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)

Two major types of diabetes have been recognized since the late 1930s. However, in recent times there have been major changes in classification and understanding of these types, including improved knowledge of maturity-onset diabetes in the young, with the identification of mutations relating to impaired insulin secretion and the recognition of slow-onset type 1 diabetes in adults now designated as latent autoimmune diabetes in adults (LADA). A major problem area in diabetes classification concerns cases of slowly progressive forms of type 1 and type 2 diabetes, particularly in adults aged 25-50 years. This is a more contemporary problem because cases of type 2 diabetes are presenting at an increasingly younger age. In the landmark U.K. Prospective Diabetes Study of type 2 diabetes, islet cell antibodies (ICAs) and antibodies to glutamic acid decarboxylase (anti-GAD) were measured at diagnosis in 3,672 patients. The overall proportion with ICAs was 6%, and anti-GADs was 10%. These subjects clearly had type 1 diabetes or LADA by both phenotypic and genotypic features. The presence of auto antibodies correlated particularly with a younger age and phenotypic features consistent with type 1 diabetes (e.g., early age at diagnosis, lower BMI, and reduced beta-cell function). Overall, of patients requiring insulin by 6 years, 38% were anti-GAD+ at baseline compared with 5.3% of those not on insulin at 6 years. Antibodies to GAD indicate an underlying autoimmune process and have a high positive predictive value for type 1 diabetes and future insulin dependency in adults.
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PMID:Crucial points at diagnosis. Type 2 diabetes or slow type 1 diabetes. 1009 1

A prospective study over 10 years on the natural history of beta-cell function in islet cell antibody (ICA)-positive NIDDM disclosed a characteristic findings of slowly progressive IDDM distinct from those of acute onset IDDM. The characteristics includes: (1) the clinical phenotype at the onset of diabetes is non-insulin requiring, (2) the onset is late age, (3) beta-cell failure progresses slowly over several years with persistently positive low-titer ICA and high titer of GAD antibodies, (4) pathological study on autopsied pancreas demonstrated that beta-cell loss is incomplete, and exocrine pancreas is often atrophied with cell infiltration of CD8+ T lymphocytes, (5) higher family history of NIDDM, and (6) association with some genetic predisposition including HLA-DQA1*0301-DQB1*0401 and/or mitochondrial gene mutation at nucleotide pair 3243, and a lack of association with HLA-A24. These results are sharply contrast with acute onset IDDM, suggesting a presence of distinct subtype of IDDM in Japanese population. We also demonstrated that small dose of insulin therapy was effective for the suppression of immunological beta-cell failure.
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PMID:[Slowly progressive IDDM]. 1019 41

The possible relation between HLA-DQ genotypes and both frequencies and levels of autoantibodies associated with IDDM was assessed by examining HLA-DQB1 alleles and antibodies to islet cells (ICA), insulin (IAA), glutamic acid decarboxylase (GADA) and the protein tyrosine phosphatase-related IA-2 molecule (IA-2A) in 631 newly diagnosed diabetic children under the age of 15 years. ICA were found in 530 children (84.0%), while close to half of the subjects (n = 307; 48.7%) tested positive for IAA. GADA were detected in 461 index cases (73.1%), with a higher frequency in those older than 10 years (78.9% versus 69.2% in the younger ones; P = 0.006). More than 85% of the children (n = 541; 85.7%) tested positive for IA-2A. Altogether there were only 11 children (1.7%) who had no detectable autoantibodies at diagnosis. There were no differences in the prevalence of ICA or GADA between four groups formed according to their HLA-DQB1 genotype (DQB1*0302/02, *0302/X (X = other than *02), *02/Y (Y = other than *0302) and other DQB1 genotypes). The children with the *0302/X genotype had a higher frequency of IA-2A and IAA than those carrying the *02/Y genotype (93.8% versus 67.3%, P < 0.001; and 49.0% versus 33.6%, P = 0.002, respectively). The children with the *02/Y genotype had the highest GADA levels (median 36.2 relative units (RU) versus 14.9 RU in those with *0302/X; P = 0.005). Serum levels of IA-2A and IAA were increased among subjects carrying the *0302/X genotype (median 76.1 RU versus 1.6 RU, P = 0.001; and 50 nU/ml versus 36 nU/ml, P = 0.004) compared with those positive for *02/Y. Only three out of 11 subjects homozygous for *02 (27.3%) tested positive for IA-2A, and they had particularly low IA-2A (median 0.23 RU versus 47.6 RU in the other subjects; P < 0.001). The distribution of HLA-DQB1 genotypes among autoantibody-negative children was similar to that in the other patients. These results show that DQB1*0302, the most important single IDDM susceptibility allele, is associated with a strong antibody response to IA-2 and insulin, while GAD-specific humoral autoimmunity is linked to the *02 allele, in common with a series of other autoimmune diseases as well as IDDM. We suggest that IA-2A may represent beta cell-specific autoimmunity, while GADA may represent a propensity to general autoimmunity.
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PMID:Disease-associated autoantibodies and HLA-DQB1 genotypes in children with newly diagnosed insulin-dependent diabetes mellitus (IDDM). The Childhood Diabetes in Finland Study Group. 1020 8

