| 1. |
- 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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| 2. |
- Lindgren, Marie, et al.
(författare)
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Prevalence and Predictive Factors for Celiac Disease in Children With Type 1 Diabetes : Whom and When to Screen? A Nationwide Longitudinal Cohort Study of Swedish Children
- 2024
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Ingår i: Diabetes Care. - : American Diabetes Association. - 1935-5548 .- 0149-5992. ; 47:4, s. 756-760
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To examine the prevalence and predictive factors for celiac disease (CD) after a diagnosis of type 1 diabetes (T1D) in children and adolescents, to improve the current screening guidelines.RESEARCH DESIGN AND METHODS: The association between sex, age at T1D diagnosis, HLA, and diabetes autoantibodies, and a diagnosis of CD was examined in 5,295 children with T1D from the Better Diabetes Diagnosis study in Sweden.RESULTS: The prevalence of biopsy-proven CD was 9.8%, of which 58.2% already had a CD diagnosis before or at T1D onset. Almost all, 95.9%, were diagnosed with CD within 5 years after the T1D diagnosis. Younger age at the T1D diagnosis and being homozygote for DQ2 increased the risk of CD after T1D, but neither sex nor diabetes-related autoantibodies were associated with the risk.CONCLUSIONS: Age at and time after diabetes diagnosis should be considered in screening guidelines for CD in children with T1D.
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| 3. |
- Ping Zhao, Lue, et al.
(författare)
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Building and validating a prediction model for paediatric type 1 diabetes risk using next generation targeted sequencing of class II HLA genes
- 2017
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Ingår i: Diabetes/Metabolism Research Reviews. - : WILEY. - 1520-7552 .- 1520-7560. ; 33:8
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Tidskriftsartikel (refereegranskat)abstract
- AimIt is of interest to predict possible lifetime risk of type 1 diabetes (T1D) in young children for recruiting high-risk subjects into longitudinal studies of effective prevention strategies. MethodsUtilizing a case-control study in Sweden, we applied a recently developed next generation targeted sequencing technology to genotype class II genes and applied an object-oriented regression to build and validate a prediction model for T1D. ResultsIn the training set, estimated risk scores were significantly different between patients and controls (P=8.12x10(-92)), and the area under the curve (AUC) from the receiver operating characteristic (ROC) analysis was 0.917. Using the validation data set, we validated the result with AUC of 0.886. Combining both training and validation data resulted in a predictive model with AUC of 0.903. Further, we performed a biological validation by correlating risk scores with 6 islet autoantibodies, and found that the risk score was significantly correlated with IA-2A (Z-score=3.628, Pamp;lt;0.001). When applying this prediction model to the Swedish population, where the lifetime T1D risk ranges from 0.5% to 2%, we anticipate identifying approximately 20 000 high-risk subjects after testing all newborns, and this calculation would identify approximately 80% of all patients expected to develop T1D in their lifetime. ConclusionThrough both empirical and biological validation, we have established a prediction model for estimating lifetime T1D risk, using class II HLA. This prediction model should prove useful for future investigations to identify high-risk subjects for prevention research in high-risk populations.
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| 4. |
- Ping Zhao, Lue, et al.
