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)

To study the expression of HLA-DQ beta chain alleles associated with type 1 diabetes, mAbs were generated from mice immunized with synthetic peptides representing allelic HLA-DQw7 and HLA-DQw8 beta chain sequences. The splenocytes from immunized mice were fused with myeloma cells, either immediately after or following additional in vitro boosting with peptide. Peptide-specific mAbs, predominantly of the IgG isotype, were isolated only from in vitro boosted splenocytes. Immunoblot analysis showed that several of the mAbs cross-reacted with DQ beta chain molecules. One mAb to a peptide representing DQw8 beta position [49-60] specifically recognised the DQw8 beta chain. Three mAbs to a peptide representing DQw8 beta position [39-52] specifically recognised an epitope consisting of Gly-Val-Tyr in position 45-47, i.e., all DQ beta alleles except DQw7 beta (position 45-47: Glu-Val-Tyr) and DQw2 beta (position 45-47; Gly-Glu-Phe). In FACS analysis these mAbs bound lymphocytes with the same specificity as found by immunoblotting analysis. Thus, by combining in vivo and in vitro immunization we have generated a number of epitope specific monoclonal IgG antibodies that distinguish closely related HLA-DQ beta chain alleles in predetermined positions.
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PMID:Production of epitope specific monoclonal IgG antibodies to HLA class II molecules by combining in vivo and in vitro immunization. 137 72

Humoral immune factors related to type 1 diabetes have been investigated in children with coeliac disease. Anti-insulin (IAAb), immunoglobulin (alpha IgAb), islet cell (ICA) and glucagon autoantibodies were examined in 15 children with coeliac disease at diagnosis (group 1), in 15 children with coeliac disease following a gluten-free diet (group 2) and in 30 control patients (groups 3 and 4). IAAb were present in 27% of group 1 and in 20% of group 2 patients and alpha IgAb were significantly increased in group 1 and 2 patients; two patients in group 2 were positive for ICA; none of the coeliac disease patients were positive for anti-glucagon antibodies. The levels of anti-gliadin antibodies in group 1 were positively correlated with those of alpha IgAb. Coeliac disease-related HLA antigens were not correlated with antibody presence. The presence of diabetes-related humoral immune factors in coeliac disease raises the question as to whether or not they are predictive of subclinical pancreatic damage or whether they are simply indicators of a more general autoimmune diathesis.
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PMID:Diabetes-related autoantibodies do appear in children with coeliac disease. 139 82

Standard regression models for disease incidence data can be used to test for associations between a disease and measured genetic and environmental factors and their interactions. Complications arise when the gene is not observed, requiring segregation and linkage analysis approaches, or when the candidate gene(s) are found to be highly polymorphic, as in the HLA region. We propose a Bayesian approach to the latter problem, in which the log relative risks for all alleles at a given locus are taken to be independent and exchangeable, assuming there is no preferential zygotic assortment and negligible recombination. Multi-locus problems can be addressed either by adding exchangeable interaction terms or by adopting a multivariate prior for haplotype effects. Some simulations based on our current work on family studies of IDDM are discussed.
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PMID:Empirical Bayes methods for testing associations with large numbers of candidate genes in the presence of environmental risk factors, with applications to HLA associations in IDDM. 141 24

Type 1 diabetes mellitus is known to be a heterogenous disease which is frequently complicated with other autoimmune thyroid diseases (AITD). The present study was designed to investigate the clinical characteristics and HLA antigens in Japanese Type 1 diabetic patients with AITD. Subjects were 25 Type 1 diabetic patients with AITD (13 Graves' disease and 12 Hashimoto's thyroiditis) and 32 Type 1 diabetic patients without AITD. Compared with Type 1 diabetic patients without AITD, age at onset of diabetes was later and positive ICA persisted much longer in the diabetic patients with AITD. Compared with normal controls, DR9 was increased in the patients with AITD, while DR4 was increased in those without AITD. Type 1 diabetic patients with AITD were characterized by the late onset of diabetes, persistent ICA and increased association with DR9. These results suggest that immunological and genetic heterogeneity may exist within Japanese Type 1 diabetic patients.
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PMID:Type 1 (insulin-dependent) diabetes mellitus with coexisting autoimmune thyroid disease in Japan. 142 12

