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Islet Autoimmunity (islet + autoimmunity)
Selected AbstractsIslet autoimmunity and genetic mutations in Chinese subjects initially thought to have Type 1B diabetesDIABETIC MEDICINE, Issue 1 2006D. Zhang Abstract Aims To explore the contribution of islet autoimmunity and genetic mutations in Chinese patients initially thought to have Type 1B diabetes. Methods A group of 33 Chinese patients with newly diagnosed Type 1B diabetes, were identified by the absence of autoantibodies to glutamic acid decarboxylase (GAD), IA-2, insulin, thyroid globulin or thyroid peroxidase, or high-risk HLA-DQ haplotypes. The cohort was further characterized by measurement of autoantibodies to carboxypeptidase H (CPH) and SOX13 using radioligand assays, and testing for genetic mutations associated with MODY3/MODY6 and mitochondrial diabetes. Mutations of HNF-1, (MODY3) and neuroD1/,2 (MODY6) genes were screened using the single-strand conformation polymorphism (SSCP) technique and sequencing. Mitochondrial DNA mutations were analysed with polymerase chain reaction,restriction fragment length polymorphism (PCR-RFLP). Results Within the cohort, we found one patient with a novel mutation, R321H (CGC,CAC) in exon 5 of the HNF-1, gene, one with ND1 mt3316 G,A mutation in mitochondrial DNA, five with Ala45Thr polymorphisms in the neuroD1/,2 gene, and two patients with autoantibodies to SOX13. Conclusions Some of the Chinese patients originally thought to have Type 1B diabetes do have other evidence of islet autoimmunity and genetic mutations involved in the underlying aetiology. This suggests that more rigorous screening for these conditions is needed before classifying subjects as having Type 1B diabetes. [source] Environmental triggers of type 1 diabetesJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 3 2001JJ Couper Abstract: High risk HLA class II alleles account for 40% of the genetic susceptibility to type 1 diabetes in Caucasians, but the majority of the genetically predisposed do not develop the disease. This supports some environmental modification of the autoimmune destruction of , cells that precedes type 1 diabetes. Identical twin studies and geographical variation in incidence also argue for a critical role of environmental factors. Attention has been directed to the possible harmful effect of cow's milk protein (or protective effect of breast-feeding) and enteric infections in early life. Natural history studies that follow children at increased risk of type 1 diabetes provide the best opportunity to study environmental triggers. The Australian Baby Diab Study has followed approximately 500 babies from birth who have a first-degree relative with type 1 diabetes. No prospective association between duration of breast-feeding or introduction of cow's milk and the development of islet autoimmunity was found. The same Australian cohort demonstrated a relationship between rotavirus infection and the first appearance or increase in islet antibodies. Enteroviral infection is seen more frequently in prediabetic children and prior to the onset of islet autoimmunity in Finnish cohorts. Environmental factors may interact. Breast milk protects against enteric infections; enteric infections in turn could increase immunity to dietary antigens by increasing intestinal permeability. It is also possible that an alteration in gut mucosal immune function in genetically susceptible individuals underlies any effect of dietary or viral proteins on the development of islet autoimmunity in early life. [source] An exploration of Glo-3A antibody levels in children at increased risk for type 1 diabetes mellitusPEDIATRIC DIABETES, Issue 8 2009M Simpson Aims: To determine whether Glo-3A, (formerly referred to as homologue of Glb1 or Glb1) antibodies are associated with islet autoimmunity (IA) in children at increased risk for type 1 diabetes (T1D) and to investigate their relation with environmental correlates of T1D. Methods: We selected a sample from the Diabetes Autoimmunity Study in the Young (DAISY), a prospective study of children at increased risk for T1D. Cases were positive for insulin, glutamic acid decarboxylase (GAD), or insulinoma-associated antigen-2 (IA-2) autoantibodies on two consecutive visits and either diagnosed with diabetes mellitus or still autoantibody positive when selected. Controls were from the same increased risk group, of similar age as the cases but negative for autoantibodies. Sera from 91 IA cases and 82 controls were analyzed in a blinded manner for immunoglobulin G (IgG) antibodies to Glo-3A by ELISA. Results: Adjusting for family history of T1D and human leukocyte antigen (HLA)-DR4 positivity, Glo-3A antibodies were not associated with IA case status (OR: 1.01, 95% CI: 0.99,1.03). Adjusting for age, family history of T1D, and HLA-DR4 positivity, Glo-3A antibody levels were inversely associated with breast-feeding duration (beta = ,0.08, p = 0.001) and directly associated with current intake of foods containing gluten (beta = 0.24, p = 0.007) in IA cases but not in controls. Zonulin, a biomarker of gut permeability, was directly associated with Glo-3A antibody levels in cases (beta = 0.73, p = 0.003) but not in controls. Conclusion: Differing correlates of Glo-3A antibodies in IA cases and controls suggest an underlying difference in mucosal immune response. [source] | ||||||||||