| 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. |
- Delli, Ahmed, et al.
(författare)
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Zinc Transporter 8 Autoantibodies and Their Association With SLC30A8 and HLA-DQ Genes Differ Between Immigrant and Swedish Patients With Newly Diagnosed Type 1 Diabetes in the Better Diabetes Diagnosis Study
- 2012
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 61:10, s. 2556-2564
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Tidskriftsartikel (refereegranskat)abstract
- We examined whether zinc transporter 8 autoantibodies (ZnT8A; arginine ZnT8-RA, tryptophan ZnT8-WA, and glutamine ZnT8-QA variants) differed between immigrant and Swedish patients due to different polymorphisms of SLC30A8, HLA-DQ, or both. Newly diagnosed autoimmune (andgt;= 1 islet autoantibody) type 1 diabetic patients (n = 2,964, andlt;18 years, 55% male) were ascertained in the Better Diabetes Diagnosis study. Two subgroups were identified: Swedes (n = 2,160, 73%) and immigrants (non-Swedes; n = 212, 7%). Non-Swedes had less frequent ZnT8-WA (38%) than Swedes (50%), consistent with a lower frequency in the non-Swedes (37%) of SLC30A8 CT+TT (RW+WW) genotypes than in the Swedes (54%). ZnT8-RA (57 and 58%, respectively) did not differ despite a higher frequency of CC (RR) genotypes in non-Swedes (63%) than Swedes (46%). We tested whether this inconsistency was due to HLA-DQ as 2/X (2/2; 2/y; y is anything but 2 or 8), which was a major genotype in non-Swedes (40%) compared with Swedes (14%). In the non-Swedes only, 2/X (2/2; 2/y) was negatively associated with ZnT8-WA and ZnT8-QA but not ZnT8-RA. Molecular simulation showed nonbinding of the relevant ZnT8-R peptide to DQ2, explaining in part a possible lack of tolerance to ZnT8-R. At diagnosis in non-Swedes, the presence of ZnT8-RA rather than ZnT8-WA was likely due to effects of HLA-DQ2 and the SLC30A8 CC (RR) genotypes.
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| 3. |
- Galgani, Mario, et al.
(författare)
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Meta-Immunological Profiling of Children With Type 1 Diabetes Identifies New Biomarkers to Monitor Disease Progression
- 2013
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Ingår i: Diabetes. - : American Diabetes Association. - 1939-327X .- 0012-1797. ; 62:7, s. 2481-2491
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Tidskriftsartikel (refereegranskat)abstract
- Type 1 diabetes is characterized by autoimmurte destruction of pancreatic beta-cells in genetically susceptible individuals. Triggers of islet autoimmunity, time course, and the precise mechanisms responsible for the progressive beta-cell failure are not completely understood. The recent escalation of obesity in affluent countries has been suggested to contribute to the increased incidence of type 1 diabetes. Understanding the link between metabolism and immune tolerance could lead to the identification of new markers for the monitoring of disease onset and progression. We studied several immune cell subsets and factors with high metabolic impact as markers associated with disease progression in high-risk subjects and type 1 diabetic patients at onset and at 12 and 24 months after diagnosis. A multiple correlation matrix among different parameters was evaluated statistically and assessed visually on two-dimensional graphs. Markers to predict residual beta-cell function up to 1 year after diagnosis were identified in multivariate logistic regression models. The meta-immunological profile changed significantly over time in patients, and a specific signature that was associated with worsening disease was identified. A multivariate logistic regression model measuring age, BMI, fasting C-peptide, number of circulating CD3(+)CD16(+)CD56(+) cells, and the percentage of CD1c(+)CD19(-)CD14(-)CD303(-) type 1 myeloid dendritic cells at disease onset had a significant predictive value. The identification of a specific meta-immunological profile associated with disease status may contribute to our understanding of the basis of diabetes progression.
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| 4. |
- Graham, J, et al.