To determine whether genetic markers can improve the predictive value of islet cell antibodies for development of Type 1 (insulin-dependent) diabetes mellitus, 536 siblings aged 2-29 years were consecutively enrolled in a 8-year prospective survey. The risk of developing diabetes was estimated, using life-table methods, by years of follow-up and age, according to genetic factors (shared HLA-haplotypes, DR antigens, C4 allotypes) and islet cell antibody status. Fifteen siblings (2.8%) developed Type 1 diabetes during the study period (risk 4.4% after 8 years, 4% by age 22 years). DR3,4 heterozygosity identified higher risk (16% after 8 years, 12% by age 22 years, p less than 10(-5)) than HLA-identity (10% and 7%, respectively, p less than 0.01); risks for DR3 or DR4 positive and for haplo-identical siblings were low (4%, 3% and 4.4%, respectively, NS). C4BQO also conferred significant risk (11% vs 3% in non-C4BQO siblings, p less than 0.01). The predictive value of genetic markers alone was poor (12% for DR3,4, 7% for HLA-identity, 9% for C4BQO) compared with that of islet cell antibody levels greater than 4 Juvenile Diabetes Foundation units (41%, risk 56% after 8 years, p less than 10(-7)). HLA markers significantly contributed to risk prediction in combination with islet cell antibodies: islet cell antibody-positive DR3,4+ subjects had the highest risk (70% after 8 years, predictive value 58%, p less than 10(-7)) compared with islet cell antibody-positive DR3,4- (37% and 20%, respectively) and islet cell antibody-negative DR3,4+ (5% and 3.6%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Life table analysis of the risk of type 1 (insulin-dependent) diabetes mellitus in siblings according to islet cell antibodies and HLA markers. An 8-year prospective study. 145 52

Major determinants of susceptibility to Type 1 (insulin-dependent) diabetes (IDDM) have been mapped to the HLA complex, near to or identical with genes encoding class II molecules. The association of IDDM with HLA-DR3 and/or DR4 antigens and the highest risk for DR3/4 heterozygotes suggest a synergistic effect of the two haplotypes. The characterization at the molecular level of the class II region has provided evidence that DQ rather than DR determinants may primarily influence the disease. In caucasians the susceptibility strongly correlates with the absence of aspartic acid at position 57 on the DQ beta chain and/or the presence of arginine at position 52 on the DQ alpha chain. The formation of a putative DQ susceptibility molecule (DQ alpha Arg52+, DQ beta Asp57-) accounts best for the disease associations when trans-complementation between alpha and beta chains encoded by different haplotypes is postulated to explain the excess of heterozygotes. Observations in other populations and in animal models indicate, however, that other residues on DQ alpha and beta chains, other class II (DR beta) molecules and non-HLA linked genes also contribute to the susceptibility. The mechanism(s) by which susceptibility determinants influence IDDM is not known. It is probably in relation with the role of class II molecules in the antigen presentation to T lymphocytes.
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PMID:[The role of the HLA system in the genetics of Type I diabetes mellitus]. 145 12

Genetic susceptibility alleles have been identified at the DQ HLA region. The aim of the present study was to confirm the value of these markers, and to evaluate the respective weight in the risk of the different alleles at the DQA1 and DQB1 levels, identified by restriction mapping after polymerase chain reaction on exon 2. A significant enrichment in DQB1 alleles encoding for an aminoacid different from Aspartic acid at position 57 (NA) was observed in diabetic (n = 213) in comparison to control (n = 93) children (94% vs 52%; p < 10(-8)). Not all the given NA/NA allelic combinations were equally and positively associated to the disease. Homozygous "Ala/Ala" combinations carried the highest relative risk (OR = 12.3; p < 10(-8)), and among them, the *0201/*0302 genotype was more positively associated to type 1 diabetes (OR = 66; p < 10(-8)). A significant enrichment in DQA1 alleles encoding for Arginine at position 52 in diabetic children was also observed (82% vs 40%; p < 10(-8)). The *0301/*0501 (Arg/Arg) genotype was significantly associated to Type 1 diabetes (OR = 16.2; p < 10(-4)). The highest risk was carried by the whole genotype, a result which could be expected from the known linkage desequilibrium between HLA-DQA1 and DQB1, DRB1 loci. The frequency of Ala DQB1 alleles was low in the background non-at-risk population, although the incidence of the disease is low in our country.
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PMID:[Respective weight of genotypes DQA1 and DQB1 associated with insulin-dependent diabetes in French children]. 145 18

