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- Andersson Svärd, Agnes
(författare)
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Att forska om typ 1 diabetes
- 2016
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Ingår i: Diabetesnytt Blekinge Diabetesförening Medlemstidning. ; :3, s. 4-5
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 2. |
- Andersson Svärd, Agnes, et al.
(författare)
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Characterization of plasma lipidomics in adolescent subjects with increased risk for type 1 diabetes in the DiPiS cohort
- 2020
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Ingår i: Metabolomics. - : Springer Science and Business Media LLC. - 1573-3882 .- 1573-3890. ; 16:10
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Type 1 diabetes (T1D) is caused by the destruction of pancreatic islet beta cells resulting in total loss of insulin production. Recent studies have suggested that the destruction may be interrelated to plasma lipids.OBJECTIVES: Specific lipids have previously been shown to be decreased in children who develop T1D before four years of age. Disturbances of plasma lipids prior to clinical diagnosis of diabetes, if true, may provide a novel way to improve prediction, and monitor disease progression.METHODS: A lipidomic approach was utilized to analyze plasma from 67 healthy adolescent subjects (10-15 years of age) with or without islet autoantibodies but all with increased genetic risk for T1D. The study subjects were enrolled at birth in the Diabetes Prediction in Skåne (DiPiS) study and after 10-15 years of follow-up we performed the present cross-sectional analysis. HLA-DRB345, -DRB1, -DQA1, -DQB1, -DPA1 and -DPB1 genotypes were determined using next generation sequencing. Lipidomic profiles were determined using ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry. Lipidomics data were analyzed according to genotype.RESULTS: Variation in levels of several specific phospholipid species were related to level of autoimmunity but not development of T1D. Five glycosylated ceramides were increased in insulin autoantibody (IAA) positive adolescent subjects compared to adolescent subjects without this autoantibody. Additionally, HLA genotypes seemed to influence levels of long chain triacylglycerol (TG).CONCLUSION: Lipidomic profiling of adolescent subjects in high risk of T1D may improve sub-phenotyping in this high risk population.
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| 3. |
- Andersson Svärd, Agnes, et al.
(författare)
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Decreased HLA-DQ expression on peripheral blood cells in children with varying number of beta cell autoantibodies
- 2020
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Ingår i: Journal of Translational Autoimmunity. - : Elsevier BV. - 2589-9090. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- The risk for type 1 diabetes is strongly associated with HLA-DQ and the appearance of beta cell autoantibodies against either insulin, glutamate decarboxylase (GAD65), insulinoma-associated protein-2 (IA-2), or zinc transporter 8 (ZnT8). Prolonged exposure to autoantibodies may be related to T cell exhaustion known to occur in chronic infections or autoimmune disorders. It was hypothesized that autoantibody exposure may affect HLA-DQ expression on peripheral blood cells and thereby contribute to T cell exhaustion thought to be associated with the pathogenesis of type 1 diabetes. The aim of this study was to determine whether autoantibody exposure as an expression of autoimmunity burden was related to peripheral blood cell HLA-DQ cell surface expression in either 1) a cross-sectional analysis or 2) cumulative as area under the trajectory of autoantibodies during long term follow-up in the Diabetes Prediction in Skåne (DiPiS) study. Children (n = 67), aged 10-15 years were analyzed for complete blood count, HLA-DQ cell surface median fluorescence intensity (MFI), autoantibody frequency, and HLA genotypes by Next Generation Sequencing. Decreased HLA-DQ cell surface MFI with an increasing number of autoantibodies was observed in CD16+, CD14+CD16-, CD4+ and CD8+ cells but not in CD19+ cells and neutrophils. HLA-DQ cell surface MFI was associated with HLA-DQ2/8 in CD4+ T cells, marginally in CD14+CD16- monocytes and CD8+ T cells. These associations appeared to be related to autoimmunity burden. The results suggest that HLA-DQ cell surface expression was related to HLA and autoimmunity burden.
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| 7. |
- Andersson Svärd, Agnes, et al.
(författare)
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Possible Relationship between the HLA-DRA1 Intron Haplotype of Three Single-Nucleotide Polymorphisms in Intron 1 of the HLA-DRA1 Gene and Autoantibodies in Children at Increased Genetic Risk for Autoimmune Type 1 Diabetes
- 2022
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Ingår i: ImmunoHorizons. - : The American Association of Immunologists. - 2573-7732. ; 6:8, s. 614-629
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Tidskriftsartikel (refereegranskat)abstract
- Recently, a haplotype of three single-nucleotide polymorphisms (tri-SNP) in intron 1 of the HLA-DRA1 gene was found to be strongly associated with type 1 diabetes risk in HLA-DR3/3 individuals. The tri-SNP reportedly function as “expression quantitative trait loci,” modulating HLA-DR and -DQ expression. The aim was to investigate HLA-DRA1 tri-SNPs in relation to extended HLA class II haplotypes and human peripheral blood cell HLA-DQ cell-surface median fluorescence intensity (MFI), the first-appearing islet autoantibody, and autoimmunity burden. A total of 67 healthy subjects (10–15 y) at increased HLA risk for type 1 diabetes and with (n = 54) or without (n = 13) islet autoantibodies were followed longitudinally in the Diabetes Prediction in Skåne study. Among four tri-SNPs, AGG (n = 67), GCA (n = 47), ACG (n = 11), and ACA (n = 9), HLA-DQ cell-surface MFI on CD4+ T cells was lower in AGG than GCA (p = 0.030) subjects. Cumulative autoimmunity burden was associated with reduced HLA-DQ cell-surface MFI in AGG compared with GCA in CD16+ cells (p = 0.0013), CD4+ T cells (p = 0.0018), and CD8+ T cells (p = 0.016). The results suggest that HLA-DRA1 tri-SNPs may be related to HLA-DQ cell-surface expression and autoimmunity burden.