(författare)
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Genetic effects on age-dependent onset and islet cell autoantibody markers in type 1 diabetes
- 2002
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 51:5, s. 1346-1355
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Tidskriftsartikel (refereegranskat)abstract
- Age-dependent associations between type 1 diabetes risk genes HLA, INS VNTR, and CTLA-4 and autoantibodies to GAD65 (GADAs), ICA512/IA-2, insulin, and islet cells were determined by logistic regression analysis in 971 incident patients with type 1 diabetes and 702 control subjects aged 0–34 years. GADAs were associated with HLA-DQ2 in young but not in older patients (P = 0.009). Autoantibodies to insulin were negatively associated with age (P < 0.0001) but positively associated with DQ8 (P = 0.03) and with INS VNTR (P = 0.04), supporting possible immune tolerance induction. ICA512/IA-2 were negatively associated with age (P < 0.0001) and with DQ2 (P < 0.0001) but positively associated with DQ8 (P = 0.04). Males were more likely than females to be negative for GADA (P < 0.0001), autoantibodies to islet cells (P = 0.04), and all four autoantibody markers (P = 0.004). The CTLA-4 3′ end microsatellite marker was not associated with any of the autoantibodies. We conclude that age and genetic factors such as HLA-DQ and INS VNTR need to be combined with islet autoantibody markers when evaluating the risk for type 1 diabetes development.
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| 5. |
- Hippich, Markus, et al.
(författare)
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Genetic contribution to the divergence in type 1 diabetes risk between children from the general population and children from affected families
- 2019
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 68:4, s. 847-857
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Tidskriftsartikel (refereegranskat)abstract
- The risk for autoimmunity and subsequently type 1 diabetes is 10-fold higher in children with a first-degree family history of type 1 diabetes (FDR children) than in children in the general population (GP children). We analyzed children with high-risk HLA genotypes (n = 4,573) in the longitudinal TEDDY birth cohort to determine how much of the divergent risk is attributable to genetic enrichment in affected families. Enrichment for susceptible genotypes of multiple type 1 diabetes–associated genes and a novel risk gene, BTNL2, was identified in FDR children compared with GP children. After correction for genetic enrichment, the risks in the FDR and GP children converged but were not identical for multiple islet autoantibodies (hazard ratio [HR] 2.26 [95% CI 1.6–3.02]) and for diabetes (HR 2.92 [95% CI 2.05–4.16]). Convergence varied depending upon the degree of genetic susceptibility. Risks were similar in the highest genetic susceptibility group for multiple islet autoantibodies (14.3% vs .12.7%) and diabetes (4.8% vs. 4.1%) and were up to 5.8-fold divergent for children in the lowest genetic susceptibility group, decreasing incrementally in GP children but not in FDR children. These findings suggest that additional factors enriched within affected families preferentially increase the risk of autoimmunity and type 1 diabetes in lower genetic susceptibility strata.
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| 6. |
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| 7. |
- Krischer, Jeffrey P., et al.
(författare)
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The Influence of Type 1 Diabetes Genetic Susceptibility Regions, Age, Sex, and Family History to the Progression from Multiple Autoantibodies to Type 1 Diabetes:A TEDDY Study Report : A TEDDY Study Report
- 2017
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Ingår i: Diabetes. - : American Diabetes Association. - 1939-327X .- 0012-1797. ; 66:12, s. 3122-3129
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Tidskriftsartikel (refereegranskat)abstract
- This paper seeks to determine whether factors related to autoimmunity risk remain significant after the initiation of two or more diabetes-related autoantibodies and continue to contribute to T1D risk among autoantibody positive children in The Environmental Determinants of Diabetes in the Young (TEDDY) study. Characteristics included are age at multiple autoantibody positivity, sex, selected high-risk HLA-DR-DQ genotypes, relationship to a family member with T1D, autoantibody at seroconversion, INS gene (rs1004446_A), and non-HLA gene polymorphisms identified by the Type 1 Diabetes Genetics Consortium. The risk of progression to T1D was not different among those with or without a family history of T1D (p=0.39) nor HLA-DR-DQ genotypes (p=0.74). Age at developing multiple autoantibodies (HR=0.96 per 1 month increase in age, 95% CI=0.95, 0.97, p<0.001) and the type of first autoantibody (when more than a single autoantibody was the first appearing indication of seroconversion [p=0.006]) were statistically significant. Female sex was also a significant risk factor (p=0.03). Three SNPs were associated with increased diabetes risk (rs10517086_A, [p=0.03], rs1534422_G, [p=0.006], and rs2327832_G in TNFAIP3 [p=0.03]), and one with decreased risk (rs1004446_A in INS, [p=0.006]). The TEDDY data suggest that non-HLA gene polymorphisms may play a different role in the initiation of autoimmunity than they do in progression to T1D once autoimmunity has appeared. The strength of these associations may be related to the age of the population and the high-risk HLA-DR-DQ subtypes studied.
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| 8. |
- Kwon, Bum Chul, et al.