It is not clear if a Th1/Th2 imbalance in Type 1 diabetes (insulin-dependent diabetes mellitus, IDDM) would lead to a particular antigen-specific IgG subclass dominant as had been shown in the mouse model. In new-onset Type 1 diabetics, an autoantibody response to glutamate decarboxylase (GADab) is frequently observed but the GADab subclass repertoire is not well-established. We determined the systemic levels of representative Th1 and Th2 cytokines and the GADab IgG subclass distribution in 41 Chinese IDDM patients of whom 26 were recently diagnosed (< or = 1 year) and 32 had GADab, to ascertain a likely association of antigen-specific antibody isotype and the Th1/Th2 dichotomy. With high-sensitivity ELISA systems that measure sub-picogram cytokine concentrations, 26 of the 41 patients (63.4%) had at least one of the pro-inflammatory Th1 cytokines (TNF-alpha, IFN-gamma and IL-12) detected. Fewer patients (4/41) had the anti-inflammatory Th2 cytokine IL-4 detected. For IL-10, all subjects had measurable quantities but only three diabetics had levels above the upper limit for healthy subjects (n = 20). Grouped according to the profile of detectable cytokines, there were 24 Th1, 2 Th2 and 2 Th0 patterns. GAD-specific IgG1 antibody was more frequently expressed; 22 of 32 GADab[+] patients. The rank order for the GADab subclasses was IgG1 > 4 > 3 > 2; IgG2 was found in 11 GADab[+] patients. Recent-onset diabetics have a similar ranking of the GAD-specific IgG subclasses. In human Type 1 diabetes, a predominance of GAD-specific IgG1 antibody response is observed together with a dominant Th1 cytokine pattern.
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PMID:Systemic levels of cytokines and GAD-specific autoantibodies isotypes in Chinese IDDM patients. 1022 65

Investigations of humans and nonobese diabetic mice suggest that proinsulin and/or a fragment of the region spanning C-peptide and the B-chain of insulin (i.e., proinsulin peptide) may serve as key autoantigens in IDDM. Therefore, we analyzed cellular immune reactivities against these molecules in people with or at varying risks for the disease to clarify their role in the pathogenesis of IDDM. In vitro peripheral blood mononuclear cell (PBMC) responses against these antigens, a control antigen (tetanus toxoid), and phytohemaglutinin were determined in 60 individuals with newly diagnosed IDDM (< or = 1 day from diagnosis) in 34 islet cell cytoplasmic autoantibody- and/or insulin autoantibody-negative first-degree relatives of the IDDM subjects, and in 28 autoantibody-negative control subjects. Unlike previous reports suggesting diabetes-associated elevations in cellular immunity to other beta-cell antigens (e.g., GAD, IA-2, etc.), we observed equivalent levels of phytohemaglutinin stimulation and cellular proliferation in all groups against these antigens (all P values were not significant). The mean stimulation index +/- SD and frequency of reactivity to proinsulin for healthy control subjects and IDDM patients, respectively, were as follows: 1 microg/ml (1.5 +/- 1.0, 1 out of 17 [6%]; 1.9 +/- 1.4, 4 out of 33 [12%]); 10 microg/ml (1.7 +/- 1.3, 1 out of 17 [6%]; 1.2 +/- 0.6, 0 out of 28 [0%]); and 50 microg/ml (1.2 +/- 0.6, 1 out of 16 [6%]; 1.1 +/- 0.6, 1 out of 27 [4%]). The response in healthy control subjects, autoantibody-negative relatives, and IDDM patients, respectively, against the proinsulin peptide fragment were as follows: 1 microg/ml (0.9 +/- 0.4, 1 out of 12 [8%]; 1.3 +/- 1.1, 4 out of 34 [11%]; 1.1 +/- 0.3, 2 out of 28 [7%]); 10 microg/ml (0.9 +/- 0.6, 1 out of 12 [8%]; 1.2 +/- 0.6, 3 out of 34 [9%] 1.4 +/- 1.7, 2 out of 28 [7%]); and 50 microg/ml (1.0 +/- 0.7, 1 out of 12 [8%]; 1.2 +/- 0.5, 2 out of 34 [6%]; 1.3 +/- 0.5, 2 out of 28 [7%]). Taken together with previous studies reporting relatively infrequent occurrences of autoantibodies to proinsulin, the role of immunity to this molecule in the pathogenesis of IDDM in humans remains unclear.
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PMID:Cellular immune responses against proinsulin: no evidence for enhanced reactivity in individuals with IDDM. 1033 5

