A longitudinal plasma lipidomics dataset from children who developed islet autoimmunity and type 1 diabetes

Early prediction and prevention of type 1 diabetes (T1D) are currently unmet medical needs. Previous metabolomics studies suggest that children who develop T1D are characterised by a distinct metabolic profile already detectable during infancy, prior to the onset of islet autoimmunity. However, the specificity of persistent metabolic disturbances in relation T1D development has not yet been established. Here, we report a longitudinal plasma lipidomics dataset from (1) 40 children who progressed to T1D during follow-up, (2) 40 children who developed single islet autoantibody but did not develop T1D and (3) 40 matched controls (6 time points: 3, 6, 12, 18, 24 and 36 months of age). This dataset may help other researchers in studying age-dependent progression of islet autoimmunity and T1D as well as of the age-dependence of lipidomic profiles in general. Alternatively, this dataset could more broadly used for the development of methods for the analysis of longitudinal multivariate data.

Sex as a determinant of type 1 diabetes at diagnosis

OBJECTIVE

The present study tested the hypothesis that girls have a more aggressive disease process than boys at the diagnosis of type 1 diabetes (T1D).

METHODS

Demographic and clinical characteristics, the humoral autoantibody profile, and the genetic risk assessed by the presence of human leukocyte antigen DR-DQ haplotypes were analyzed in terms of sex in 4993 children and adolescents diagnosed with T1D between January 2003 and December 2016.

RESULTS

A clear male preponderance (56.6%) was observed in our cohort and boys were significantly older than girls at clinical diagnosis (mean 8.3 vs 7.7 years, P < .001). Age-adjusted analyses showed a poorer metabolic decompensation in girls than boys at diagnosis. Boys tested more often positive for autoantibodies against insulin autoantibodies (P = .008), islet antigen-2 autoantibodies (P = .033), and zinc transporter 8 autoantibodies (P = .027), whereas girls had a higher frequency of glutamic acid decarboxylase autoantibodies (GADA) (P < .001) and higher GADA (P < .001) and islet cell antibody titers (P = .001). We did not find any significant differences in the genetic risk profile between girls and boys.

CONCLUSIONS

Our data show that the metabolic derangement is more severe in girls already at diagnosis of T1D and this finding is independent of age. The immunologic aggressiveness of the disease is more variable as the predominance of different autoantibodies varies between sexes with a higher frequency of GADA in girls, while the 3 other biochemical autoantibodies were more common in boys.

Class II HLA Genotype Association With First-Phase Insulin Response Is Explained by Islet Autoantibodies

CONTEXT

A declining first-phase insulin response (FPIR) is characteristic of the disease process leading to clinical type 1 diabetes. It is not known whether reduced FPIR depends on class II human leukocyte antigen (HLA) genotype, islet autoimmunity, or both.

OBJECTIVE

To dissect the role of class II HLA DR-DQ genotypes and biochemical islet autoantibodies in the compromised FPIR.

DESIGN, SETTING, PARTICIPANTS

A total of 438 children with defined HLA DR-DQ genotype in the prospective Finnish Type 1 Diabetes Prediction and Prevention Study were analyzed for FPIR in a total of 1149 intravenous glucose tolerance tests and were categorized by their HLA DR-DQ genotype and the number of biochemical islet autoantibodies at the time of the first FPIR. Age-adjusted hierarchical linear mixed models were used to analyze repeated measurements of FPIR.

MAIN OUTCOME MEASURE

The associations between class II HLA DR-DQ genotype, islet autoantibody status, and FPIR.

RESULTS

A strong association between the degree of risk conferred by HLA DR-DQ genotype and positivity for islet autoantibodies existed (P < 0.0001). FPIR was inversely associated with the number of biochemical autoantibodies (P < 0.0001) irrespective of HLA DR-DQ risk group. FPIR decreased over time in children with multiple autoantibodies and increased in children with no biochemical autoantibodies (P < 0.0001 and P = 0.0013, respectively).

CONCLUSIONS

The class II HLA DR-DQ genotype association with FPIR was secondary to the association between HLA and islet autoimmunity. Declining FPIR was associated with positivity for multiple islet autoantibodies irrespective of class II HLA DR-DQ genotype.