(författare)
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Islet Autoantibody Levels Differentiate Progression Trajectories in Individuals with Presymptomatic Type 1 Diabetes
- 2022
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Ingår i: Diabetes. - : American Diabetes Association. - 1939-327X .- 0012-1797. ; 71:12, s. 2632-2641
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Tidskriftsartikel (refereegranskat)abstract
- Our previous data-driven analysis of evolving patterns of islet autoantibodies (IAbs) against insulin (IAA), glutamic acid decarboxylase (GADA) and islet antigen 2 (IA-2A) discovered three trajectories characterized by either multiple IAbs (TR1), IAA (TR2), or GADA (TR3) as the first appearing autoantibodies. Here we examined the evolution of IAb levels within these trajectories in 2,145 IAb-positive participants followed from early life and compared those who progressed to type 1 diabetes (n=643) to those remaining undiagnosed (n=1,502). Using thresholds determined by 5-year diabetes risk, four levels were defined for each IAb and overlayed onto each visit. In diagnosed participants, high IAA levels were seen in TR1 and TR2 at ages <3 years, whereas IAA remained at lower levels in the undiagnosed. Proportions of dwell times (total duration of follow-up at a given level) at the four IAb levels differed between the diagnosed and undiagnosed for GADA and IA-2A in all three trajectories (p<0.001), but for IAA dwell times differed only within TR2 (p<0.05). Overall, undiagnosed participants more frequently had low IAb levels and later appearance of IAb than diagnosed participants. In conclusion, while it has been long appreciated that the number of autoantibodies is an important predictor of type 1 diabetes, consideration of autoantibody levels within the three autoimmune trajectories improved differentiation of IAb positive children who progressed to type 1 diabetes from those who did not.
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| 9. |
- La Torre, Daria, et al.
(författare)
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Decreased cord-blood phospholipids in young age-at-onset type 1 diabetes
- 2013
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 62:11, s. 3951-3956
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Tidskriftsartikel (refereegranskat)abstract
- Children developing type 1 diabetes may have risk markers already in their umbilical cord blood. It is hypothesized that the risk for type 1 diabetes at an early age may be increased by a pathogenic pregnancy and be reflected in altered cord-blood composition. This study used metabolomics to test if the cord-blood lipidome was affected in children diagnosed with type 1 diabetes before 8 years of age. The present case-control study of 76 index children diagnosed with type 1 diabetes before 8 years of age and 76 healthy control subjects matched for HLA risk, sex, and date of birth, as well as the mother's age and gestational age, revealed that cord-blood phosphatidylcholines and phosphatidylethanolamines were significantly decreased in children diagnosed with type 1 diabetes before 4 years of age. Reduced levels of triglycerides correlated to gestational age in index and control children and to age at diagnosis only in the index children. Finally, gestational infection during the first trimester was associated with lower cord-blood total lysophosphatidylcholines in index and control children. In conclusion, metabolomics of umbilical cord blood may identify children at increased risk for type 1 diabetes. Low phospholipid levels at birth may represent key mediators of the immune system and contribute to early induction of islet autoimmunity.
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| 10. |
- Larsson, Helena Elding, et al.
(författare)
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Growth and risk for islet autoimmunity and progression to type 1 diabetes in early childhood : The environmental determinants of diabetes in the young study
- 2016
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 65:7, s. 1988-1995
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Tidskriftsartikel (refereegranskat)abstract
- Increased growth in early childhood has been suggested to increase the risk of type 1 diabetes. This study explored the relationship between weight or height and development of persistent islet autoimmunity and progression to type 1 diabetes during the first 4 years of life in 7,468 children at genetic risk for type 1 diabetes followed in Finland, Germany, Sweden, and the U.S. Growth data collected every third month were used to estimate individual growth curves by mixed models. Cox proportional hazards models were used to evaluate body size and risk of islet autoimmunity and type 1 diabetes. In the overall cohort, development of islet autoimmunity (n = 575) was related to weight z scores at 12 months (hazard ratio [HR] 1.16 per 1.14 kg in males or per 1.02 kg in females, 95% CI 1.06-1.27, P <0.001, false discovery rate [FDR] = 0.008) but not at 24 or 36 months. A similar relationship was seen between weight z scores and development of multiple islet autoantibodies (1 year: HR 1.21, 95% CI 1.08-1.35, P = 0.001, FDR = 0.008; 2 years: HR 1.18, 95% CI 1.06-1.32, P = 0.004, FDR = 0.02). No association was found between weight or height and type 1 diabetes (n = 169). In conclusion, greater weight in the first years of life was associated with an increased risk of islet autoimmunity.
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