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.

Aim Previous studies have reported an association between month of birth and incidence of type 1 diabetes. Using population-based data, including almost all newly diagnosed children with type 1 diabetes in Sweden, we tested whether month of birth influences the risk of type 1 diabetes. Methods For 8761 children diagnosed with type 1 diabetes between May 2005 and December 2016 in the Better Diabetes Diagnosis study, month of birth, sex and age were compared. Human leucocyte antigen (HLA) genotype and autoantibodies at diagnosis were analysed for a subset of the cohort (n = 3647). Comparisons with the general population used data from Statistics Sweden. Results We found no association between month of birth or season and the incidence of type 1 diabetes in the cohort as a whole. However, boys diagnosed before 5 years were more often born in May (p = 0.004). We found no correlation between month of birth and HLA or antibodies. Conclusion In this large nationwide study, the impact of month of birth on type 1 diabetes diagnosis was weak, except for boys diagnosed before 5 years of age, who were more likely born in May. This may suggest different triggers for different subgroups of patients with type 1 diabetes.

Objectives Children with type 1 diabetes (T1D) are not included in guidelines regarding diagnosis criteria for celiac disease (CD) without a diagnostic biopsy, due to lack of data. We explored whether tissue transglutaminase antibodies (anti-tTG) that were &gt;= 10 times the upper limit of normal (10x ULN) predicted CD in T1D. Methods Data from the Swedish prospective Better Diabetes Diagnosis study was used, and 2035 children and adolescents with T1D diagnosed between 2005-2010 were included. Of these, 32 had been diagnosed with CD before T1D. The children without CD were repeatedly screened for CD using anti-tTG antibodies of immunoglobulin type A. In addition, their human leukocyte antigen (HLA) were genotyped. All children with positive anti-tTG were advised to undergo biopsy. Biopsies were performed on 119 children and graded using the Marsh-Oberhuber classification. Results All of the 60 children with anti-tTG &gt;= 10x ULN had CD verified by biopsies. The degree of mucosal damage correlated with anti-tTG levels. Among 2003 screened children, 6.9% had positive anti-tTG and 5.6% were confirmed CD. The overall CD prevalence, when including the 32 children with CD before T1D, was 7.0% (145/2035). All but one of the children diagnosed with CD had HLA-DQ2 and/or DQ8. Conclusions As all screened children and adolescents with T1D with tissue transglutaminase antibodies above 10 times the positive value 10x ULN had CD, we propose that the guidelines for diagnosing CD in screened children, when biopsies can be omitted, should also apply to children and adolescents with T1D as a noninvasive method.

Objective This study aimed to compare metabolic control measured as hemoglobin A1c (HbA1c), the risk of severe hypoglycemia, and body composition measured as body mass index standard deviation scores (BMI-SDS) in a nationwide sample of children and adolescents with Type 1 diabetes with continuous subcutaneous insulin infusion (CSII) and multiple daily injections (MDI), respectively. Research Design and Methods Longitudinal data from 2011 to 2016 were extracted from the Swedish National Quality Register (SWEDIABKIDS) with both cross-sectional (6 years) and longitudinal (4 years) comparisons. Main end points were changes in HbA1c, BMI-SDS, and incidence of severe hypoglycemia. Results Data were available from 35,624 patient-years (54% boys). In general, HbA1c decreased approximately 0.5% (2-5 mmol/mol) from 2011 to 2016 (p(trend) &lt; 0.001) and the use of CSII increased in both sexes and all age groups. Mean HbA1c was 0.1% (0.7-1.5 mmol/mol) lower in the CSII treated group. Teenagers, especially girls, using CSII tended to have higher BMI-SDS. There was no difference in the number of hypoglycemias between CSII and MDI over the years 2011-2016. Conclusions There was a small decrease in HbA1c with CSII treatment but of little clinical relevance. Overall, mean HbA1c decreased in both sexes and all age groups without increasing the episodes of severe hypoglycemia, indicating that other factors than insulin method contributed to a better metabolic control.