Effector T Cell Resistance to Suppression and STAT3 Signaling during the Development of Human Type 1 Diabetes

Dysregulation of regulatory T cell (Treg)-mediated suppression and, in particular, resistance of CD4⁺ effector T cells (Teffs) to suppression have been implicated in the pathogenesis of human type 1 diabetes (T1D). However, the mechanistic basis behind this resistance and the time frame during which it develops in relation to the onset of clinical T1D remain unclear. In this study, we analyzed the capacity of peripheral blood Teffs isolated both from patients with T1D and from prediabetic at-risk subjects positive for multiple diabetes-associated autoantibodies (AAb⁺) to be suppressed by Tregs. Because STAT3 activation through IL-6 has previously been implicated in mediating Teff resistance, we also investigated the surface expression of IL-6R as well as IL-6- and TCR-mediated phosphorylation of STAT3 in T cells from our study subjects. Teff resistance to suppression was observed both in patients with newly diagnosed and long-standing T1D but not in AAb⁺ subjects and was shown to be STAT3 dependent. No alterations in IL-6R expression or IL-6-mediated STAT3 activation were observed in T cells from patients with T1D or AAb⁺ subjects. However, faster STAT3 activation after TCR stimulation without concomitant increase in IL-6 expression was observed in T cells from patients with T1D. These experiments suggest that Teff resistance in T1D patients is STAT3 dependent but not directly linked with the capacity of Teffs to produce or respond to IL-6. In conclusion, Teff resistance to Treg-mediated suppression is likely a feature of disease progression in human T1D and can potentially be targeted by immune therapies that block STAT3 activation.

Coxsackievirus B1 infections are associated with the initiation of insulin-driven autoimmunity that progresses to type 1 diabetes

AIMS/HYPOTHESIS

Islet autoimmunity usually starts with the appearance of autoantibodies against either insulin (IAA) or GAD65 (GADA). This categorises children with preclinical type 1 diabetes into two immune phenotypes, which differ in their genetic background and may have different aetiology. The aim was to study whether Coxsackievirus group B (CVB) infections, which have been linked to the initiation of islet autoimmunity, are associated with either of these two phenotypes in children with HLA-conferred susceptibility to type 1 diabetes.

METHODS

All samples were from children in the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) study. Individuals are recruited to the DIPP study from the general population of new-born infants who carry defined HLA genotypes associated with susceptibility to type 1 diabetes. Our study cohort included 91 children who developed IAA and 78 children who developed GADA as their first appearing single autoantibody and remained persistently seropositive for islet autoantibodies, along with 181 and 151 individually matched autoantibody negative control children, respectively. Seroconversion to positivity for neutralising antibodies was detected as the surrogate marker of CVB infections in serial follow-up serum samples collected before and at the appearance of islet autoantibodies in each individual.

RESULTS

CVB1 infections were associated with the appearance of IAA as the first autoantibody (OR 2.4 [95% CI 1.4, 4.2], corrected p = 0.018). CVB5 infection also tended to be associated with the appearance of IAA, however, this did not reach statistical significance (OR 2.3, [0.7, 7.5], p = 0.163); no other CVB types were associated with increased risk of IAA. Children who had signs of a CVB1 infection either alone or prior to infections by other CVBs were at the highest risk for developing IAA (OR 5.3 [95% CI 2.4, 11.7], p < 0.001). None of the CVBs were associated with the appearance of GADA.

CONCLUSIONS/INTERPRETATION

CVB1 infections may contribute to the initiation of islet autoimmunity being particularly important in the insulin-driven autoimmune process.

Exocrine pancreas function decreases during the progression of the beta-cell damaging process in young prediabetic children

OBJECTIVE

The function of the exocrine pancreas is decreased in patients with type 1 diabetes but it is not known when this defect develops. The current study set out to determine whether the reduced exocrine function becomes manifest after the initiation of islet autoimmunity.

METHODS

The study was nested in the prospective Type 1 Diabetes Prediction and Prevention study where children with human leukocyte antigen (HLA)-conferred susceptibility are observed from birth. Elastase-1 levels were analyzed from stool samples collected at the time of seroconversion to islet autoantibody positivity and at diagnosis of type 1 diabetes, as well as from samples taken from matched control children of similar age.

RESULTS

Elastase levels were lower in case children at the time of the diagnosis of diabetes when compared to the control children. However, elastase concentrations did not differ between cases and controls at the time when autoantibodies appeared.

CONCLUSION

The results suggest that the defect in the exocrine function develops after the appearance of islet autoantibodies. Further studies are needed to assess whether reduced elastase levels predict rapid progression of islet autoimmunity to clinical disease.

Early fecal microbiota composition in children who later develop celiac disease and associated autoimmunity

OBJECTIVES

Several studies have reported that the intestinal microbiota composition of celiac disease (CD) patients differs from healthy individuals. The possible role of gut microbiota in the pathogenesis of the disease is, however, not known. Here, we aimed to assess the possible differences in early fecal microbiota composition between children that later developed CD and healthy controls matched for age, sex and HLA risk genotype.