(författare)
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Next-Generation Sequencing Reveals That HLA-DRB3, -DRB4, and -DRB5 May Be Associated With Islet Autoantibodies and Risk for Childhood Type 1 Diabetes
- 2016
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Ingår i: Diabetes. - : AMER DIABETES ASSOC. - 0012-1797 .- 1939-327X. ; 65:3, s. 710-718
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Tidskriftsartikel (refereegranskat)abstract
- The possible contribution of HLA-DRB3, -DRB4, and -DRB5 alleles to type 1 diabetes risk and to insulin autoantibody (IAA), GAD65 (GAD autoantibody [GADA]), IA-2 antigen (IA-2A), or ZnT8 against either of the three amino acid variants R, W, or Q at position 325 (ZnT8RA, ZnT8WA, and ZnT8QA, respectively) at clinical diagnosis is unclear. Next-generation sequencing (NGS) was used to determine all DRB alleles in consecutively diagnosed patients ages 1-18 years with islet autoantibody-positive type 1 diabetes (n = 970) and control subjects (n = 448). DRB3, DRB4, or DRB5 alleles were tested for an association with the risk of DRB1 for autoantibodies, type 1 diabetes, or both. The association between type 1 diabetes and DRB1*03:01:01 was affected by DRB3*01:01:02 and DRB3*02:02:01. These DRB3 alleles were associated positively with GADA but negatively with ZnT8WA, IA-2A, and IAA. The negative association between type 1 diabetes and DRB1*13:01:01 was affected by DRB3*01:01:02 to increase the risk and by DRB3*02:02:01 to maintain a negative association. DRB4*01:03:01 was strongly associated with type 1 diabetes (P = 10(-36)), yet its association was extensively affected by DRB1 alleles from protective (DRB1*04:03:01) to high (DRB1*04:01:01) risk, but its association with DRB1*04:05:01 decreased the risk. HLA-DRB3, -DRB4, and -DRB5 affect type 1 diabetes risk and islet autoantibodies. HLA typing with NGS should prove useful to select participants for prevention or intervention trials.
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| 5. |
- Tojjar, Jasaman, et al.
(författare)
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Sex Differences in Age of Diagnosis, HLA Genotype, and Autoantibody Profile in Children With Type 1 Diabetes
- 2023
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Ingår i: Diabetes care. - : American Diabetes Association. - 1935-5548 .- 0149-5992. ; 46:11, s. 1993-1996
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To examine sex differences in children with newly diagnosed type 1 diabetes (T1D) with respect to age at diagnosis, presence of autoantibodies (GAD antibody [GADA], insulinoma-associated protein 2 [IA-2A], insulin autoantibody [IAA], and zinc transporter 8 autoantibody), and HLA risk. RESEARCH DESIGN AND METHODS: A population-based nationwide sample of 3,645 Swedish children at T1D diagnosis was used. RESULTS: Girls were younger at T1D diagnosis (9.53 vs. 10.23 years; P < 0.001), more likely to be autoantibody-positive (94.7% vs. 92.0%; P = 0.002), more often positive for multiple autoantibodies (P < 0.001), more likely to be positive for GADA (64.9% vs. 49.0%; P < 0.001), and less likely to be positive for IAA (32.3% vs. 33.8%; P = 0.016). Small sex differences in HLA risk were found in children <9 years of age. CONCLUSIONS: The disease mechanisms leading to T1D may influence the immune system differently in girls and boys.
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| 6. |
- Zhao, Lue Ping, et al.
(författare)
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Eleven Amino Acids of HLA-DRB1 and Fifteen Amino Acids of HLA-DRB3, 4, and 5 Include Potentially Causal Residues Responsible for the Risk of Childhood Type 1 Diabetes
- 2019
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Ingår i: Diabetes. - Arlington, VA, United States : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 68:8, s. 1692-1704
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Tidskriftsartikel (refereegranskat)abstract
- Next-generation targeted sequencing of HLA-DRB1 and HLA-DRB3, -DRB4, and -DRB5 (abbreviated as DRB345) provides high resolution of functional variant positions to investigate their associations with type 1 diabetes risk and with autoantibodies against insulin (IAA), GAD65 (GADA), IA-2 (IA-2A), and ZnT8 (ZnT8A). To overcome exceptional DR sequence complexity as a result of high polymorphisms and extended linkage disequilibrium among the DR loci, we applied a novel recursive organizer (ROR) to discover disease-associated amino acid residues. ROR distills disease-associated DR sequences and identifies 11 residues of DRB1, sequences of which retain all significant associations observed by DR genes. Furthermore, all 11 residues locate under/adjoining the peptide-binding groove of DRB1, suggesting a plausible functional mechanism through peptide binding. The 15 residues of DRB345, located respectively in the beta 49-55 homodimerization patch and on the face of the molecule shown to interact with and bind to the accessory molecule CD4, retain their significant disease associations. Further ROR analysis of DR associations with autoantibodies finds that DRB1 residues significantly associated with ZnT8A and DRB345 residues with GADA. The strongest association is between four residues (beta 14, beta 25, beta 71, and beta 73) and IA-2A, in which the sequence ERKA confers a risk association (odds ratio 2.15, P = 10(-18)), and another sequence, ERKG, confers a protective association (odds ratio 0.59, P = 10(-11)), despite a difference of only one amino acid. Because motifs of identified residues capture potentially causal DR associations with type 1 diabetes, this list of residuals is expected to include corresponding causal residues in this study population.
