| 1. |
- Brorsson, Caroline, et al.
(författare)
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A non-synonymous variant in SLC30A8 is not associated with type 1 diabetes in the Danish population
- 2008
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Ingår i: Molecular Genetics and Metabolism. - : Elsevier BV. - 1096-7192. ; 94:3, s. 386-388
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association scans in type 2 diabetes (T2D) have identified a risk variant, rs13266634 (Arg325Trp), in SLC30A8 on chromosome 8. SLC30A8 encodes a beta-cell specific zinc-ion transporter and rs13266634 has been shown to affect insulin secretion. Recently, autoantibodies for Slc30A8 with high predictive value were demonstrated in individuals with type 1 diabetes (T1 D), making this gene an interesting T1 D candidate gene. We genotyped rs13266634 in 3008 cases and controls and 246 families from Denmark. Association to T1 D could not be demonstrated.
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| 2. |
- Brorsson, Caroline, et al.
(författare)
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Correlations between islet autoantibody specificity and the SLC30A8 genotype with HLA-DQB1 and metabolic control in new onset type 1 diabetes
- 2011
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Ingår i: Autoimmunity. - : Taylor & Francis. - 0891-6934 .- 1607-842X. ; 44:2, s. 107-114
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Tidskriftsartikel (refereegranskat)abstract
- We hypothesised that the correlation between autoantibody specificity for the ZnT8 Arg325Trp isoforms and the type 2 diabetes-associated rs13266634 may affect beta-cell function at type 1 diabetes (T ID) onset. To study this, we tested 482 newly diagnosed diabetic probands and 478 healthy siblings from the Danish population-based T1D registry for autoantibodies to ZnT8 (ZnT8A) in addition to GAD65 and IA-2. The prevalence and titres of autoantibodies were correlated with genotypes for rs13266634 and HLA-DQB1, age at diagnosis (AAD) and insulin dose-adjusted HbA1c (IDAA1c), as a proxy for residual beta-cell function. We replicated the correlation between rs13266634 genotypes and specificity for the ZnT8-Argenine (ZnT8R) and ZnT8-Tryptophan (ZnT8W) isoforms previously reported. ZnT8A overlapped substantially with autoantibodies to glutamate decarboxylase 65 (GADA) and IA-2 (IA-2A) and correlated significantly with IA-2A prevalence (p < 2e-16). No effect on IDAA1c was demonstrated for ZnT8A or rs13266634. We found a correlation between ZnT8R positivity and HLA-DQB1*0302 genotypes (p = 0.016), which has not been shown previously. Furthermore, significantly lower ZnT8R and GADA prevalence and titres was found among probands with AAD < 5 years (prevalence: p = 0.004 and p = 0.0001; titres: p = 0.002 and p = 0.001, respectively). The same trend was observed for IA-2A and ZnT8W; however, the difference was non-significant. Our study confirms ZnT8 as a major target for autoantibodies at disease onset in our Danish T1D cohort of children and adolescents, and we have further characterised the relationship between autoantibody specificity for the ZnT8 Arg325Trp epitopes and rs13266634 in relation to established autoantibodies, AAD, measures of beta-cell function and HLA-DQB1 genotypes in T1D.
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| 3. |
- Brorsson, Caroline, et al.