MATERIALS AND METHODS

We used 16S rRNA gene sequencing to examine the fecal microbiota of 27 children with high genetic risk of developing CD. Nine of these children developed the disease by the age of 4 years. Stool samples were collected at the age of 9 and 12 months, before any of the children had developed CD. The fecal microbiota composition of children who later developed the disease was compared with the microbiota of the children who did not have CD or associated autoantibodies at the age of 4 years. Delivery mode, early nutrition, and use of antibiotics were taken into account in the analyses.

RESULTS

No statistically significant differences in the fecal microbiota composition were found between children who later developed CD (n = 9) and the control children without disease or associated autoantibodies (n = 18).

CONCLUSIONS

Based on our results, the fecal microbiota composition at the age of 9 and 12 months is not associated with the development of CD. Our results, however, do not exclude the possibility of duodenal microbiota changes or a later microbiota-related trigger for the disease.

Ketoacidosis at diagnosis of type 1 diabetes: Effect of prospective studies with newborn genetic screening and follow up of risk children

We studied the frequency of diabetic ketoacidosis (DKA) in children at diagnosis of type 1 diabetes (T1D) in a region where newborn infants have since 1995 been recruited for genetic screening for human leukocyte antigen (HLA)-conferred disease susceptibility and prospective follow up. The aim was to study whether participation in newborn screening and follow up affected the frequency of DKA, and to follow the time trends in DKA frequency. We first included children born in Oulu University Hospital since 1995 when the prospective studies have been ongoing and diagnosed with T1D <15 years by 2015 (study cohort 1, n = 517). Secondly, we included all children diagnosed with T1D <15 years in this center during 2002-2014 (study cohort 2, n = 579). Children who had an increased genetic risk for T1D and participated in prospective follow up had low frequency of DKA at diagnosis (5.0%). DKA was present in 22.7% of patients not screened for genetic risk, 26.7% of those who were screened but had not an increased risk and 23.4% of children with increased genetic risk but who were not followed up. In study cohort 2 the overall frequency of DKA was 18.5% (13.0% in children <5 years, 14.0% in children 5-10 years and 28.6% in children ≥10 years at diagnosis; P<.001). In children <2 years the frequency of DKA was 17.1%. Participation in prospective follow-up studies reduces the frequency of DKA in children at diagnosis of T1D, but genetic screening alone does not decrease DKA risk.

Transglutaminase antibodies and celiac disease in children with type 1 diabetes and in their family members

OBJECTIVES

We set out to determine the prevalence of tissue transglutaminase antibodies (anti-tTG) and celiac disease (CD) in children with newly diagnosed type 1 diabetes (T1D) and their first-degree relatives (FDR). The hypothesis was that the individuals with both diabetes and CD form a distinct subgroup in terms of human leukocyte antigen (HLA) class II genetics, islet autoantibodies, and clinical characteristics at diabetes diagnosis.

SUBJECTS AND METHODS

This population-based observational study included 745 index children with T1D and their 2692 FDR from the Finnish Pediatric Diabetes Register. CD was ascertained by registers, patient records, and screening anti-tTG positive individuals for further testing.

RESULTS

Among the index children, 4.8% had anti-tTG at diabetes diagnosis, and at the end of the study 3.2% had CD. Among the relatives, 2.9% had anti-tTG (4.8% mothers, 2.4% fathers, and 2.1% siblings), and 2.5% had CD (4.6% mothers, 2.1% fathers, and 1.4% siblings). Anti-tTG and CD associated with the HLA DR3-DQ2 haplotype. The usual female predominance of CD patients was observed in relatives (70%) but not among index children (46%). The index children with both diseases had a lower number of detectable islet autoantibodies than those with diabetes alone.

CONCLUSIONS

The children with double diagnosis differed from those with diabetes alone in HLA genetics, humoral islet autoimmunity directed against fewer antigens, and in the lack of usual female preponderance among CD patients. Compared with 61% of the anti-tTG positive relatives, only 36% of anti-tTG positive index children developed CD implicating transient anti-tTG positivity at diagnosis of T1D.

Early childhood infections precede development of beta-cell autoimmunity and type 1 diabetes in children with HLA-conferred disease risk

BACKGROUND

The etiology of type 1 diabetes (T1D) is largely unknown. Infections and microbial exposures are believed to play a role in the pathogenesis and in the development of islet autoimmunity in genetically susceptible individuals.

OBJECTIVE

To assess the relationships between early childhood infections, islet autoimmunity, and progression to T1D in genetically predisposed children.

