| 1. |
- 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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| 2. |
- Barcenilla, Hugo, et al.
(författare)
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Mass Cytometry Identifies Distinct Subsets of Regulatory T Cells and Natural Killer Cells Associated With High Risk for Type 1 Diabetes
- 2019
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Ingår i: Frontiers in Immunology. - : FRONTIERS MEDIA SA. - 1664-3224. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Type 1 diabetes (T1D) is characterized by autoimmune destruction of insulin producing beta-cells. The time from onset of islet autoimmunity to manifest clinical disease can vary widely in length, and it is fairly uncharacterized both clinically and immunologically. In the current study, peripheral blood mononuclear cells from autoantibody-positive children with high risk for T1D, and from age-matched healthy individuals, were analyzed by mass cytometry using a panel of 32 antibodies. Surface markers were chosen to identify multiple cell types including T, B, NK, monocytes, and DC, and antibodies specific for identification of differentiation, activation and functional markers were also included in the panel. By applying dimensional reduction and computational unsupervised clustering approaches, we delineated in an unbiased fashion 132 phenotypically distinct subsets within the major immune cell populations. We were able to identify an effector memory Treg subset expressing HLA-DR, CCR4, CCR6, CXCR3, and GATA3 that was increased in the high-risk group. In addition, two subsets of NK cells defined by CD16(+) CD8(+) CXCR3(+) and CD16(+) CD8(+) CXCR3(+) CD11c(+) were also higher in the same subjects. High-risk individuals did not show impaired glucose tolerance at the time of sampling, suggesting that the changes observed were not the result of metabolic imbalance, and might be potential biomarkers predictive of T1D.
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| 3. |
- Beam, Craig A., et al.
(författare)
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GAD vaccine reduces insulin loss in recently diagnosed type 1 diabetes: findings from a Bayesian meta-analysis
- 2017
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Ingår i: Diabetologia. - : SPRINGER. - 0012-186X .- 1432-0428. ; 60:1, s. 43-49
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Tidskriftsartikel (refereegranskat)abstract
- GAD is a major target of the autoimmune response that occurs in type 1 diabetes mellitus. Randomised controlled clinical trials of a GAD + alum vaccine in human participants have so far given conflicting results. In this study, we sought to see whether a clearer answer to the question of whether GAD65 has an effect on C-peptide could be reached by combining individual-level data from the randomised controlled trials using Bayesian meta-analysis to estimate the probability of a positive biological effect (a reduction in C-peptide loss compared with placebo approximately 1 year after the GAD vaccine). We estimate that there is a 98% probability that 20 mu g GAD with alum administered twice yields a positive biological effect. The effect is probably a 15-20% reduction in the loss of C-peptide at approximately 1 year after treatment. This translates to an annual expected loss of between -0.250 and -0.235 pmol/ml in treated patients compared with an expected 2 h AUC loss of -0.294 pmol/ml at 1 year for untreated newly diagnosed patients. The biological effect of this vaccination should be developed further in order to reach clinically desirable reductions in insulin loss in patients recently diagnosed with type 1 diabetes.
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| 4. |
- Besser, Rachel E. J., et al.
(författare)
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Exploring C-peptide loss in type 1 diabetes using growth curve analysis
- 2018
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Ingår i: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 13:7
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Tidskriftsartikel (refereegranskat)abstract
- Objectives C-peptide (CP) loss in type 1 diabetes (T1D) is highly variable, and factors influencing it are poorly understood. We modelled CP values in T1D patients from diagnosis for up to 6 years, treating the serial data as growth curves plotted against time since diagnosis. The aims were to summarise the pattern of CP loss (i.e. growth curve shape) in individual patients in simple terms, and to identify baseline characteristics that predict this pattern in individuals. Materials and methods Between 1976 and 2011, 442 T1D patients initially aged amp;lt; 18y underwent 120-minute mixed meal tolerance tests (MMTT) to calculate area under the curve (AUC) CP, at 3, 9,18, 30, 48 and 72 months after diagnosis (n = 1537). The data were analysed using the novel SITAR mixed effects growth curve model (Superlmposition by Translation And Rotation). It fits a mean AUC growth curve, but also allows the curves mean level and rate of fall to vary between individuals so as to best fit the individual patient curves. These curve adjustments define individual curve shape. Results The square root (root) AUC scale provided the best fit. The mean levels and rates of fall for individuals were normally distributed and uncorrelated with each other. Age at diagnosis and root AUC at 3 months strongly predicted the patient-specific mean levels, while younger age at diagnosis (p amp;lt; 0.0001) and the 120-minute CP value of the 3-month MMTT (p = 0.002) predicted the patient-specific rates of fall. Conclusions SITAR growth curve analysis is a useful tool to assess CP loss in type 1 diabetes, explaining patient differences in terms of their mean level and rate of fall. A definition of rapid CP loss could be based on a quantile of the rate of fall distribution, allowing better understanding of factors determining CP loss and stratification of patients into targeted therapies.
