Diabetes Prediction In Skåne Research Articles

Decreased HLA-DQ expression on peripheral blood cells in children with varying number of beta cell autoantibodies

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.

Childhood thyroid autoimmunity and relation to islet autoantibodies in children at risk for type 1 diabetes in the diabetes prediction in skåne (DiPiS) study

Background: The aim was to determine prevalence and age at seroconversion of thyroid autoimmunity in relation to islet autoantibodies, gender and HLA-DQ genotypes in children with increased risk for type 1 diabetes followed from birth.Methods: In 10-year-old children (n = 1874), blood samples were analysed for autoantibodies against thyroid peroxidase (TPOAb), thyroglobulin (TGAb), glutamic acid decarboxylase 65 (GADA), Zink transporter 8 (ZnT8R/W/QA), insulinoma-associated protein-2 (IA-2A), insulin (IAA) and HLA-DQ genotypes. Prospectively collected samples from 2 years of age were next analysed for TPOAb, and TGAb and, finally, in confirming samples at 11–16 years of age along with TSH and FT4. Frequencies were tested with Chi-square or Fischer’s exact tests, autoantibody levels with Wilcoxon and correlations between autoantibody levels with Spearman’s rank correlation test.Results: The prevalence of thyroid autoimmunity was 6.9%, overrepresented in girls (p < .001) also having higher TPOAb levels at 10 years (p = .049). TPOAb was associated with GADA (p = .002), ZnT8R/W/QA (p = .001) and IA-2A (p = .001) while TGAb were associated with ZnT8R/W/QA (p = .021). In boys only, TPOAb were associated with GADA (p = .002), IA-2A (p = .001), ZnT8R/W/QA (p = .001) and IAA (p = .009), and TGAb with GADA (p = .013), IA-2A (p = .005) and ZnT8R/W/QA (p = .003). Levels of IA-2A correlated to both TPOAb (p = .021) and to TGAb (p = .011). In boys only, levels of GADA and TGAb correlated (p = .009 as did levels of IA-2A and TPOAb (p = .013). The frequency and levels of thyroid autoantibodies increased with age. At follow-up, 22.3% had abnormal thyroid function or were treated with thyroxine.Conclusions: Thyroid autoimmunity and high TPOAb levels were more common in girls. In contrast, in boys only, there was a strong association with as well as correlation between levels of thyroid and islet autoantibodies. It is concluded that while girls may develop autoimmune thyroid disease (AITD) independent of islet autoantibodies, the risk for thyroid disease in boys may be linked to concomitant islet autoimmunity.

Are Perinatal Events Risk Factors for Childhood Thyroid Autoimmunity

Background: Environmental and genetic factors possibly trigger thyroid autoimmunity. Studies on perinatal risk factors for childhood thyroid autoimmunity are sparse. Objectives: The aim was to investigate if perinatal factors, family history of autoimmune diseases, and HLA-DQ genotypes contribute to thyroid autoimmunity in the Diabetes Prediction in Skåne (DiPiS) study. Methods: Samples from 1,874 ten-year-old children were analyzed for autoantibodies to thyroid peroxidase (TPOAb), thyroglobulin (TGAb), and HLA-DQ genotypes. Information on perinatal events and family history of autoimmunity was gathered prospectively in questionnaires. Results: Thyroid autoimmunity was found in 6.9% of the children (TPOAb 4.4%, TGAb 5.8%, both autoantibodies 3.3%) and was overrepresented in girls. Prematurity was positively related to TGAb (OR: 2.4, p = 0.003, p_c = 0.021). Autoimmune diseases in the family increased the risk of thyroid autoimmunity: TPOAb (OR: 2.2, p = 0.012), any autoantibody (OR: 1.7, p = 0.04), and both autoantibodies (OR: 2.2, p = 0.024). A first-degree relative (FDR) with thyroid disease increased the risk for TPOAb (OR: 2.4, p = 0.03) and both autoantibodies (OR: 2.6, p = 0.03), a FDR or sibling with celiac disease increased the risk for both autoantibodies (OR: 3.7, p = 0.03, and OR: 4.8, p = 0.003), a FDR or sibling with diabetes increased the risk for thyroid autoantibody (OR: 3.0, p = 0.01, and OR: 5.4, p = 0.032), and a father with rheumatic disease increased the risk for TPOAb (OR: 15.2, p = 0.017), TGAb (OR: 11.3, p = 0.029), any autoantibody (OR: 9.6, p = 0.038), and both autoantibodies (OR: 20, p = 0.01). Conclusions: Thyroid autoimmunity was found in 6.9% of the 10-year-old children who were being followed for their risk of type 1 diabetes. No relation to perinatal factors was found, with the exception of a possible association between prematurity and TGAb. Family history of autoimmune diseases increased the risk of thyroid autoimmunity.