METHODS

Children with human leukocyte antigen (HLA)-conferred disease susceptibility (N=790; 51.5% males) from Finland (n = 386), Estonia (n = 322), and Russian Karelia (n = 82) were observed from birth up to the age of 3 years. Children attended clinical visits at the age of 3, 6, 12, 18, 24, and 36 months. Serum samples for analyzing T1D-associated autoimmune markers were collected and health data recorded during the visits.

RESULTS

Children developing islet autoimmunity (n = 46, 5.8%) had more infections during the first year of life (3.0 vs 3.0, mean rank 439.1 vs 336.2; P = .001) and their first infection occurred earlier (3.6 vs 5.0 months; P = .005) than children with no islet autoimmunity. By May 2016, 7 children (0.9%) had developed T1D (progressors). Compared with non-diabetic children, T1D progressors were younger at first infection (2.2 vs 4.9 months; P = .004) and had more infections during the first 2 years of life (during each year 6.0 vs 3.0; P = .001 and P = .027, respectively). By 3 years of age, the T1D progressors had twice as many infections as the other children (17.5 vs 9.0; P = .006).

CONCLUSIONS

Early childhood infections may play an important role in the pathogenesis of T1D. Current findings may reflect either differences in microbial exposures or early immunological aberrations making diabetes-prone children more susceptible to infections.

Primary islet autoantibody at initial seroconversion and autoantibodies at diagnosis of type 1 diabetes as markers of disease heterogeneity

OBJECTIVE

The relationship between patterns of islet autoantibodies at diagnosis and specificity of the first islet autoantibody at the initiation of autoimmunity was analyzed with the aim of identifying patterns informative of the primary autoantibodies.

METHODS

Information about a single first autoantibody at seroconversion and autoantibody data at diagnosis were available for 128 children participating in the follow-up cohort of the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) study. Autoantibody data at diagnosis and genotyping results were also obtained from children in the Finnish Pediatric Diabetes Register (FPDR).

RESULTS

Insulin autoantibodies (IAA) were the most common primary antibodies (N = 68), followed by those for glutamic acid decarboxylase (GADA; N = 38), IA-2 antigen (IA-2A; N = 13), and zinc transporter 8 (ZnT8A; N = 9), whereas at diagnosis, IA-2A were most frequent (N = 103), followed by IAA (N = 78), ZnT8A (N = 73), and GADA (N = 71). Accordingly, the presence of many specific autoantibodies at diagnosis was due to the secondary antibodies appearing after primary antibodies, and in some cases, the primary autoantibody, most often IAA, had already disappeared at the time of diagnosis. Many of the autoantibody combinations present at diagnosis could be assembled into groups associated with either IAA or GADA as first autoantibodies. These combinations, in children diagnosed below the age of 10 years in the FPDR, were found to be strongly associated with risk genotypes in either INS (IAA first) or IKZF4-ERBB3 (GADA first) genes.

CONCLUSIONS

Autoantibody patterns at diagnosis may be informative on primary autoantibodies initiating autoimmunity in young children developing type 1 diabetes.

Enterovirus-associated changes in blood transcriptomic profiles of children with genetic susceptibility to type 1 diabetes

AIMS/HYPOTHESIS

Enterovirus infections have been associated with the development of type 1 diabetes in multiple studies, but little is known about enterovirus-induced responses in children at risk for developing type 1 diabetes. Our aim was to use genome-wide transcriptomics data to characterise enterovirus-associated changes in whole-blood samples from children with genetic susceptibility to type 1 diabetes.

METHODS

Longitudinal whole-blood samples (356 samples in total) collected from 28 pairs of children at increased risk for developing type 1 diabetes were screened for the presence of enterovirus RNA. Seven of these samples were detected as enterovirus-positive, each of them collected from a different child, and transcriptomics data from these children were analysed to understand the individual-level responses associated with enterovirus infections. Transcript clusters with peaking or dropping expression at the time of enterovirus positivity were selected as the enterovirus-associated signals.

RESULTS

Strong signs of activation of an interferon response were detected in four children at enterovirus positivity, while transcriptomic changes in the other three children indicated activation of adaptive immune responses. Additionally, a large proportion of the enterovirus-associated changes were specific to individuals. An enterovirus-induced signature was built using 339 genes peaking at enterovirus positivity in four of the children, and 77 of these genes were also upregulated in human peripheral blood mononuclear cells infected in vitro with different enteroviruses. These genes separated the four enterovirus-positive samples clearly from the remaining 352 blood samples analysed.

CONCLUSIONS/INTERPRETATION

We have, for the first time, identified enterovirus-associated transcriptomic profiles in whole-blood samples from children with genetic susceptibility to type 1 diabetes. Our results provide a starting point for understanding the individual responses to enterovirus infections in blood and their potential connection to the development of type 1 diabetes.

