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)

Insulin-dependent diabetes mellitus (IDDM) susceptibility determinants are known to be associated with both HLA-DR3 and -DR4. We monitored the inheritance of HLA-DR alleles in 37 families in which IDDM affected one parent and at least one offspring in order to try to learn more about the modes of inheritance of IDDM determinants. Ninety-seven insulin-dependent diabetics whose parents did not have diabetes and 158 nondiabetics were used as control groups for estimates of DR allele frequencies in the overall diabetic and general populations. The proportion of diabetic parents who transmitted DR4 to diabetic offspring (78%) was significantly higher (P less than 0.001) than the gene frequency of DR4 in the overall diabetic population (43%). The proportion of nondiabetic parents who transmitted DR4 to diabetic offspring (22%) was not significantly different from the gene frequency of DR4 in the nondiabetic population (16%), but it was significantly lower (P less than 0.05) than the gene frequency in the overall IDDM population. These proportions suggest that inheritance of the DR4-associated IDDM susceptibility determinant is not recessive, because in recessive inheritance expression of a trait depends on each parent contributing a susceptibility determinant. The proportions of diabetic and nondiabetic parents who transmitted the DR allele associated with the susceptibility determinant would then equal one another. The transmission of predominantly DR4 from affected parents to affected offspring suggests that susceptibility to IDDM is inherited primarily via a single dose of a potent determinant associated with DR4, as in dominant inheritance. When DR3 was transmitted at all it was usually by the nondiabetic parent. Only 8% of diabetic parents transmitted DR3 but 35% of nondiabetic parents transmitted DR3. The proportion of nondiabetic parents who transmitted DR3 was similar to the gene frequency of DR3 in the overall diabetic population (29%), but it was significantly higher than the gene frequency of DR3 in the nondiabetic population (15%; P less than 0.005). The percentage of diabetic offspring with the genotype DR3DR4 (35%) was identical to the percentage of individuals in the overall IDDM population with this genotype (35%). Numerous population data indicate that the DR3DR4 genotype carries a higher relative risk for IDDM than any other genotype, which suggests synergism between the DR3- and DR4-associated determinants. The family data reported here support this synergism but suggest that the DR4-associated determinant can give substantial susceptibility independent of the DR3-associated determinant and that the DR3-associated determinant is often expressed as enhancing susceptibility in the presence of the dominant DR4- associated determinant.
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PMID:HLA-DR4 in insulin-dependent diabetic parents and their diabetic offspring: a clue to dominant inheritance. 348 37

The human major histocompatibility complex (MHC)-linked genes C2,BF,C4A,C4B occur in populations and segregate in families as single genetic units or complotypes. Analysis for significant three-point linkage disequilibrium between HLA-B, DR and complotype on normal caucasian chromosomes 6p yields about a dozen haplotypes that account for most of the known HLA-B/HLA-DR linkage disequilibrium pairs previously noted in normal caucasian populations. We refer to the HLA-B/DR/complotype sets with significant linkage disequilibrium as extended haplotypes since they often show limited variation at other MHC-linked loci. From the study of MHC haplotypes in 21-hydroxylase deficiency, C2 deficiency and type 1 diabetes, it is becoming apparent that it is extended haplotypes rather than their individual alleles that are markers for these MHC-associated diseases.
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PMID:Complement genes of the major histocompatibility complex (complotypes), extended haplotypes and disease markers. 349 6

Diabetes mellitus is a heterogeneous syndrome. Insulin-dependent type 1 diabetes is characterized by progressive deterioration of B-cells in the islets of Langerhans resulting in a fall in insulin secretion. According to recent studies, autoimmune mechanisms are the reason for the B-cell destruction. These mechanisms can be triggered by viral infections which result in expression of HLA-DR antigens in macrophages and possibly in B-cells of the islets. B-cells are destroyed by cytotoxic T-lymphocytes; plasma cells form islet cell antibodies. The autoimmune process probably starts months to years before clinical manifestation of the disease. A viral infection immediately before clinical manifestation may reactivate the autoimmune process and lead to overt diabetes. T-lymphocytes reject pancreatic B-cells in type 1 diabetics throughout life. Pilot studies using cyclosporin as immunosuppressive agent in newly diagnosed type 1 diabetics have demonstrated that after discontinuation of this treatment diabetics again became insulin-dependent. Type 2 diabetics are usually elderly and non-insulin-dependent; there is a predominant defect in insulin action on peripheral tissues but also a concomitant impairment of B-cell secretion. Fasting plasma insulin levels are normal or increased; fasting C-peptide concentrations may be used to distinguish this type of diabetes from type 1 diabetes. Plasma fasting C-peptide concentrations less than 300 pmol/l usually indicate type 1 diabetes and levels above 300 pmol/l type 2 diabetes. Classification of diabetics according to pathogenesis is important, since different therapeutic and preventive measures are necessary.
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PMID:[New findings on the pathogenesis of diabetes mellitus]. 351 24

