-bound class II-peptide monomers. T-cell activation defined in flow cytometry by CD4(high) and/or CD25 markers were observed in all type 1 diabetic patients and some at-risk subjects, but not in normal control subjects. The activated T-cells stained positive with tetramers containing the GAD65 epitope 555-567. Tetramer-positive cells were CD4(high) T-cells with high avidity for an immunodominant GAD65 T-cell epitope. Phenotyping of T-cells utilizing HLA class II tetramers provides a new tool to characterize the autoimmune response in type 1 diabetes.
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PMID:Detection of GAD65-specific T-cells by major histocompatibility complex class II tetramers in type 1 diabetic patients and at-risk subjects. 1197 33

Genetic studies of malnutrition-related diabetes are few. We have analyzed the HLA class II gene polymorphism in malnutrition-modulated diabetes mellitus (MMDM), which was previously referred to as protein-deficient diabetes mellitus (PDDM) in the 1985 WHO classification. Insulin-dependent diabetes mellitus (IDDM) is a polygenic disorder with an autoimmune basis for disease development. In addition to HLA, a second susceptibility locus for IDDM has been identified to lie in the major histocompatibility class III region. Both IDDM and MMDM in eastern Indians are associated with DR3-DQ2 but not DR4-DQ8. The presence of autoantibodies to IDDM autoantigens in clinical MMDM either identifies the slow-onset form of IDDM or suggests autoimmunity different from that in IDDM. Our study demonstrates that the presence of GAD65 antibody and DR3-DQ2 positivity in MMDM patients identifies the underlying autoimmune mechanism in the etiology in eastern India. In autoantibody-negative MMDM patients an association with DR7-DQ2 is identified. The date obtained also indicate the possibility that MMDM can coexist with IDDM in these patients and that malnutrition could be one of the reasons for the slower onset in IDDM-prone individuals. The association of DR7-DQ2 suggests that there is a different immunogenetic background to MMDM than to IDDM. MICA is located in the MHC class I region and is expressed by monocytes, keratinocytes, and endothelial cells. Sequence determination of MICA gene identifies trinucleotide repeat (GCT) microsatellite polymorphism in exon 5. Five alleles with 4, 5, 6, and 9 repetitions of GCT or 5 repetitions of GCT with 1 additional nucleotide insertion (GGCT) are identified. The alleles are A4, A5, A5.1, A6, and A9. We studied the association of MICA alleles with IDDM (n = 52) and MMDM (n = 41) patients and healthy controls (n = 73) from Cuttack, eastern India. MICA was typed by PCR amplification, and fragment sizes were determined in an ABI prism DNA sequencer. Allele 9 of MICA is positively and allele 4 negatively associated with MMDM patients compared to controls. Allele 5 is positively associated with IDDM (OR 2.64, P < 0.05) when compared to controls. Our findings suggest that MMDM is immunogenetically different from IDDM in eastern India and that MIC-A is important in the pathogenesis of MMDM patients from Cuttack in eastern India.
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PMID:Immunogenetic studies on malnutrition-modulated diabetes mellitus. 1202 Oct 94

We examined the frequencies of autoantibodies to glutamate decarboxylase, GAD65, protein tyrosine phosphatase, IA-2/ICA512, and insulin, and of HLA class II markers in ICA-positive first-degree relatives of patients with type 1 diabetes. Our results indicate that while the presence of HLA susceptibility markers is associated with anti-islet autoantibodies, protective DQB1 markers do not absolutely prevent development of autoantibodies or progression to autoimmune diabetes.
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PMID:Autoantibodies and HLA susceptibility markers in Canadian first-degree relatives of patients with type 1 diabetes. 1202 Nov 12

HLA class II profile was evaluated in 64 Brazilian patients presenting with type 1 diabetes mellitus. Although the Brazilian population is highly miscegenated, HLA-DRB1*301, DRB1*04, DQB1*0302, and DQB1*0201 alleles, which are associated with the development of type 1 diabetes in several Western populations, were also overrepresented in Brazilian patients. In addition to HLA-DRB1*15 and DQB1*0602 alleles, DRB1*11, DRB1*13, and DQA1*01 allele groups were associated with protection against the development of type 1 diabetes in Brazilian patients.
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PMID:HLA-DRB1, DQB1, and DQA1 allele profile in Brazilian patients with type 1 diabetes mellitus. 1202 Nov 29

The HLA class II molecules play a critical role in the processing and presentation of specific peptides derived from autoantigens of pancreatic beta cells or gluten for T cell scrutiny in IDDM and CD. In the present study, extended DR3-positive haplotypes associated with autoimmunity in northern Indian patients have been reported. The haplotype A26-B8-DR3 was the most common autoimmunity-favoring haplotype encountered among these patients. This association is, indeed, unique to Indian autoimmune patients, as it replaces the otherwise most commonly associated Caucasian haplotype A1-B8-DR3 (AH8.1) in this population. Further, CD patients revealed 100% association with DQB1*0201 along with DQA*0501 (97%) either in cis or trans configuration.
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PMID:Immunogenetics of autoimmune diseases in Asian Indians. 1202 Nov 36