DATA AVAILABILITY

The datasets analysed during the current study are included in this published article and its supplementary information files ( www.btk.fi/research/computational-biomedicine/1234-2 ) or are available from the Gene Expression Omnibus (GEO) repository (accession GSE30211).

Effect of Hydrolyzed Infant Formula vs Conventional Formula on Risk of Type 1 Diabetes: The TRIGR Randomized Clinical Trial

IMPORTANCE

Early exposure to complex dietary proteins may increase the risk of type 1 diabetes in children with genetic disease susceptibility. There are no intact proteins in extensively hydrolyzed formulas.

OBJECTIVE

To test the hypothesis that weaning to an extensively hydrolyzed formula decreases the cumulative incidence of type 1 diabetes in young children.

DESIGN, SETTING, AND PARTICIPANTS

An international double-blind randomized clinical trial of 2159 infants with human leukocyte antigen-conferred disease susceptibility and a first-degree relative with type 1 diabetes recruited from May 2002 to January 2007 in 78 study centers in 15 countries; 1081 were randomized to be weaned to the extensively hydrolyzed casein formula and 1078 to a conventional formula. The follow-up of the participants ended on February 28, 2017.

INTERVENTIONS

The participants received either a casein hydrolysate or a conventional adapted cow's milk formula supplemented with 20% of the casein hydrolysate. The minimum duration of study formula exposure was 60 days by 6 to 8 months of age.

MAIN OUTCOMES AND MEASURES

Primary outcome was type 1 diabetes diagnosed according to World Health Organization criteria. Secondary outcomes included age at diabetes diagnosis and safety (adverse events).

RESULTS

Among 2159 newborn infants (1021 female [47.3%]) who were randomized, 1744 (80.8%) completed the trial. The participants were observed for a median of 11.5 years (quartile [Q] 1-Q3, 10.2-12.8). The absolute risk of type 1 diabetes was 8.4% among those randomized to the casein hydrolysate (n = 91) vs 7.6% among those randomized to the conventional formula (n = 82) (difference, 0.8% [95% CI, -1.6% to 3.2%]). The hazard ratio for type 1 diabetes adjusted for human leukocyte antigen risk group, duration of breastfeeding, duration of study formula consumption, sex, and region while treating study center as a random effect was 1.1 (95% CI, 0.8 to 1.5; P = .46). The median age at diagnosis of type 1 diabetes was similar in the 2 groups (6.0 years [Q1-Q3, 3.1-8.9] vs 5.8 years [Q1-Q3, 2.6-9.1]; difference, 0.2 years [95% CI, -0.9 to 1.2]). Upper respiratory infections were the most common adverse event reported (frequency, 0.48 events/year in the hydrolysate group and 0.50 events/year in the control group).

CONCLUSIONS AND RELEVANCE

Among infants at risk for type 1 diabetes, weaning to a hydrolyzed formula compared with a conventional formula did not reduce the cumulative incidence of type 1 diabetes after median follow-up for 11.5 years. These findings do not support a need to revise the dietary recommendations for infants at risk for type 1 diabetes.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00179777.

Live attenuated enterovirus vaccine (OPV) is not associated with islet autoimmunity in children with genetic susceptibility to type 1 diabetes: prospective cohort study

AIMS/HYPOTHESIS

Animal and human studies have implied that enterovirus infections may modulate the risk of islet autoimmunity and type 1 diabetes. We set out to assess whether serial administration of live oral poliovirus vaccine (OPV) in early life can influence the initiation of islet autoimmunity in a cohort of genetically predisposed children.

METHODS

OPV was administered to 64 children and a further 251 children received inactivated poliovirus vaccine (IPV). The emergence of type 1 diabetes-associated autoantibodies in serum (autoantibodies to GAD, insulinoma-associated protein 2, insulin and islet cells) was monitored during prospective follow-up. Stool and serum samples were collected for enterovirus detection by RT-PCR.

RESULTS

Administration of OPV increased enterovirus detected in stool samples from 11.3% to 38.9% (p < 0.001) during the first year of life. During the follow-up (median 11.0 years), at least one autoantibody was detected in 17.2% of children vaccinated with OPV and 19.1% with IPV (p = 0.723). At least two autoantibodies were observed in 3.1% and 6.8% of children, respectively (p = 0.384).

CONCLUSIONS/INTERPRETATION

Replication of attenuated poliovirus strains in gut mucosa is not associated with an increased risk of islet autoimmunity.

TRIAL REGISTRATION

ClinicalTrials.gov : NCT02961595.