(författare)
-
Correlations between islet autoantibody specificity and the SLC30A8 genotype with HLA-DQB1 and metabolic control in new onset type 1 diabetes
- 2011
-
Ingår i: Autoimmunity. - : Informa UK Limited. - 0891-6934 .- 1607-842X. ; 44:2, s. 107-114
-
Tidskriftsartikel (refereegranskat)abstract
- We hypothesised that the correlation between autoantibody specificity for the ZnT8 Arg325Trp isoforms and the type 2 diabetes-associated rs13266634 may affect beta-cell function at type 1 diabetes (T ID) onset. To study this, we tested 482 newly diagnosed diabetic probands and 478 healthy siblings from the Danish population-based T1D registry for autoantibodies to ZnT8 (ZnT8A) in addition to GAD65 and IA-2. The prevalence and titres of autoantibodies were correlated with genotypes for rs13266634 and HLA-DQB1, age at diagnosis (AAD) and insulin dose-adjusted HbA1c (IDAA1c), as a proxy for residual beta-cell function. We replicated the correlation between rs13266634 genotypes and specificity for the ZnT8-Argenine (ZnT8R) and ZnT8-Tryptophan (ZnT8W) isoforms previously reported. ZnT8A overlapped substantially with autoantibodies to glutamate decarboxylase 65 (GADA) and IA-2 (IA-2A) and correlated significantly with IA-2A prevalence (p < 2e-16). No effect on IDAA1c was demonstrated for ZnT8A or rs13266634. We found a correlation between ZnT8R positivity and HLA-DQB1*0302 genotypes (p = 0.016), which has not been shown previously. Furthermore, significantly lower ZnT8R and GADA prevalence and titres was found among probands with AAD < 5 years (prevalence: p = 0.004 and p = 0.0001; titres: p = 0.002 and p = 0.001, respectively). The same trend was observed for IA-2A and ZnT8W; however, the difference was non-significant. Our study confirms ZnT8 as a major target for autoantibodies at disease onset in our Danish T1D cohort of children and adolescents, and we have further characterised the relationship between autoantibody specificity for the ZnT8 Arg325Trp epitopes and rs13266634 in relation to established autoantibodies, AAD, measures of beta-cell function and HLA-DQB1 genotypes in T1D.
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| 4. |
- Eising, Stefanie, et al.
(författare)
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Danish children born with glutamic acid decarboxylase-65 and islet antigen-2 autoantibodies at birth had an increased risk to develop type 1 diabetes
- 2011
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Ingår i: European Journal of Endocrinology. - 1479-683X. ; 164:2, s. 247-252
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Tidskriftsartikel (refereegranskat)abstract
- Objective: A large, population-based case-control cohort was used to test the hypothesis that glutamic acid decarboxylase-65 (GAD65) and islet antigen-2 autoantibodies (IA-2A) at birth predict type 1 diabetes. Design and methods: The design was an individually matched case-control study of all Danish type 1 diabetes patients born between 1981 and 2002 and diagnosed before May 1 2004 (median age at diagnosis was 8.8 years). Dried blood spot samples collected 5 days after birth in the 1981-2002 birth cohorts and stored at -25 degrees C were identified from 2023 patients and from two matched controls (n=4042). Birth data and information on parental age and diabetes were obtained from Danish registers. GAD65A and IA-2A were determined in a radiobinding assay. HLA-DQB1 alleles were analyzed by PCR using time-resolved fluorescence. Results: GAD65A and IA-2A were found in 70/2023 (3.5%) patients compared to 21/4042 (0.5%) controls resulting in a hazard ratio (HR) of 7.49 (P<0.0001). The HR decreased to 4.55 but remained significant (P<0.0003) after controlling for parental diabetes and HLA-DQB1 alleles. Conditional logistic regression analysis showed a HR of 2.55 (P<0.0001) for every tenfold increase in the levels of GAD65A and IA-2A. This HR decreased to 1.93 but remained significant (P<0.001) after controlling for parental diabetes and HLA-DQB1 alleles. Conclusion: These data suggest that GAD65A and IA-2A positivity at birth are associated with an increased risk of developing type 1 diabetes in Danish children diagnosed between 1981 and 2004. European Journal of Endocrinology 164 247-252
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| 5. |
- Eising, Stefanie, et al.