Cord blood insulinoma-associated protein 2 autoantibodies are associated with increased risk of type 1 diabetes in the population-based Diabetes Prediction in Skåne study.

The aim of this study was to examine the effect of cord blood autoantibodies on the risk for type 1 diabetes in children followed prospectively from birth. The Diabetes Prediction in Skåne (DiPiS) study consists of 35,853 children from the general population born during 2000-2004. Samples were collected at birth and analysed for HLA genotypes and autoantibodies to glutamate decarboxylase 65 (GAD65), insulin and insulinoma-associated protein 2 (IA-2). After adjusting for HLA, sex, maternal age and parental type 1 diabetes, independent associations with risk of diabetes were assessed using multivariate Cox proportional hazards models. In total, 151 children (0.4%) had developed type 1 diabetes by the end of 2013 at a median age of 5.8 years (0.8-12.2 years). In the multivariate analysis, the presence of IA-2 autoantibodies (IA-2A) in cord blood (HR 6.88, 95% CI 1.46,32.4; p = 0.003), but not maternal diabetes (HR 1.38, 95% CI 0.24,7.84; p = 0.71), was associated with risk of developing type 1 diabetes. No increased risk could be seen for the presence of autoantibodies to GAD65 or insulin. Our study indicates that the presence of cord blood IA-2A superimposes maternal diabetes and other cord blood islet autoantibodies as a predictor of type 1 diabetes development in the child. These findings may be of significance for future screening and study protocols on type 1 diabetes prediction.

Reduced morbidity at diagnosis and improved glycemic control in children previously enrolled in DiPiS follow-up.

Children participating in longitudinal type 1 diabetes prediction studies were reported to have less severe disease at diabetes diagnosis. Our aim was to investigate children who from birth participated in the Diabetes Prediction in Skåne (DiPiS) study for metabolic status at diagnosis and then continued to be followed for 2 yr of regular clinical care. Children, followed in DiPiS before diagnosis, were compared to children in the same birth cohort, who did not participate in follow-up. Metabolic status, symptoms at diagnosis as well as hemoglobin A1c (HbA1c) and doses of insulin at 3, 6, 12, and 24 months after diagnosis were compared. Children, followed in DiPiS and diagnosed at 2-12 yr of age, had 0.8% (9 mmol/mol) lower HbA1c at diagnosis than those who were not followed (p = 0.006). At diagnosis, fewer DiPiS children had symptoms (p = 0.014) and ketoacidosis at diagnosis were reduced (2% compared to 18%, p = 0.005). During regular clinical care, HbA1c levels for the DiPiS children remained lower both at 12 (0.4% (4 mmol/mol); p = 0.009) and 24 months (0.8% (9 mmol/mol) p < 0.001) after diagnosis, despite no difference in total daily insulin between the two groups. Participation in prospective follow-up before diagnosis of type 1 diabetes leads to earlier diagnosis with fewer symptoms, decreased incidence of ketoacidosis as well as better metabolic control up to 2 yr after diagnosis. Our data indicate that metabolic control at the time of diabetes diagnosis is important for early metabolic control possibly affecting the risk of long-term complications.

Early-Pregnancy Cytokines in Mothers to Children Developing Multiple, Persistent Islet Autoantibodies, Type 1 Diabetes, or Both Before 7 Years of Age

Increased levels of serum cytokines in early pregnancy may increase the risk of type 1 diabetes in the offspring. Early-pregnancy (between 10 and 16 gestational weeks) serum samples from non-diabetic index mothers (n = 48) of children who developed islet autoimmunity, type 1 diabetes, or both before 7 years of age were analyzed for IFN-γ, IL-10, IL-12, IL-13, IL-1β, IL-2, IL-4, IL-5, CXCL8, and TNF. Control mothers (n = 93) were matched for age, sampling date, and HLA-DQ genotypes. IFN-γ (P = 0.02) and IL-1β (P = 0.04) were elevated in the index mothers. All cytokines except IL-4 were highly correlated (P < 0.0001). IFN-γ [OR 1.39 (1.04, 1.85), P = 0.026] and possibly IL-2 [OR 1.21 (0.99, 1.48), P = 0.057] in early pregnancy were associated with an increased risk of multiple, persistent islet autoantibodies, type 1 diabetes, or both before 7 years of age in the offspring. However, the statistical significance for IL-2 was lost in the logistic regression when adjusted for gestational length at delivery and parity. Increased Th1 cytokine levels during early pregnancy might contribute to an increased risk of islet autoimmunity, type 1 diabetes, or both in the offspring.