Infant Feeding in Relation to the Risk of Advanced Islet Autoimmunity and Type 1 Diabetes in Children With Increased Genetic Susceptibility: A Cohort Study

Breastfeeding, age at introduction of foods, and food diversity in infancy were studied for associations with advanced islet autoimmunity and type 1 diabetes. During 1996--2004, a total of 5,915 newborns with human leukocyte antigen-conferred susceptibility to type 1 diabetes were enrolled in the prospective Finnish Type 1 Diabetes Prediction and Prevention Nutrition Study. Children were assessed at intervals of 3-12 months for the appearance of 4 types of islet autoantibodies and type 1 diabetes up to the age of 15 years. Survival models indicated the 3 variables of interest were not associated with advanced islet autoimmunity or type 1 diabetes in the cohort. Early introduction of solid foods was associated with increased risk of advanced islet autoimmunity in children up to age 3 years (for <3 months vs. >4 months, hazard ratio = 2.33, 95% confidence interval: 1.39, 3.91; for 3-4 months vs. >4 months, hazard ratio = 2.18; 95% confidence interval: 1.38, 3.47) but not in longer follow-up (P for interaction = 0.046). Similar results were observed for age at introduction of roots, cereals, egg, and meat relative to risk of advanced islet autoimmunity. No consistent, long-term associations between infant feeding and advanced islet autoimmunity or type 1 diabetes were observed.

Serum carotenoid and tocopherol concentrations and risk of asthma in childhood: a nested case-control study

BACKGROUND

The antioxidant hypothesis regarding the risk of asthma in childhood has resulted in inconsistent findings. Some data indicate that the role of antioxidants in childhood asthma risk may have a critical time window of effect, but only a well-designed longitudinal cohort study can clarify this hypothesis.

OBJECTIVE

To study the longitudinal associations between serum carotenoid and tocopherol concentrations during the first 4 years of life and asthma risk by the age of 5 years.

METHODS

Based on a case-control design nested within a Finnish birth cohort, 146 asthma cases were matched to 270 controls on birth time, sex, genetic risk, and birth place. Non-fasting blood samples were collected at the ages of 1, 1.5, 2, 3, and 4 years and serum carotenoids and tocopherols were analysed. Parents reported the presence and age at start of persistent doctor-diagnosed asthma in the child at the age of 5 years. Data analyses were conducted using generalized estimating equations.

RESULTS

We did not find strong associations between serum carotenoids and tocopherols and the risk of asthma based on age-specific and longitudinal analyses. Both lower and higher quarters of α-carotene and γ-tocopherol increased the risk of asthma.

CONCLUSIONS

The current findings do not support the suggestion that the increased prevalence of asthma may be a consequence of decreased intake of antioxidant nutrients. Moreover, we did not confirm any critical time window of impact of antioxidants on asthma risk. Replication of these findings in similar longitudinal settings will strengthen this evidence base.

HLA and non-HLA genes and familial predisposition to autoimmune diseases in families with a child affected by type 1 diabetes

Genetic predisposition could be assumed to be causing clustering of autoimmunity in individuals and families. We tested whether HLA and non-HLA loci associate with such clustering of autoimmunity. We included 1,745 children with type 1 diabetes from the Finnish Pediatric Diabetes Register. Data on personal or family history of autoimmune diseases were collected with a structured questionnaire and, for a subset, with a detailed search for celiac disease and autoimmune thyroid disease. Children with multiple autoimmune diseases or with multiple affected first- or second-degree relatives were identified. We analysed type 1 diabetes related HLA class II haplotypes and genotyped 41 single nucleotide polymorphisms (SNPs) outside the HLA region. The HLA-DR4-DQ8 haplotype was associated with having type 1 diabetes only whereas the HLA-DR3-DQ2 haplotype was more common in children with multiple autoimmune diseases. Children with multiple autoimmune diseases showed nominal association with RGS1 (rs2816316), and children coming from an autoimmune family with rs11711054 (CCR3-CCR5). In multivariate analyses, the overall effect of non-HLA SNPs on both phenotypes was evident, associations with RGS1 and CCR3-CCR5 region were confirmed and additional associations were implicated: NRP1, FUT2, and CD69 for children with multiple autoimmune diseases. In conclusion, HLA-DR3-DQ2 haplotype and some non-HLA SNPs contribute to the clustering of autoimmune diseases in children with type 1 diabetes and in their families.

Vitamin D intake during the first 4 years and onset of asthma by age 5: A nested case-control study

BACKGROUND

Early-life vitamin D intake has been linked to asthma risk in childhood, but the role of longitudinal vitamin D exposure has not been previously evaluated. We investigated the association between vitamin D intake during the first 4 years of life and asthma risk by age 5.