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| 8. |
- Aydemir, O, et al.
(författare)
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Genetic Variation Within the HLA-DRA1 Gene Modulates Susceptibility to Type 1 Diabetes in HLA-DR3 Homozygotes
- 2019
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Ingår i: Diabetes. - : American Diabetes Association. - 1939-327X .- 0012-1797. ; 68:7, s. 1523-1527
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Tidskriftsartikel (refereegranskat)abstract
- Type 1 diabetes (T1D) involves the interaction of multiple gene variants, environmental factors, and immunoregulatory dysfunction. Major T1D genetic risk loci encode HLA-DR and -DQ. Genetic heterogeneity and linkage disequilibrium in the highly polymorphic HLA region confound attempts to identify additional T1D susceptibility loci. To minimize HLA heterogeneity, T1D patients (N = 365) and control subjects (N = 668) homozygous for the HLA-DR3 high-risk haplotype were selected from multiple large T1D studies and examined to identify new T1D susceptibility loci using molecular inversion probe sequencing technology. We report that risk for T1D in HLA-DR3 homozygotes is increased significantly by a previously unreported haplotype of three single nucleotide polymorphisms (SNPs) within the first intron of HLA-DRA1. The homozygous risk haplotype has an odds ratio of 4.65 relative to the protective homozygous haplotype in our sample. Individually, these SNPs reportedly function as “expression quantitative trait loci,” modulating HLA-DR and -DQ expression. From our analysis of available data, we conclude that the tri-SNP haplotype within HLA-DRA1 may modulate class II expression, suggesting that increased T1D risk could be attributable to regulated expression of class II genes. These findings could help clarify the role of HLA in T1D susceptibility and improve diabetes risk assessment, particularly in high-risk HLA-DR3 homozygous individuals.
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| 9. |
- Aydemir, Özkan, et al.
(författare)
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Polymorphisms in Intron 1 of HLA-DRA Differentially Associate with Type 1 Diabetes and Celiac Disease and Implicate Involvement of Complement System Genes C4A and C4B
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Ingår i: eLife. - 2050-084X.
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Tidskriftsartikel (refereegranskat)abstract
- Polymorphisms in genes in the human leukocyte antigen (HLA) class II region comprise the most important inherited risk factors for many autoimmune diseases including type 1 diabetes (T1D) and celiac disease (CD): both diseases are positively associated with the HLA- DR3 haplotype (DRB1*03:01-DQA1*05:01-DQB1*02:01). Studies of two different populations have recently documented that T1D susceptibility in HLA-DR3 homozygous individuals isstratified by a haplotype consisting of three single nucleotide polymorphisms (“tri-SNP”) in intron 1 of the HLA-DRA gene. In this study, we use a large cohort from the longitudinal “The Environmental Determinants of Diabetes in the Young” (TEDDY) study to further refine the tri-SNP association with T1D and with autoantibody-defined T1D endotypes. We found that the tri-SNP association is primarily in subjects whose first-appearing T1D autoantibody is to insulin. In addition, we discovered that the tri-SNP is also associated with celiac disease (CD), and that the particular tri-SNP haplotype (“101”) that is negatively associated with T1D risk is positively associated with risk for CD. The opposite effect of the tri-SNP haplotype on two DR3-associated diseases can enhance and refine current models of disease prediction based on genetic risk. Finally, we investigated possible functional differences between the individuals carrying high and low-risk tri-SNP haplotypes, and found that differences in complement system genes C4A and C4B may underlie the observed divergence in disease risk.
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| 10. |
- Lindbladh, Ida, et al.
(författare)
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Autoimmune (type 1) diabetes
- 2019. - 6
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Ingår i: The Autoimmune Diseases. - 9780128121023 - 9780128122426 ; , s. 769-787
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Bokkapitel (refereegranskat)abstract
- Autoimmune (type 1) diabetes mellitus is a chronic disease without a cure. It affects primarily young people but may be diagnosed at any age. Strong genetic susceptibility characterizes the most common form of autoimmune diabetes in children younger than 18 years of age. Autoimmune diabetes is generally assumed to be hereditary, although the majority of patients do not have a family history of autoimmune diabetes. The etiology is not fully understood. However, the genetic susceptibility is strongly associated with genetic factors within the human leukocyte antigen (HLA) complex on chromosome 6. The role of HLA is associated with the development of islet autoimmunity, a stage marked by the appearance of autoantibodies against islet beta-cell proteins. Non-HLA genetic factors contribute to the risk for a first appearing islet autoantibody. Environmental etiological factors include candidate virus, but how a virus infection may yield islet autoimmunity remains to be clarified. The pathogenesis of autoimmune diabetes is characterized by a complex and prolonged autoimmune prodrome (prediabetic) phase which may last for months to years. The asymptomatic phases, Stage I (two or more autoantibodies and normoglycemia) and Stage II (two or more autoantibodies and dysglycemia), are marked by autoantibodies against either insulin (IAA), glutamic acid decarboxylase (GADA), islet antigen-2 (IA-2A), zinc transporter 8 alone, or in combination. In the third and symptomatic stage (Stage III) of disease, mononuclear cell infiltration has been detected in many but not in all patients, a beta-cell loss is significant and dysglycemia and classic symptoms of hyperglycemia develop. Lifelong insulin replacement therapy is still the only treatment. The identification of environmental determinants that trigger either IAA first or GADA first remains a major challenge to the understanding of the etiology and pathogenesis of autoimmune diabetes.
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