The HLA class II molecule, DQ6, confers strong natural protection against the development of type 1 diabetes. The mechanism of disease protection is unknown, but is likely to be related to the function of the molecule in antigen presentation. In order to investigate this function, we have created an in vitro model which expresses DQ6 in isolation by introducing the relevant DQ alleles into an Epstein-Barr virus (EBV)-transformed, human leucocyte antigen (HLA) class II-deficient B cell line, bare lymphocyte syndrome (BLS)-1. A recent report suggested that the expression of transferred genes in human EBV-transformed B cells might be limited in duration. We present a plasmid-based transfection method that allows long-term stable expression of the DQ molecule. The DQA1*0102 and DQB1*0602 alleles were cloned into the pCIneo expression vector and the constructs were introduced into BLS-1 by electroporation. Stable transfectants were selected using magnetic sorting and cloned by limiting dilution. Two clones were shown to express functionally active DQ6 molecules even after 14 months of continuous culture. These clones will be used in functional studies to investigate the antigen binding and T-cell activation properties of the DQ6 molecule.
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PMID:Long-term expression of an HLA-DQ molecule in the EBV-transformed bare lymphocyte cell line, BLS-1, using a plasmid vector. 1202 63

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED, OMIM 240300) is a rare autoimmune disease caused by mutations in the autoimmune regulator (AIRE) gene on chromosome 21q22.3. This monogenic disease provides an interesting model for studies of other common and more complex autoimmune diseases. The most common components of APECED are chronic mucocutaneous candidiasis, hypoparathyroidism, and Addison's disease, but several other endocrine deficiencies and ectodermal dystrophies also occur and the phenotype varies widely. The AIRE genotype also varies; 42 different mutations have been reported so far. To understand the complexity of the phenotype, we studied the AIRE and human leukocyte antigen (HLA) class II genotypes in a series of patients with APECED. The only association between the phenotype and the AIRE genotype was the higher prevalence of candidiasis in the patients with the most common mutation, R257X, than in those with other mutations. Addison's disease was associated with HLA-DRB1*03 (P = 0.021), alopecia with HLA-DRB1*04- DQB1*0302 (P < 0.001), whereas type 1 diabetes correlated negatively with HLA-DRB1*15-DQB1*0602 (P = 0.036). The same HLA associations have previously been established for non-APECED patients. We conclude that mutation of AIRE per se has little influence on the APECED phenotype, whereas, in contrast to earlier reports, HLA class II is a significant determinant.
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PMID:AIRE mutations and human leukocyte antigen genotypes as determinants of the autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy phenotype. 1205 Feb 15

Human leukocyte antigen A (HLA-A) genotypes were determined for samples from 283 multiplex, Caucasian, type 1 diabetes families from the Human Biological Data Interchange (HBDI) using an immobilized probe assay. Distribution of HLA-A alleles transmitted to patients was significantly different from that in affected family-based controls (AFBAC) (p = 0.004). Transmission disequilibrium test (TDT) analysis revealed differential transmission of several HLA-A alleles from parents to affected offspring. HLA class II DRB1 and DQB1 loci were also typed, allowing assignment of HLA-A alleles to haplotypes and calculation of linkage disequilibrium values. Some of the apparent effects of HLA-A alleles on type 1 diabetes susceptibility were attributable to linkage disequilibrium with DR and DQ alleles, although others were not. The differences in frequencies between patients and controls of alleles A*0101, A*2402, and A*3002 could not be explained by linkage disequilibrium alone. Our results suggest an important role for class I antigens in modulating susceptibility to type 1 diabetes.
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PMID:The HLA class I A locus affects susceptibility to type 1 diabetes. 1212 73