(författare)
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Type 1 diabetes risk analysis on dried blood spot samples from population-based newborns: design and feasibility of an unselected case-control study
- 2007
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Ingår i: Paediatric and Perinatal Epidemiology. - : Wiley. - 0269-5022 .- 1365-3016. ; 21:6, s. 507-517
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Tidskriftsartikel (refereegranskat)abstract
- Development of type 1 diabetes mellitus (T1D) may be triggered pre- or perinatally by multiple factors. Identifying new predisposing T1D markers or combinations of markers in a large, well-characterised case-control collection may be important for future T1D prevention. The present work describes the design and feasibility of a large and unselected case-control study, which will define and evaluate prediction criteria for T1D at the time of birth. Danish registries (Biological Specimen Bank for Neonatal Screening, and the National Discharge Registry) made it possible to identify and collect dried blood spots (DBS) from newborns who later developed T1D (cases) born 1981-2002. DBS samples from 2086 cases and two matching control subjects per case were analysed for genetic and immune factors that are associated with T1D: (a) candidate genes (HLA, INS and CTLA4), (b) cytokines and inflammatory markers, (c) islet auto-antibodies (GAD65A, IA-2A). The objective of the study was to define reliable prediction tools for T1D using samples available at the time of birth. In a unique approach, the study linked a large unselected and population-based sample resource to well-ascertained clinical databases and advanced technology. It combined genetic, immunological and demographic data to develop prediction algorithms. It also provided a resource for future studies in which new genetic markers can be included as they are identified.
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| 6. |
- Svensson, Jannet, et al.
(författare)
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Few differences in cytokines between patients newly diagnosed with type 1 diabetes and their healthy siblings
- 2012
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Ingår i: Human Immunology. - : Elsevier BV. - 0198-8859. ; 73:11, s. 1116-1126
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Tidskriftsartikel (refereegranskat)abstract
- The cause of the worldwide increase in type 1 diabetes (T1D) is largely unknown. T cells are thought to play a role in disease progression. In contemporary research over the last decade, age- and gender-specific serum levels as well as changes of Th1 and Th2-related cytokines are not well described. From a population-based register of children diagnosed from 1997 to 2005 this study explores eight different cytokines at time of diagnosis. Only TGF-beta and IL-18 showed higher levels in patients compared to siblings in an adjusted model (p < 0.01): whereas the other seven cytokines were not significantly different. IL-1 beta, IL-18, IL-12, IL-10 and IL-4 were significantly higher among the youngest children and males had significantly lower levels of IL-10 and IL-12 but higher levels of TNF-alpha. During the nine-year study all of the cytokines increased except TGF-beta, which showed a slight decrease over time. The cytokine levels tended to be highest during summer and were most pronounced for IL-1 beta and TNF-alpha. In conclusion, serum levels of known beta-cell cytotoxic cytokines were indifferent in patients and siblings, while gender, age and season appear to exert some influence on the serum level and need to be explored further. The influence of time on systemic levels cannot be ignored and may reflect decay or environmental impact on the immune system. (C) 2012 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.
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| 7. |
- Svensson, Jannet, et al.
(författare)
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High levels of immunoglobulin E and a continuous increase in immunoglobulin G and immunoglobulin M by age in children with newly diagnosed type 1 diabetes
- 2012
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Ingår i: Human Immunology. - : Elsevier BV. - 0198-8859. ; 73:1, s. 17-25
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Tidskriftsartikel (refereegranskat)abstract
- The incidence of type 1 diabetes (T1D) is increasing, either because of environmental factors accelerating onset of the disease or because of inducement of autoimmune diabetes in children who previously were at lower risk. High levels of immunoglobulin (Ig), specifically, IgM and IgA, and a low level of IgG were reported in adult patients; however no studies have analyzed the increasing incidence in relation to Ig levels. Our aim was to describe Ig in children newly diagnosed with diabetes and in their healthy siblings. Children with T1D expressed significantly lower IgG (p < 0.01) and higher IgA levels (p = 0.045), whereas no differences in IgE or IgM (p > 0.5) levels were found. Age-specific levels were unchanged over a 9-year period. In patients and siblings IgG. IgA and IgE increased by age (p < 0.001); which was in contrast to IgM (p > 0.05). The continued increase in IgG levels by age indicates that adult levels are reached later than in previously studied cohorts, thereby indicating a slower maturation of the immune system. (C) 2012 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.
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