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| 7. |
- Zhao, Lue Ping, et al.
(författare)
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Nine residues in HLA-DQ molecules determine with susceptibility and resistance to type 1 diabetes among young children in Sweden
- 2021
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- HLA-DQ molecules account over 50% genetic risk of type 1 diabetes (T1D), but little is known about associated residues. Through next generation targeted sequencing technology and deep learning of DQ residue sequences, the aim was to uncover critical residues and their motifs associated with T1D. Our analysis uncovered (αa1, α44, α157, α196) and (β9, β30, β57, β70, β135) on the HLA-DQ molecule. Their motifs captured all known susceptibility and resistant T1D associations. Three motifs, "DCAA-YSARD" (OR = 2.10, p = 1.96*10-20), "DQAA-YYARD" (OR = 3.34, 2.69*10-72) and "DQDA-YYARD" (OR = 3.71, 1.53*10-6) corresponding to DQ2.5 and DQ8.1 (the latter two motifs) associated with susceptibility. Ten motifs were significantly associated with resistance to T1D. Collectively, homozygous DQ risk motifs accounted for 43% of DQ-T1D risk, while homozygous DQ resistant motifs accounted for 25% protection to DQ-T1D risk. Of the identified nine residues five were within or near anchoring pockets of the antigenic peptide (α44, β9, β30, β57 and β70), one was the N-terminal of the alpha chain (αa1), one in the CD4-binding region (β135), one in the putative cognate TCR-induced αβ homodimerization process (α157), and one in the intra-membrane domain of the alpha chain (α196). Finding these critical residues should allow investigations of fundamental properties of host immunity that underlie tolerance to self and organ-specific autoimmunity.
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| 8. |
- Zhao, Lue Ping, et al.
(författare)
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The KAG motif of HLA-DRB1 (beta 71, beta 74, beta 86) predicts seroconversion and development of type 1 diabetes
- 2021
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Ingår i: EBioMedicine. - : Elsevier. - 2352-3964. ; 69
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Tidskriftsartikel (refereegranskat)abstract
- Background: HLA-DR4, a common antigen of HLA-DRB1, has multiple subtypes that are strongly associated with risk of type 1 diabetes (T1D); however, some are risk neutral or resistant. The pathobiological mechanism of HLA-DR4 subtypes remains to be elucidated. Methods: We used a population-based case-control study of T1D (962 patients and 636 controls) to decipher genetic associations of HLA-DR4 subtypes and specific residues with susceptibility to T1D. Using a birth cohort of 7865 children with periodically measured islet autoantibodies (GADA, IAA or IA-2A), we proposed to validate discovered genetic associations with a totally different study design and time-to-seroconversions prior to clinical onset of T1D. A novel analytic strategy hierarchically organized the HLA-DRB1 alleles by sequence similarity and identified critical amino acid residues by minimizing local genomic architecture and higher-order interactions. Findings: Three amino acid residues of HLA-DRB1 (beta 71, beta 74, beta 86) were found to be predictive of T1D risk in the population-based study. The " KAG" motif, corresponding to HLA-DRB1x04:01, was most strongly associated with T1D risk ([O]dds [R]atio=3.64, p = 3.19 x 10(-64)). Three less frequent motifs ("EAV", OR = 2.55, p = 0.025; "RAG", OR = 1.93, p = 0.043; and "RAV", OR = 1.56, p = 0.003) were associated with T1D risk, while two motifs ("REG" and "REV") were equally protective (OR = 0.11, p = 4.23 x 10(-4)). In an independent birth cohort of HLA-DR3 and HLA-DR4 subjects, those having the "KAG" motif had increased risk for time-to-seroconversion (Hazard Ratio = 1.74, p = 6.51 x 10(-14)) after adjusting potential confounders. Interpretations: DNA sequence variation in HLA-DRB1 at positions beta 71, beta 74, and beta 86 are non-conservative (beta 74 A -> E, beta 71 E vs K vs R and beta 86 G vs V). They result in substantial differences in peptide antigen anchor pocket preferences at p1, p4 and potentially neighboring regions such as pocket p7. Differential peptide antigen binding is likely to be affected. These sequence substitutions may account for most of the HLA-DR4 contribution to T1D risk as illustrated in two HLA-peptide model complexes of the T1D autoantigens preproinsulin and GAD65. (C) 2021 The Author(s). Published by Elsevier B.V.
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| 9. |
- Zhao, Lue Ping, et al.
(författare)
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The KAG motif of HLA-DRB1 (β71, β74, β86) predicts seroconversion and development of type 1 diabetes
- 2021
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Ingår i: EBioMedicine. - : Elsevier BV. - 2352-3964. ; 69
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: HLA-DR4, a common antigen of HLA-DRB1, has multiple subtypes that are strongly associated with risk of type 1 diabetes (T1D); however, some are risk neutral or resistant. The pathobiological mechanism of HLA-DR4 subtypes remains to be elucidated.METHODS: We used a population-based case-control study of T1D (962 patients and 636 controls) to decipher genetic associations of HLA-DR4 subtypes and specific residues with susceptibility to T1D. Using a birth cohort of 7865 children with periodically measured islet autoantibodies (GADA, IAA or IA-2A), we proposed to validate discovered genetic associations with a totally different study design and time-to-seroconversions prior to clinical onset of T1D. A novel analytic strategy hierarchically organized the HLA-DRB1 alleles by sequence similarity and identified critical amino acid residues by minimizing local genomic architecture and higher-order interactions.FINDINGS: Three amino acid residues of HLA-DRB1 (β71, β74, β86) were found to be predictive of T1D risk in the population-based study. The "KAG" motif, corresponding to HLA-DRB1×04:01, was most strongly associated with T1D risk ([O]dds [R]atio=3.64, p = 3.19 × 10-64). Three less frequent motifs ("EAV", OR = 2.55, p = 0.025; "RAG", OR = 1.93, p = 0.043; and "RAV", OR = 1.56, p = 0.003) were associated with T1D risk, while two motifs ("REG" and "REV") were equally protective (OR = 0.11, p = 4.23 × 10-4). In an independent birth cohort of HLA-DR3 and HLA-DR4 subjects, those having the "KAG" motif had increased risk for time-to-seroconversion (Hazard Ratio = 1.74, p = 6.51 × 10-14) after adjusting potential confounders.INTERPRETATIONS: DNA sequence variation in HLA-DRB1 at positions β71, β74, and β86 are non-conservative (β74 A→E, β71 E vs K vs R and β86 G vs V). They result in substantial differences in peptide antigen anchor pocket preferences at p1, p4 and potentially neighboring regions such as pocket p7. Differential peptide antigen binding is likely to be affected. These sequence substitutions may account for most of the HLA-DR4 contribution to T1D risk as illustrated in two HLA-peptide model complexes of the T1D autoantigens preproinsulin and GAD65.FUNDING: National Institute of Diabetes and Digestive and Kidney Diseases and the Swedish Child Diabetes Foundation and the Swedish Research Council.
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