From our studies in Caucasian families of HLA, complement, and glyoxalase alleles have developed the concepts of the complotype and the extended haplotype. complotypes are clusters of the four genes for complement proteins encoded within the MHC designated (in arbitrary order) by their BF, C2, C4A, and C4B alleles. They are inherited in families and occur in populations as functionally single genetic units and exhibit linkage disequilibrium with HLA-B and HLA-DR alleles which are complotype, rather than complement gene allele, specific. In Caucasians, there are 10-12 common sets of HLA-B, DR, complotype sets that show significant linkage disequilibrium. These haplotypes constitute 25-30% of all MHC haplotypes in Caucasians. Because there is evidence for relative fixity of alleles on these chromosomes to an unknown extent beyond the HLA-B-DR interval, they have been called extended MHC haplotypes. It appears likely that it is these extended haplotypes that provide most of the known linkage disequilibrium pairs previously reported for MHC alleles as well as many of the known MHC allele-disease associations. The most common extended haplotype [HLA-B8, DR3, SC01], when it carries GLO2, is increased in type I diabetes mellitus and probably a number of other diseases, including gluten-sensitive enteropathy and membranoproliferative glomerulonephritis. In the families with these disorders studied by us, this haplotype exhibits male segregation distortion, a feature displayed by t-mutants found in wild mouse populations. This feature constitutes an important selective advantage for the chromosome and may contribute to the accumulation of susceptibility mutations for a variety of diseases.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Complotypes, extended haplotypes, male segregation distortion, and disease markers. 351 38

Type I diabetes mellitus appears to result from an insidious immunologic destruction of pancreatic beta-cells in genetically susceptible persons exposed to one or a series of environmental insults. This genetic susceptibility is related to alleles located on the sixth chromosome in the HLA-DR or an adjacent region. With superimposition of a viral or other environmental triggering event, cell-and antibody-mediated events are activated that lead to the specific autorejection of beta-cells and consequent insulin deficiency. Immunosuppressive strategies to impede or halt complete destruction of beta-cells, using cyclosporine, have already been initiated in both animals and humans with diabetes mellitus. Because of the potential toxicity of all current immunosuppressive regimens, such therapies cannot, at this time, be considered for wide-scale use in persons with type I diabetes. Reported inductions, however, of insulin independence in patients with newly diagnosed type I diabetes using cyclosporine or other agents underscore the role of the immune system in the pathogenesis of the disease and highlight the need to develop safer, more specific immunomodulation designed to avoid complete beta-cell destruction.
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PMID:The role of immunotherapy in type I diabetes mellitus. 355 59

In order to assess interaction between HLA and Gm for susceptibility to IDDM, the families of 155 IDDM probands were typed for HLA class I, II, III antigens and 16 Gm allotypes (including G2m23). Haplotypes were obtained for both systems. Individuals bearing the equivocal haplotype Gm (formula; see text) were excluded. The frequencies of the 6 Gm haplotypes detected were comparable in IDDM patients, sibling controls and unrelated controls. The number of Gm haplotypes was compatible with random segregation whether or not the HLA genotype was taken into account. However, analysis of the HLA-DR allelic combinations showed an increase of the uncommon haplotype Gm (formula; see text) in IDDM patients bearing DR3 in the absence of DR4 (Gm (formula; see text) phenotype frequency 43% vs 24% in other allelic combinations, p less than 0.04). When 21 diabetic and 154 non diabetic siblings of the probands were compared, the combined presence of DR3/ non 4 and Gm (formula; see text) was observed in 7 (33%) affected and 11 (7%) unaffected siblings (p less than 0.001), conferring a relative risk of 6.4 to siblings who bear both markers. All DR3/non 4 positive affected siblings (7/7) also carried Gm (formula; see text) compared with 27% (11/41) of unaffected siblings (p less than 0.001). This result suggests, that in spite of the absence of segregation distortion, interaction between Gm and HLA gene products may play a role in the familial penetrance of IDDM.
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PMID:A Gm haplotype study in relation with HLA-DR in 155 insulin-dependent diabetic patients and their affected and non affected siblings. 366 50