Seroconversion to islet autoantibodies between early pregnancy and delivery in non-diabetic mothers

Islet autoantibodies are currently used to classify type 1 diabetes at diagnosis as they reflect the autoimmune pathogenesis of the disease. The presence of maternal autoantibodies reactive with pancreatic islet antigens is thought to increase the risk for type 1 diabetes in the offspring. The objective of this study was to determine seroconversion to islet autoantibodies in non-diabetic mothers during pregnancy. Screening of 33,682 mothers between September 2000 and August 2004 in the Diabetes Prediction in Skåne (DiPiS) study showed that at delivery, 242 non-diabetic mothers had increased titers of islet autoantibodies reactive with glutamic acid decarboxylase (GADA), islet antigen-2 (IA-2A) or insulin (IAA), alone or in combination. Control mothers (n=1419), who were islet autoantibody negative at delivery, were randomly selected and matched by age, parity and pregnancy sampling date. Mothers positive for GADA (92%), IA-2A (84%) or IAA (65%) at delivery had increased titers already evident in early pregnancy. Titers declined for GADA (p<0.0001), IA-2A (p<0.0001) and IAA (p<0.0001). Seroconversion during pregnancy was observed for GADA in 10 (8%), IA-2A in 3 (16%) and IAA in 37 (35%) mothers. It is concluded that non-diabetic mothers with islet autoantibodies at delivery had significantly higher titers during early pregnancy than at delivery. As the statistical power in the seroconverting mothers was insufficient, further studies are needed to determine if the risk for type 1 diabetes in the offspring differs between mothers who already had increased titers of islet autoantibodies during early pregnancy or acquired them during pregnancy.

The type 1 diabetes protective HLA DQB1*0602 allele is less frequent in gestational diabetes mellitus

We tested whether gestational diabetes mellitus (GDM) is associated with HLA-DQ genotypes. A total of 764 mothers with non-autoimmune (GAD65, insulinoma-associated protein 2 [IA-2] and insulin autoantibody-negative) GDM were ascertained between September 2000 and August 2004 in the population-based Diabetes Prediction in Skåne (DiPiS) study. HLA-DQB1 genotypes were determined in these mothers and in 1191 randomly selected non-diabetic control mothers also negative for islet autoantibodies. The data were analysed in relation to maternal age, country of birth, number of pregnancies/siblings and pregnancy weight gain. The frequency of type 1 diabetes high-risk HLA-DQ alleles (DQB1*0201, DQB1*0302) did not differ between GDM mothers and controls. In contrast, the low-risk DQB1*0602 allele was less prevalent (OR 0.64, 95% CI = 0.51-0.80, p = 0.0006) in GDM than in control mothers. The difference in DQB1*0602 frequency between GDM mothers and controls remained after multiple logistic regression analysis correcting for maternal age, country of birth, number of pregnancies/siblings and weight gain during pregnancy (OR 0.67, 95% CI 0.51-0.88, p = 0.009). The negative association between mothers who have non-autoimmune GDM and HLA-DQ*0602 suggest that this allele may protect not only from type 1 diabetes but also from GDM.