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| 5. |
- Bird, Philippa K, et al.
(författare)
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Income inequality and social gradients in children's height : a comparison of cohort studies from five high-income countries.
- 2019
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Ingår i: BMJ Paediatrics Open. - : BMJ. - 2399-9772. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Health and well-being are better, on average, in countries that are more equal, but less is known about how this benefit is distributed across society. Height is a widely used, objective indicator of child health and predictor of lifelong well-being. We compared the level and slope of social gradients in children's height in high-income countries with different levels of income inequality, in order to investigate whether children growing up in all socioeconomic circumstances are healthier in more equal countries.Methods: We conducted a coordinated analysis of data from five cohort studies from countries selected to represent different levels of income inequality (the USA, UK, Australia, the Netherlands and Sweden). We used standardised methods to compare social gradients in children's height at age 4-6 years, by parent education status and household income. We used linear regression models and predicted height for children with the same age, sex and socioeconomic circumstances in each cohort.Results: The total analytic sample was 37 063 children aged 4-6 years. Gradients by parent education and household income varied between cohorts and outcomes. After adjusting for differences in age and sex, children in more equal countries (Sweden, the Netherlands) were taller at all levels of parent education and household income than children in less equal countries (USA, UK and Australia), with the greatest between-country differences among children with less educated parents and lowest household incomes.Conclusions: The study provides preliminary evidence that children across society do better in more equal countries, with greatest benefit among children from the most disadvantaged socioeconomic groups.
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| 6. |
- Bybrant, M. C., et al.
(författare)
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Tissue transglutaminase autoantibodies in children with newly diagnosed type 1 diabetes are related to human leukocyte antigen but not to islet autoantibodies: A Swedish nationwide prospective population-based cohort study
- 2018
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Ingår i: Autoimmunity. - : Informa UK Limited. - 0891-6934 .- 1607-842X. ; 51:5, s. 221-227
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: This study explored the association between tissue transglutaminase autoantibody (tTGA), high-risk human leucocyte antigen (HLA) genotypes and islet autoantibodies in children with newly diagnosed type 1 diabetes (T1D).Patients and methods: Dried blood spots and serum samples were taken at diagnosis from children <18years of age participating in Better Diabetes Diagnosis (BDD), a Swedish nationwide prospective cohort study of children newly diagnosed with T1D. We analyzed tTGA, high-risk HLA DQ2 and DQ8 (DQX is neither DQ2 nor DQ8) and islet auto-antibodies (GADA, IA-2A, IAA, and three variants of Zinc transporter; ZnT8W, ZnT8R, and ZnT8QA).Results: Out of 2705 children diagnosed with T1D, 85 (3.1%) had positive tTGA and 63 (2.3%) had borderline values. The prevalence of tTGA was higher in children with the HLA genotypes DQ2/2, DQ2/X or DQ2/8 compared to those with DQ8/8 or DQ8/X (p=.00001) and those with DQX/X (p.00001). No significant differences were found in relation to islet autoantibodies or age at diagnosis, but the presence of tTGA was more common in girls than in boys (p=.018).Conclusion: tTGA at T1D diagnosis (both positive and borderline values 5.4%) was higher in girls and in children homozygous for DQ2/2, followed by children heterozygous for DQ2. Only children with DQ2 and/or DQ8 had tTGA. HLA typing at the diagnosis of T1D can help to identify those without risk for CD.
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| 7. |
- Carlsson, Annelie, et al.
(författare)
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10 år med BDD-studien har gett bättre diabetesdiagnos hos barn : Studiens analysbatteri är nu klinisk rutin och kunskapen om olika diabetessjukdomar har ökat
- 2018
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Ingår i: Läkartidningen. - 0023-7205. ; 115:11, s. 484-484
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Tidskriftsartikel (refereegranskat)abstract
- The Swedish study Better Diabetes Diagnosis (BDD) has now been ongoing for ten years and detailed information and blood samples have been collected from more than 8000 children and adolescents with newly diagnosed diabetes. We have been able to demonstrate that by means of HLA diabetes antibodies and C-peptide the discrimination between type one and type 2 diabetes is improved. These analyses are therefore included in the clinical check-up for all children and adolescents in Sweden who are diagnosed with diabetes. Type 1 diabetes is by far the most prevalent type of diabetes among Swedish children and adolescents. Type 2 diabetes is still relatively rare in Sweden but it is urgent to obtain a correct diagnosis as the long-term prognosis depends on a prompt pharmacological treatment. Monogenic diabetes (MODY) is also important to identify early. We therefore recommend that sequencing of MODY genes should be performed if an individual with newly-diagnosed diabetes is auto-antibody negative and has an HLA pattern associated with low risk for type 1 diabetes. However, despite these analytical tools it can be difficult to make the correct diabetes diagnosis initially. It is therefore prudent to re-evaluate the diabetes diagnosis after one year.