METHODS

Within a Finnish population-based birth cohort, 182 incident asthma cases were matched to 728 controls on sex, genetic risk for type 1 diabetes, delivery hospital, and time of birth. Vitamin D intake was assessed by age-specific 3 day food records. Parents completed a validated version of the International Study of Asthma and Allergies in Childhood questionnaire at 5 years.

RESULTS

At 3 months, supplements were the main source of vitamin D intake; intake from foods increased from 3 months on, mainly from fortified milk products. Vitamin D intake at each specific age was associated with an increased risk of any asthma, atopic, and non-atopic asthma, but only intake at 1 and 2 years was statistically significantly associated with asthma. Longitudinal vitamin D intake was associated with an increased risk of asthma (OR 1.24; 95%CI 1.00-1.53).

CONCLUSIONS

Increased vitamin D intake in childhood, particularly intake at 1 and 2 years of age, may increase risk of childhood asthma. This might reflect a true effect or residual confounding by lifestyle or environmental factors. Repeated assessment of vitamin D intake allowed evaluation of the longitudinal and age-dependent impact of vitamin D on the risk of asthma. Further longitudinal studies are required to confirm or question these findings.

Imbalance of bacteriome profiles within the Finnish Diabetes Prediction and Prevention study: Parallel use of 16S profiling and virome sequencing in stool samples from children with islet autoimmunity and matched controls

BACKGROUND

We set out to explore associations between the stool bacteriome profiles and early-onset islet autoimmunity, taking into account the interactions with the virus component of the microbiome.

METHODS

Serial stool samples were longitudinally collected from 18 infants and toddlers with early-onset islet autoimmunity (median age 17.4 months) followed by type 1 diabetes, and 18 tightly matched controls from the Finnish Diabetes Prediction and Prevention (DIPP) cohort. Three stool samples were analyzed, taken 3, 6, and 9 months before the first detection of serum autoantibodies in the case child. The risk of islet autoimmunity was evaluated in relation to the composition of the bacteriome 16S rDNA profiles assessed by mass sequencing, and to the composition of DNA and RNA viromes.

RESULTS

Four operational taxonomic units were significantly less abundant in children who later on developed islet autoimmunity as compared to controls-most markedly the species of Bacteroides vulgatus and Bifidobacterium bifidum. The alpha or beta diversity, or the taxonomic levels of bacterial phyla, classes or genera, showed no differences between cases and controls. A correlation analysis suggested a possible relation between CrAssphage signals and quantities of Bacteroides dorei. No apparent associations were seen between development of islet autoimmunity and sequences of yet unknown origin.

CONCLUSIONS

The results confirm previous findings that an imbalance within the prevalent Bacteroides genus is associated with islet autoimmunity. The detected quantitative relation of the novel "orphan" bacteriophage CrAssphage with a prevalent species of the Bacteroides genus may exemplify possible modifiers of the bacteriome.

Avoidance of Cow's Milk-Based Formula for At-Risk Infants Does Not Reduce Development of Celiac Disease: A Randomized Controlled Trial

BACKGROUND & AIMS

Feeding during the first months of life might affect risk for celiac disease. Individuals with celiac disease or type 1 diabetes have been reported to have high titers of antibodies against cow's milk proteins. Avoidance of cow's milk-based formula for infants with genetic susceptibility for type 1 diabetes reduced the cumulative incidence of diabetes-associated autoantibodies. We performed a randomized controlled trial in the same population to study whether weaning to an extensively hydrolyzed formula reduced the risk of celiac disease autoimmunity or celiac disease.

METHODS

We performed a double-blind controlled trial of 230 infants with HLA-defined predisposition to type 1 diabetes and at least 1 family member with type 1 diabetes. The infants were randomly assigned to groups fed a casein hydrolysate formula (n = 113) or a conventional formula (control, n = 117) whenever breast milk was not available during the first 6-8 months of life. Serum samples were collected over a median time period of 10 years and analyzed for antibodies to tissue transglutaminase (anti-TG2A) using a radiobinding assay, to endomysium using an immunofluorescence assay, and antibodies to a deamidated gliadine peptide using an immunofluorometry assay. Duodenal biopsies were collected if levels of anti-TG2A exceeded 20 relative units. Cow's milk antibodies were measured during the first 2 years of life.

RESULTS

Of the 189 participants analyzed for anti-TG2A, 25 (13.2%) tested positive. Of the 230 study participants observed, 10 (4.3%) were diagnosed with celiac disease. We did not find any significant differences at the cumulative incidence of anti-TG2A positivity (hazard ratio, 1.14; 95% confidence interval, 0.51-2.54) or celiac disease (hazard ratio, 4.13; 95% confidence interval, 0.81-21.02) between the casein hydrolysate and cow's milk groups. Children who developed celiac disease had increased titers of cow's milk antibodies before the appearance of anti-TG2A or celiac disease.