Relationship between increased relative birthweight and infections during pregnancy in children with a high-risk diabetes HLA genotype

Children with high-risk type 1 diabetes HLA genotype have increased risk of high relative birthweight (HrBW), while cord blood islet autoantibodies decrease the risk. As gestational infections may affect offspring type 1 diabetes risk, the aims were to test whether: (1) children of mothers reporting gestational infections have increased HrBW; (2) gestational infections explain islet autoantibody reduction of HrBW; and (3) gestational infections affect the association between HLA and HrBW. HLA genotypes and autoantibodies to glutamic acid decarboxylase, insulinoma-associated protein 2 and insulin were determined in cord blood of children born to non-diabetic mothers in the Diabetes Prediction in Skåne (DiPiS) study. Mothers reported gestational infections when the child was 2 months old. Fever or gastroenteritis during pregnancy was reported by 2,848/19,756 mothers (14%); 339 in more than one trimester. Children whose mothers reported infections had increased risk of HrBW (p = 0.0003), particularly in the absence of cord blood islet autoantibodies (interaction between HrBW, islet autoantibodies and infections, p = 0.0005). The effect on HrBW by high-risk HLA-DQ2/8 was aggravated by infections in more than one trimester (odds ratio [OR] = 5.24; p = 0.003) (interaction; p = 0.022). When infections were reported, cord blood islet autoantibodies decreased HrBW (OR = 0.34; p = 0.0002). This study revealed that: (1) gestational fever, gastroenteritis, or both, increased the risk of HrBW; (2) cord blood islet autoantibodies decreased the risk of HrBW only in combination with infections; and (3) infections aggravated the association between HLA-DQ2/8 and HrBW. These data suggest an interaction between HLA, gestational infections, islet autoantibodies and fetal growth.

Diabetes-associated HLA genotypes affect birthweight in the general population

The aim of our study was to test the hypothesis that HLA genotypes conferring risk of diabetes, cord blood autoantibodies, or both are associated with increased birthweight. HLA genotypes were determined in dried blood spots of cord blood from a total of 16,709 children born to healthy mothers in the Diabetes Prediction in Skåne (DiPiS) study, a population-based observational clinical investigation of newborn children. Children born to mothers with diabetes or gestational diabetes were excluded. Autoantibodies to glutamic acid decarboxylase (GAD65Ab) and insulinoma-associated protein 2 were determined in standard radioligand binding assays. Birthweight was adjusted for gestational age and divided into quartiles. The upper quartile was defined as high relative birthweight (HrBW) and the lower quartile as low relative birthweight (LrBW). Genotypes conferring risk of type 1 diabetes were strongly associated with relative birthweight (rBW) (p=0.01). The high-risk HLA-DQ2/8, DQ8/0604 and DQ8/X genotypes were associated with HrBW (odds ratio [OR] [95% CI]=1.20 [1.08-1.33], p=0.0006). The HLA-DQB1*0603 allele, which is negatively associated with type 1 diabetes, was also associated with HrBW (p=0.025), confirming a previous report on DQB1*0603-linked HLA-DR13. GAD65Ab were negatively associated with HrBW (OR [95% CI]=0.72 [0.56-0.93], p=0.01). Regression analysis showed that the HLA-associated increase in rBW was independent of confounding factors. HLA genotypes may be associated with intrauterine growth independent of type 1 diabetes risk. The epidemiological observation that high birthweight is a risk factor for type 1 diabetes could possibly result from a moderating effect on intrauterine growth of HLA genotypes conferring a high risk of diabetes.

Genetic and perinatal factors as risk for childhood type 1 diabetes.

The mechanisms by which gestational infections, blood incompatibility, birth weight, mother's age and other prenatal or neonatal events increase the risk for type 1 diabetes are not understood. Studies so far have been retrospective, and there is a lack of population-based prospective studies. The possibility of identifying children at type 1 diabetes risk among first-degree relatives has resulted in prospective studies aimed at identifying postnatal events associated with the appearance of autoantibody markers for type 1 diabetes and a possible later onset of diabetes. However, the majority (85%) of new onset type 1 diabetes children do not have a first-degree relative with the disease. Population-based studies are therefore designed to prospectively analyse pregnant mothers and their offspring. One such study is DiPiS (Diabetes Prediction in Skåne), which is examining a total of about 10,000 pregnancies expected every year in the Skåne (Scania) region of Sweden that has 1.1 million inhabitants. Blood samples from all mothers in this region are obtained during pregnancy and at the time of delivery. Cord blood is analysed for HLA high-risk alleles and for autoantibodies against the 65 kD isoform of glutamic acid decarboxylase (GADA), the protein tyrosine phosphatase-related IA-2 antigen (IA-2A) and insulin (IAA) as a measure of prenatal autoimmune exposure. Identifying high-risk children by genetic, autoimmune and gestational risk factors followed by prospective analyses will make it possible to test the hypothesis that gestational events may trigger beta cell autoimmunity as a prerequisite for childhood type 1 diabetes.