Glutamic acid decarboxylase 65 (GAD65) is one of the major autoantigens in type 1 diabetes. We investigated whether there is variation in the processing of GAD65 epitopes between individuals with similar HLA backgrounds and whether the processing characteristics of certain immunogenic epitopes are different in distinct APC subpopulations. Using DR401-restricted T cell hybridomas specific for two immunogenic GAD65 epitopes (115-127 and 274-286), we demonstrate an epitope-specific presentation pattern in human B-lymphoblastoid cell lines (B-LCL). When pulsed with the GAD protein, some DRB1*0401-positive B-LCL, which presented GAD65 274-286 epitope efficiently, were unable to present the GAD65 115-127 epitope. However, all B-LCL presented synthetic peptides corresponding to either GAD epitope. In addition, when pulsed with human serum albumin, all cell lines gave equal stimulation of a DR4-restricted human serum albumin-specific T hybridoma. GAD65-transfected cell lines displayed the same presentation phenotype, showing that lack of the presentation of the 115-127 epitope was not due to inefficient uptake of the protein. Blood mononuclear adherent cells, B cells, or dendritic cells derived from the same individual displayed the same presentation pattern as observed in B cell lines, suggesting that the defect most likely is genetically determined. Therefore, individual differences in Ag processing may result in the presentation of distinct set of peptides derived from an autoantigen such as GAD65. This may be an important mechanism for the deviation of the immune response either into a regulatory pathway or into an inflammatory autoimmune reactivity.
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PMID:Differential presentation of glutamic acid decarboxylase 65 (GAD65) T cell epitopes among HLA-DRB1*0401-positive individuals. 1041 74

The major histocompatibility complex (MHC) genes play a significant role in the predisposition to insulin-dependent diabetes mellitus or type 1 diabetes. HLA-DQ8 (DQB1*0302, DQA 1*0301) genes have been shown to have the highest relative risk for human type 1 diabetes. To develop a "humanized" mouse model of diabetes, HLA-DQ8 was transgenically expressed in mice lacking endogenous class II genes. Since non-MHC background genes of the NOD influence the disease process, AP"/DQ8 mice were mated with the NOD strain and backcrossed to generate Abeta degree/DQ8/NOD mice. These mice have DQ8 as the sole MHC class II restriction element with NOD background genes at the N 2 generation. The DQ8 transgenic mice were used to identify T cell epitopes on glutamic acid decarboxylase (GAD 65), an important putative autoantigen in type 1 diabetes. The NOD background genes strongly influenced antigen processing, that is, different T cell epitopes were generated from the processing of GAD 65 in vivo in the Abeta degree/DQ8 and in the Abeta degree/DQ8/NOD mice.
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PMID:NOD background genes influence T cell responses to GAD 65 in HLA-DQ8 transgenic mice. 1042 75

Autoimmune (type 1) diabetes mellitus results from a progressive destruction of insulin secreting beta cells operated by T lymphocytes in pancreatic islets. Circulating autoreactive T cells to specific beta cell antigens are detected in patients with type 1 diabetes. To date, several beta cell autoantigens have been identified in this disease (GAD, IA-2, 38kD secretory protein, insulin, ICA69 etc.), however, it is possible that also other unidentified self molecules contribute to trigger beta cell autoimmunity. In this study we used the human insulinoma cell line CM as source of beta cell antigens to detect reactive T lymphocytes in patients with type 1 diabetes mellitus. This cell line has been previously shown to express a number of recognized beta cell antigens. Since the expression of several beta cell antigens is affected by glucose stimulation we tested two preparations of CM cells cultured under different conditions containing low (0.8 mM) and high glucose concentration (11 mM). T cell proliferation was measured using cells from 32 patients with type 1 diabetes (19 of recent onset and 13 at 3 to 22 months from diagnosis) and 27 age-matched control subjects. A significant increase in T cell proliferation to CM cells grown in high glucose conditions (11 mM) (p < 0.05) was found in type 1 diabetic patients compared to controls. No significant differences were observed when using CM cells cultured at the low glucose concentration. Furthermore, the response to both extracts of CM cells was independent of disease duration (p = 0.6 for both CM cells cultured at 0.8 and 11 mM glucose). These data indicate that T cell reactivity to homogenates of CM cells is detectable in patients with type 1 diabetes and suggest that this human insulinoma cell line is an interesting potential source of beta cell material for immunological studies of autoimmune diabetes.
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PMID:T cell reactivity to human insulinoma cell line (CM) antigens in patients with type 1 diabetes. 1043 97