CONCLUSIONS

In a randomized controlled trial of 230 infants with genetic risk factors for celiac disease, we did not find evidence that weaning to a diet of extensively hydrolyzed formula compared with cow's milk-based formula would decrease the risk for celiac disease later in life. Increased titers of cow's milk antibody before anti-TG2A and celiac disease indicates that subjects with celiac disease might have increased intestinal permeability in early life. ClinicalTrials.gov Number: NCT00570102.

Maternal fatty acid intake during pregnancy and the development of childhood overweight: a birth cohort study

BACKGROUND

Maternal diet during pregnancy may contribute to the risk of offspring adiposity.

OBJECTIVES

The objective of the study is to explore the associations between maternal antenatal dietary fatty acid intake and the risk of offspring overweight and obesity at the ages of 2 to 7 years.

METHODS

In a prospective Finnish birth cohort with 3807 mother-child pairs, maternal diet in late pregnancy was assessed with a food frequency questionnaire. Intakes of total fatty acids and individual saturated, monounsaturated and polyunsaturated fatty acids (PUFAs) were calculated. Generalized estimating equation models were used to study the associations of maternal dietary variables with repeatedly measured offspring overweight and obesity.

RESULTS

In girls, maternal intake ratio of n-6:n-3 PUFAs had a U-shaped association with obesity (adjusted OR for the lowest 2.0 [95% CI 1.27-3.20] and the highest 1.7 [1.03-2.73] vs. the two middle quartiles of n-6:n-3 PUFAs, p = 0.01). In boys, arachidonic acid (20:4n-6): docosahexaenoic acid + eicosapentaenoic acid ratio was associated with obesity (adjusted OR for the lowest 1.0 [0.60-1.57] and the highest 0.5 [0.26-0.88] vs. the two middle quartiles, p = 0.02). Saturated fatty acids and monounsaturated fatty acids were not associated with overweight or obesity in either sex.

CONCLUSIONS

Maternal intakes of PUFAs in late pregnancy were associated with risk of later obesity differently in girls and boys.

Characterisation of rapid progressors to type 1 diabetes among children with HLA-conferred disease susceptibility

AIMS/HYPOTHESIS

In this study, we aimed to characterise rapid progressors to type 1 diabetes among children recruited from the general population, on the basis of HLA-conferred disease susceptibility.

METHODS

We monitored 7410 HLA-predisposed children participating in the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) study for the development of beta cell autoimmunity and type 1 diabetes from birth over a median follow-up time of 16.2 years (range 0.9-21.1 years). Islet cell antibodies (ICA) and autoantibodies to insulin (IAA), GAD (GADA) and islet antigen 2 (IA-2A) were assessed as markers of beta cell autoimmunity. Rapid progression was defined as progression to clinical type 1 diabetes within 1.5 years of autoantibody seroconversion. We analysed the association between rapid progression and demographic and autoantibody characteristics as well as genetic markers, including 25 non-HLA SNPs predisposing to type 1 diabetes.

RESULTS

Altogether, 1550 children (21%) tested positive for at least one diabetes-associated autoantibody in at least two samples, and 248 (16%) of seroconverters progressed to type 1 diabetes by the end of 2015. The median time from seroconversion to diagnosis was 0.51 years in rapid progressors (n = 42, 17%) and 5.4 years in slower progressors. Rapid progression was observed both among young (<5 years) and early pubertal children (>7 years), resulting in a double-peak distribution of seroconversion age. Compared with slower progressors, rapid progressors had a higher frequency of positivity for multiple (≥2) autoantibodies and had higher titres of ICA, IAA and IA-2A at seroconversion, and there was a higher prevalence of the secretor genotype in the FUT2 gene among those carrying the high-risk HLA genotype. Compared with autoantibody-positive non-progressors, rapid progressors were younger, were more likely to carry the high-risk HLA genotype and a predisposing SNP in the PTPN22 gene, had higher frequency of ICA, IAA, GADA and IA-2A positivity and multipositivity, and had higher titres of all four autoantibodies at seroconversion.

CONCLUSIONS/INTERPRETATION

At seroconversion, individuals with rapid progression to type 1 diabetes were characterised by a younger age, higher autoantibody titres, positivity for multiple autoantibodies and higher prevalence of a FUT2 SNP. The double-peak profile for seroconversion age among the rapid progressors demonstrates for the first time that rapid progression may take place not only in young children but also in children in early puberty. Rapid progressors might benefit from careful clinical follow-up and early preventive measures.