OBJECTIVE To evaluate the efficacy of aluminum-formulated intralymphatic glutamic acid decarboxylase (GAD-alum) therapy combined with vitamin D supplementation in preserving endogenous insulin secretion in all patients with type 1 diabetes (T1D) or in a genetically prespecified subgroup. RESEARCH DESIGN AND METHODS In a multicenter, randomized, placebo-controlled, double-blind trial, 109 patients aged 12-24 years (mean +/- SD 16.4 +/- 4.1) with a diabetes duration of 7-193 days (88.8 +/- 51.4), elevated serum GAD65 autoantibodies, and a fasting serum C-peptide &gt;0.12 nmol/L were recruited. Participants were randomized to receive either three intralymphatic injections (1 month apart) with 4 mu g GAD-alum and oral vitamin D (2,000 IE daily for 120 days) or placebo. The primary outcome was the change in stimulated serum C-peptide (mean area under the curve [AUC] after a mixed-meal tolerance test) between baseline and 15 months. RESULTS Primary end point was not met in the full analysis set (treatment effect ratio 1.091 [CI 0.845-1.408]; P = 0.5009). However, GAD-alum-treated patients carrying HLA DR3-DQ2 (n = 29; defined as DRB1*03, DQB1*02:01) showed greater preservation of C-peptide AUC (treatment effect ratio 1.557 [CI 1.126-2.153]; P = 0.0078) after 15 months compared with individuals receiving placebo with the same genotype (n = 17). Several secondary end points showed supporting trends, and a positive effect was seen in partial remission (insulin dose-adjusted HbA(1c) &lt;= 9; P = 0.0310). Minor transient injection site reactions were reported. CONCLUSION Intralymphatic administration of GAD-alum is a simple, well-tolerated treatment that together with vitamin D supplementation seems to preserve C-peptide in patients with recent-onset T1D carrying HLA DR3-DQ2. This constitutes a disease-modifying treatment for T1D with a precision medicine approach.

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 (alpha a1, alpha 44, alpha 157, alpha 196) and (beta 9, beta 30, beta 57, beta 70, beta 135) 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 (alpha 44, beta 9, beta 30, beta 57 and beta 70), one was the N-terminal of the alpha chain (alpha a1), one in the CD4-binding region (beta 135), one in the putative cognate TCR-induced alpha beta homodimerization process (alpha 157), and one in the intra-membrane domain of the alpha chain (alpha 196). Finding these critical residues should allow investigations of fundamental properties of host immunity that underlie tolerance to self and organ-specific autoimmunity.

Aim/hypothesis Environmental factors are believed to contribute to the risk of developing type 1 diabetes. The aim of this study was to investigate how size for gestational age affects the risk of developing childhood type 1 diabetes.

Methods Using the Swedish paediatric diabetes quality register and the Swedish medical birth register, children with type 1 diabetes diagnosed between 2000 and 2012 (n = 9376) were matched with four control children (n = 37,504). Small for gestational age (SGA) and large for gestational age (LGA) were defined according to Swedish national standards. Data were initially analysed using Pearsons chi(2) and thereafter by single and multiple logistic regression models.

Results An equal proportion of children were born appropriate for gestational age, but children with type 1 diabetes were more often born LGA and less often born SGA than control children (4.7% vs 3.5% and 2.0% vs 2.6%, respectively, p &lt; 0.001). In the multiple logistic regression analysis, being born LGA increased (adjusted OR 1.16 [95% CI 1.02, 1.32]) and SGA decreased (adjusted OR 0.76 [95% CI 0.63, 0.92]) the risk for type 1 diabetes, regardless of maternal BMI and diabetes.

Conclusions/interpretation Size for gestational age of Swedish children affects the risk of type 1 diabetes, with increased risk if the child is born LGA and decreased risk if the child is born SGA. Being born LGA is an independent risk factor for type 1 diabetes irrespective of maternal BMI and diabetes. Thus, reducing the risk for a child being born LGA might to some extent reduce the risk for type 1 diabetes.

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 -&gt; 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.

OBJECTIVE Identifying maturity-onset diabetes of the young (MODY) in pediatric populations close to diabetes diagnosis is difficult. Misdiagnosis and unnecessary insulin treatment are common. We aimed to identify the discriminatory clinical features at diabetes diagnosis of patients with glucokinase (GCK), hepatocyte nuclear factor-1A (HNF1A), and HNF4A MODY in the pediatric population.