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| 8. |
- Carlsson, Emma, et al.
(författare)
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High physical activity in young children suggests positive effects by altering autoantigen-induced immune activity
- 2016
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Ingår i: Scandinavian Journal of Medicine and Science in Sports. - : Wiley-Blackwell. - 0905-7188 .- 1600-0838. ; 26:4, s. 441-450
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Tidskriftsartikel (refereegranskat)abstract
- Physical activity in children is associated with several positive health outcomes such as decreased cardiovascular risk factors, improved lung function, enhanced motor skill development, healthier body composition, and also improved defense against inflammatory diseases. We examined how high physical activity vs a sedentary lifestyle in young children influences the immune response with focus on autoimmunity. Peripheral blood mononuclear cells, collected from 55 5-year-old children with either high physical activity (n = 14), average physical activity (n = 27), or low physical activity (n = 14), from the All Babies In Southeast Sweden (ABIS) cohort, were stimulated with antigens (tetanus toxoid and beta-lactoglobulin) and autoantigens (GAD65 , insulin, HSP60, and IA-2). Immune markers (cytokines and chemokines), C-peptide and proinsulin were analyzed. Children with high physical activity showed decreased immune activity toward the autoantigens GAD65 (IL-5, P < 0.05), HSP60 and IA-2 (IL-10, P < 0.05) and also low spontaneous pro-inflammatory immune activity (IL-6, IL-13, IFN-γ, TNF-α, and CCL2 (P < 0.05)) compared with children with an average or low physical activity. High physical activity in young children seems to have positive effects on the immune system by altering autoantigen-induced immune activity.
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| 9. |
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| 10. |
- Enander, Rebecka, et al.
(författare)
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Beta cell function after intensive subcutaneous insulin therapy or intravenous insulin infusion at onset of type 1 diabetes in children without ketoacidosis.
- 2018
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Ingår i: Pediatric diabetes. - : Hindawi Limited. - 1399-5448 .- 1399-543X. ; 19:6, s. 1079-1085
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Tidskriftsartikel (refereegranskat)abstract
- Our aim was to see if IV insulin therapy at diagnosis preserves beta-cell function better than multiple subcutaneous (SC) injections.Fifty-four children 9.9 ± 3.5 years (range 2.8-14.9) without ketoacidosis were included in a 2 years, randomized multicenter study with insulin SC or 48 to 72 hours IV initially. Thirty-three (61%) were boys, 22 (41%) were pubertal. Forty-eight subjects completed 12 months follow-up and 43 completed 24 months. At 1, 6, 12, and 24 months, hemoglobin A1c (HbA1c), C-peptide and insulin/kg/24 h were measured. At 24 months, a mixed-meal tolerance test (MMTT) was performed.HbA1c at diagnosis was 10.7%, (93 mmol/mol) for IV, 10.7%, (94 mmol/mol) for SC. During the first 2 full days of insulin therapy, mean plasma glucose was 8.2 mmol/L for IV, 9.5 for SC (P = .025). Mean insulin dose was 1.5 U/kg/d for IV vs 1.0 for SC (P = .001). Sixteen (7 in IV, 9 in SC group) started with insulin pumps during the follow-up. At 24 months, we saw no significant differences: HbA1c (7.5%, 58 mmol/mol, for IV, 7.2%, 55 mmol/mol, for SC; ns), insulin doses (0.79 vs 0.88 U/kg/d; ns), fasting C-peptide (0.08 vs 0.12 nmol/L; ns), maximal MMTT response (0.19 vs 0.25 nmol/L; ns) and AUC (18.26 vs 23.9 nmol/L*min; ns). Peak C-peptide >0.2 nmol/L in the combined IV and SC groups correlated significantly with HbA1c and C-peptide at onset in a multiple regression.Residual beta cell function at 2 years seems to be independent from initial insulin regimens but related to HbA1c and C-peptide at onset.
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