Insulin-dependent diabetes mellitus (IDDM), or type I diabetes, is the end result mainly of a T-cell mediated autoimmune destruction of pancreatic islet beta cells. Genetical and environmental factors are both of importance in the pathogenesis. Genes in the HLA complex seem to be the most important genetical factors. Among Blacks, Caucasoids and Orientals, IDDM susceptibility is associated with some particular combinations of DQA1 and DQB1 genes in cis or trans position. This strongly argues that susceptibility is primarily associated to the corresponding HLA-DQ molecules themselves. However, weaker contributions by other genes in the HLA complex cannot be excluded. Similarly, a dominant protection is strongly associated with some other DQ molecules, in particular HLA-DQ6, in all three ethnic groups. The function of HLA-DQ (and other class II) molecules is to present peptide-fragments of antigens to CD4+ T cells (mainly helper T cells). Thus, the recognition of certain islet beta cell derived peptides by self-reactive CD4+ T cells, may be an initial event in the pathogenesis. The DQ molecules involved in IDDM susceptibility or protection may exert their function either during thymic development of potential self-reactive CD4+ T cells, or by preferential presentation of certain beta-cell derived peptides to CD4+ T cells, or both. The finding that certain DQ molecules as such confer IDDM susceptibility may lead to new methods to prevent IDDM, for example by using blocking peptide analogues.
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PMID:Role of HLA genes in predisposition to develop insulin-dependent diabetes mellitus. 148 49

An increasing bulk of evidence suggests that type 1 (insulin-dependent) diabetes mellitus is an autoimmune disease with a strong immunogenetic background. 1st-degree relatives of type 1 diabetic patients, especially HLA-identical individuals, bear an increased risk to develop the disease. The autoimmune reactions are pronounced at the onset of disease where an infiltration of islets with T and B lymphocytes, plasma cells and macrophages can be observed. Autoreactive T lymphocytes play a crucial role among effector mechanisms which finally lead to a selective destruction of pancreatic beta cells. Disease-specific autoantibodies (Ab) include cytoplasmic islet cell Ab (ICA), islet cell surface Ab (ICSA), Ab to the 64KD islet cell protein and Ab to insulin (IAA). As ICA can be detected months or years before the onset of clinical disease, testing of individuals at risk or population screening programs can help to recognize subclinical insulitis. High titers of ICA and high levels of IAA, as measured by radioimmunoassay, indicate a high risk for progression to type 1 diabetes. A blunted first phase insulin response in the i.v. glucose tolerance test is the most sensitive sign of an irreversible metabolic deterioration. It is likely that immunotherapy at a prediabetic state will be more efficacious than its initiation after the clinical manifestation of diabetes. However, the appropriate immunotherapeutical strategies are yet to be worked out.
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PMID:Etiology and pathogenesis of type 1 diabetes. 149 Jun 74

We analyzed the overall results of 24 simultaneous pancreas and kidney transplantations (SPK), performed in our hospital between April 1986 and June 1990. All patients had type I diabetes mellitus and end-stage renal failure. We used bladder drainage of the pancreatic exocrine secretions through a duodenocystostomy. The blood vessels of both grafts were anastomosed to the iliac vessels. The immunosuppressive management was triple-therapy with cyclosporin, azathioprine and prednisone. All organs were transplanted without matching donors and recipients for HLA. At the time of transplantation, mean recipient age was 37 yr; the average duration of diabetes was 22 yr. After disappointing results in the first 4 patients, the pancreas was placed intraperitoneally instead of extraperitoneally and the antibiotic drug regimen was altered. In the second group (n = 20), patient survival was 100%; 1-yr pancreas and kidney graft survival were 65 and 62%, respectively. Duration of hospitalization and pancreas and kidney graft loss were positively correlated with the number of rejection episodes. After 1 yr of follow-up, the mean creatinine clearance was 62 ml/min and the mean HbA1c was 5.5%. Blood glucose levels and oral glucose tolerance tests were also normal. We conclude that patient and graft survival after SPK are satisfactory, although rejection-related morbidity is still a major problem.
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PMID:Simultaneous pancreas and kidney transplantation: a feasible procedure in selected patients. 149 98


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