RESEARCH DESIGN AND METHODS Swedish patients (n = 3,933) aged 1–18 years, diagnosed with diabetes May 2005 to December 2010, were recruited from the national consecutive prospective cohort Better Diabetes Diagnosis. Clinical data, islet autoantibodies (GAD insulinoma antigen-2, zinc transporter 8, and insulin autoantibodies), HLA type, and C-peptide were collected at diagnosis. MODY was identified by sequencing GCK, HNF1A, and HNF4A, through either routine clinical or research testing.

RESULTS The minimal prevalence of MODY was 1.2%. Discriminatory factors for MODY at diagnosis included four islet autoantibody negativity (100% vs. 11% not-known MODY; P = 2 × 10−44), HbA1c (7.0% vs. 10.7% [53 vs. 93 mmol/mol]; P = 1 × 10−20), plasma glucose (11.7 vs. 26.7 mmol/L; P = 3 × 10−19), parental diabetes (63% vs. 12%; P = 1 × 10−15), and diabetic ketoacidosis (0% vs. 15%; P = 0.001). Testing 303 autoantibody-negative patients identified 46 patients with MODY (detection rate 15%). Limiting testing to the 73 islet autoantibody-negative patients with HbA1c <7.5% (58 mmol/mol) at diagnosis identified 36 out of 46 (78%) patients with MODY (detection rate 49%). On follow-up, the 46 patients with MODY had excellent glycemic control, with an HbA1c of 6.4% (47 mmol/mol), with 42 out of 46 (91%) patients not on insulin treatment.

CONCLUSIONS At diagnosis of pediatric diabetes, absence of all islet autoantibodies and modest hyperglycemia (HbA1c <7.5% [58 mmol/mol]) should result in testing for GCK, HNF1A, and HNF4A MODY. Testing all 12% patients negative for four islet autoantibodies is an effective strategy for not missing MODY but will result in a lower detection rate. Identifying MODY results in excellent long-term glycemic control without insulin.

HLA-DQA1 and -DQB1 are strongly associated with type 1 diabetes (T1D), and DQ8.1 and DQ2.5 are major risk haplotypes. Next-generation targeted sequencing of HLA-DQA1 and -DQB1 in Swedish newly diagnosed 1- to 18 year-old patients (n= 962) and control subjects (n= 636) was used to construct abbreviated DQ haplotypes, converted into amino acid (AA) residues, and assessed for their associations with T1D. A hierarchically organized haplotype (HOH) association analysis allowed 45 unique DQ haplotypes to be categorized into seven clusters. The DQ8/9 cluster included two DQ8.1 risk and the DQ9 resistant haplotypes, and the DQ2 cluster included the DQ2.5 risk and DQ2.2 resistant haplotypes. Within each cluster, HOH found residues alpha 44Q (odds ratio [OR] 3.29,P= 2.38 * 10(-85)) and beta 57A (OR 3.44,P= 3.80 * 10(-84)) to be associated with T1D in the DQ8/9 cluster representing all ten residues (alpha 22, alpha 23, alpha 44, alpha 49, alpha 51, alpha 53, alpha 54, alpha 73, alpha 184, beta 57) due to complete linkage disequilibrium (LD) of alpha 44 with eight such residues. Within the DQ2 cluster and due to LD, HOH analysis found alpha 44C and beta 135D to share the risk for T1D (OR 2.10,P= 1.96 * 10(-20)). The motif "QAD" of alpha 44, beta 57, and beta 135 captured the T1D risk association of DQ8.1 (OR 3.44,P= 3.80 * 10(-84)), and the corresponding motif "CAD" captured the risk association of DQ2.5 (OR 2.10,P= 1.96 * 10(-20)). Two risk associations were related to GAD65 autoantibody (GADA) and IA-2 autoantibody (IA-2A) but in opposite directions. CAD was positively associated with GADA (OR 1.56,P= 6.35 * 10(-8)) but negatively with IA-2A (OR 0.59,P= 6.55 * 10(-11)). QAD was negatively associated with GADA (OR 0.88;P= 3.70 * 10(-3)) but positively with IA-2A (OR 1.64;P= 2.40 * 10(-14)), despite a single difference at alpha 44. The residues are found in and around anchor pockets 1 and 9, as potential T-cell receptor contacts, in the areas for CD4 binding and putative homodimer formation. The identification of three HLA-DQ AAs (alpha 44, beta 57, beta 135) conferring T1D risk should sharpen functional and translational studies.