The contribution of HLA genes to the genetic risk for celiac disease (CD) has been known for a long time. Recent publications have pointed to the possibility that a second, independent susceptibility locus could be located in the same genomic region, and a triplet repeat polymorphism in exon 5 of the gene MHC class I chain-related protein A (MICA; located between TNFA and HLA-B) has been associated with several autoimmune disorders, including type 1 diabetes mellitus (DM1) and Addison's disease. On the other hand, a single amino acid change in exon 3 of MICA (M129V) has been shown to strongly reduce MICA binding to NKG2D, an activating natural killer receptor expressed also on T cells, and this could have significant effects on autoimmune reactions. In this study, we have analyzed the contribution of these polymorphisms to CD in 37 Basque families, and have constructed MICA-HLA-DRB1 haplotypes to determine whether MICA has an effect independent from the HLA class II conferred risk. In our population, HLA-DRB1*0301 was associated with an increased risk for CD, while HLA-DRB1*1501 conferred protection from the disease (OR: 7.38 and 0.06, respectively). On the other hand, MICA allele A4 was positively associated with the disease (OR: 4.69) whereas allele A9 showed a trend towards protection (OR: 0.18), although significance did not hold after correction. No association of the exon 3 biallelic polymorphism was observed. A positive allelic association was found for haplotypes A5.1-DRB1*0301 (associated with risk for disease), A4-DRB1*0301 and A6-DRB1*07. In view of our results, both HLA-DRB1 and MICA are associated with CD, but stratification analysis did not show any independent contribution of the MICA polymorphisms analyzed to CD risk. Besides, MICA allele A4 (also A5.1 was associated with risk for CD and other diseases) is in strong linkage disequilibrium with HLA-DRB1*0301. Finally, the major histocompatibility complex region's conferred susceptibility to CD, at least in Basque, is very similar to that observed for DM1, with shared risk and protective haplotypes.
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PMID:HLA-DRB1 and MHC class 1 chain-related A haplotypes in Basque families with celiac disease. 1236 85

The genetic predisposition to type 1 diabetes among Filipinos was examined by PCR/SSOP HLA class I and II typing of 90 patients and 94 general population controls. The HLA-DRB1, DQB1, and the A, B, and C loci were typed using the reverse SSO probe line-blot method while the DPB1 and DPA1 loci were typed using the SSO probe dot blot method. The Filipino population has a distinctive frequency distribution of HLA class II alleles as well as linkage disequilibrium patterns: a DR-DQ haplotype, unique to Filipinos, contains a DRB1 allele (*0405) positively associated with type 1 diabetes in other populations and DQA1 and DQB1 alleles (*0101-*0503) that are negatively associated in other populations. Specific DR-DQ haplotypes or alleles could be identified as susceptible, neutral or protective based on the distribution among Filipino patients and controls. The DR9 and DR3 haplotypes showed the most dramatic increase among patients (0.156 vs 0.063) and (0.172 vs 0.042), respectively. Among Filipinos, the DR3/9 genotype confers approximately the same risk as the well-known high-risk DR3/4 genotype, similar to that for DR3/3 and DR9/9. The common DR2 haplotype in the Philippines (DRB1*1502-DQB1*0502) was only slightly decreased in type 1 diabetic patients (0.200 in patients vs 0.270 in controls). Another DR2 haplotype, DRB1*1502-DQB1*0501, was significantly decreased among patients. In addition, haplotypes containing DQB1*06 alleles, such as the DRB1*0803-DQB1*0601 (OR = 0.1), are strongly protective. The DR4 allele group was also increased in Filipino patients compared to controls. In this population there is, as in other populations, a hierarchy of type 1 diabetes associations among the many different DR4 haplotypes (n = 15). The high-risk haplotypes in this population are the very rare DRB1*0405-DQB1*0302 and DQB1*0405-DQB1*0201, followed by the more common DRB1*0405-DQB1*0401 and DRB1*0405-DQB1*0402. The DRB1*0403-DQB1*0302 is protective. The DRB1*0405-DQB1*05031 haplotype, which is unique to Filipinos, appears to be "neutral". HLA-DPB1*0202 was significantly increased among patients (0.056 vs 0.011; with OR = 5.3); this increase does not appear to simply reflect linkage disequilibrium with high risk DR-DQ haplotypes. The observed distribution of HLA class II alleles among Filipino patients and controls strongly supports the notion that specific combinations of alleles at the DRB1, DQB1, DQA1, and DPB1 loci are critical in determining the risk for type 1 diabetes. Specific HLA class I alleles also show significant associations with type 1 diabetes in this population. HLA-A*2402 and *2403 were increased among patients; however, 2407 was decreased. Inaddition, A *1101 was significantly decreased among patients (OR = 0.51). Moreover, these HLA-A associations do not appear attributable to linkage disequilibrium with the DR-DQ region. The allele B*5801 was increased in patients while B*1301 was decreased; both of these associations, however, reflected linkage disequilibrium with high-risk and with protective DR-DQ haplotypes, respectively. The HLA-C*0102 and *0302 alleles were increased (0.089 vs 0.037 and 0.122 vs 0.064) while C*1502 and *0702 (0.028 vs 0.080 and 0.217 vs 0.330) were decreased. The observed associations of C*0102 and C*1502 do not simply reflect linkage disequilibrium with high-risk DR-DQ haplotypes. Thus, specific HLA class I-A and C alleles were associated with type 1 diabetes in the Filipinos and may, in combination with high risk DR-DQ haplotypes, significantly modify disease risk.
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PMID:The association of specific HLA class I and II alleles with type 1 diabetes among Filipinos. 1244 15


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