Type I diabetes mellitus results from the autoimmune destruction of insulin producing beta cells in the pancreas. Certain viral infections, especially those caused by coxsackie B viruses and related enteroviruses, have been associated with the development of type I diabetes. The sequence homology between the coxsackie B4 virus nonstructural protein 2C (CVB4 p2C) and the major diabetes autoantigen glutamic acid decarboxylase (GAD(65)) provides a basis for the hypothesis of molecular mimicry. In this study, we investigated the prevalence of antibodies directed against nonstructural enterovirus proteins. In addition, a correlation of antibodies against CVB4 p2C and GAD(65) was studied in diabetes patients and in healthy controls. Antibody reactivity against CVB proteins was detected by immunoprecipitation of [(35)S]-methionine-labelled viral proteins and GAD(65) antibodies were measured in a quantitative radio-immunoassay. It was shown that antibodies raised against the nonstructural proteins of CVB4 are very common in the population and a high degree of heterotypic cross-reactivity exists between different enterovirus types. CVB4 p2C-specific antibodies were not only detectable in GAD(65) antibody-positive diabetes patients but also in GAD(65) antibody-negative healthy blood donors. Furthermore, GAD(65) antibodies could not be detected in p2C-positive subjects who had various enterovirus infections, indicating that an antibody response to CVB4 p2C does not necessarily induce a cross-reactive immune response against GAD(65). A correlation was not found between antibodies against GAD(65) and p2C.
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PMID:Analysis of antibody responses against coxsackie virus B4 protein 2C and the diabetes autoantigen GAD(65). 1045 65

It has been reported that there is a heterogeneity in the clinical course of Japanese patients with type 1 diabetes. To elucidate the associations of expression of autoantibodies to multiple islet antigens with age of onset and mode of diagnosis of diabetes in Japanese patients with type 1 diabetes, autoantibodies against the protein tyrosine phosphatase-like molecules ICA512 (IA-2) and phogrin (IA-2beta) (ICA512/phogrin-A), GAD (GADA), insulin (IAA), and islet cell cytoplasm (ICA) were determined in sera from 73 Japanese patients with type 1 diabetes obtained within 14 days of diagnosis. Patients were divided into groups based on the age of onset (</=10 years, n=24 and >10 years, n=49) or the mode of onset (abrupt onset, n=59 and urinary screening identified, n=14). Of 73 new-onset patients with type 1 diabetes, 43 (59%) and 32 (44%) had ICA512A and phogrin-A levels exceeding the 99th percentile of 184 normal control subjects, respectively. Forty-five patients (62%) were positive for either ICA512A or phogrin-A. The frequencies for other autoantibodies were 71% for GADA, 48% for IAA, and 62% for ICA. The frequency of ICA512/phogrin-A was significantly higher in patients with an age of onset less than 10 years (83%) than in patients aged >10 years (51%, P<0.01). The positivity of ICA512/phogrin-A was less in patients whose diabetes was diagnosed by the urine glucose screening test (21%, P<0.001) than in abrupt onset patients (71%). Combined analysis (>/=1 antibody) of GADA, IAA, and ICA512/phogrin-A detected 88% of abrupt onset and 93% of screening-positive patients vs. 70% and 29%, respectively, for ICA (P<0.0005). These results indicate that the expression of ICA512/phogrin-A and cytoplasmic ICA is less in patients identified by urinary glucose testing but indicate that with combined autoantibody testing 90% of patients can be identified independent of the mode of diagnosis.
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PMID:Autoantibodies to multiple islet autoantigens in patients with abrupt onset type 1 diabetes and diabetes diagnosed with urinary glucose screening. 1047 94


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