In most of the cases, once a given endocrine gland is involved, the corresponding specific autoantibody may be detected; for example, anti-islet cell antibodies are produced within the first few years, after onset of symptoms in insulin-dependent diabetes (DID). Accompanying autoantibodies are quite frequently found in the patient himself. In Schmidt's syndrome (thyroid and adrenal glands are involved and associated to IDD in 30% of the cases) thyroid microsomal antibodies are found in 38% of the cases, thyroglobulin antibodies in 11% of the cases, islet-cell antibodies in 7% of the cases and steroid cell antibodies in 17% of the cases. Associations are also possible in patient family members. Aberrant expression of HLA-DR molecules at the membrane of follicular thyroid cells (as of any other endocrine gland), following a viral aggression, could well account for the endocrinopathy combinations, but alternative mechanisms should be discussed.
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PMID:[Autoimmune polyendocrinopathies. Pathogenic hypotheses]. 382 97

No significant differences could be found in the HLA-DR antigen frequency of two groups of patients with insulin dependent diabetes mellitus (IDDM). One group consisted of 49 patients with proliferative diabetic retinopathy and the other group of 31 patients with no ophthalmoscopic evidence of diabetic retinopathy.
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PMID:HLA-DR antigen association with proliferative diabetic retinopathy. 386 Apr 83

In a prospective screening program for type I diabetes mellitus, we identified a unique family in which several members (mother and three siblings) expressed an unusual set of HLA-DR alleles (DR2+, DR3/4-) and were in different phases of immunologically mediated islet beta cell dysfunction. Immunologic and/or clinical manifestations of type I diabetes were absent in all siblings not sharing both HLA haplotypes in common with the proband. This article illustrates: the clinical utility of prospective family screening for predictive markers, such as islet cell antibodies, progressive autoimmune beta cell destruction can occur in the absence of the "high-risk" alleles HLA-DR3 and DR4, and HLA identity with the proband, rather than specific HLA alleles, i.e., presence of DR3, DR4 and absence of DR2, is an essential factor.
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PMID:Progressive autoimmune beta cell insufficiency: occurrence in the absence of high-risk HLA alleles DR3, DR4. 387 22

Four patients with type 1 diabetes mellitus received segmental pancreatic grafts. The donors were HLA-identical twins in three patients and an HLA-identical sibling in one. Each patient had normal glucose metabolism in the posttransplantation period but impaired graft function developed after 6 to 12 weeks. Complete loss of function developed in three patients. The fourth patient received immunosuppressive therapy but continues to require a low dose of insulin 15 months following transplantation. Pancreatic graft biopsy at the time of declining graft function in three patients revealed a mononuclear cell infiltrate centered upon islets consisting of variable numbers of T11 (pan T), OKT8 (suppressor-killer), OKT9 (transferrin receptor), OKT10 (activated), and HLA-DR-reactive mononuclear cells, as well as 63D3 and OKM1 reactive monocytes. Biopsies obtained following loss of graft function revealed resolution of the inflammatory process and selective destruction of all islet beta-cells in two patients, whereas graft biopsy in one patient demonstrated a mononuclear cell infiltrate in islets containing demonstrable beta-cells but no infiltrate in islets without beta-cells. Following immunosuppressive therapy the fourth patient showed resolution of the insulitis and destruction of beta-cells in 70% of the islets. The variable numbers of beta-cells observed in the remaining islets likely account for the relatively low amount of exogenous insulin required by this patient. There was no immunohistologic evidence of humoral mediated immune reaction in any of the biopsies. It is postulated that selective beta-cell destruction was a consequence of cell-mediated immunity leading to recurrent diabetes mellitus.
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PMID:Recurrent diabetes mellitus in the pancreas iso- and allograft. A light and electron microscopic and immunohistochemical analysis of four cases. 389 93


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