Analyses of regulatory CD4(+)CD25(+)FOXP3(+) T cells and observations from peripheral T cell subpopulation markers during the development of type 1 diabetes in children

Our aim was to study whether the aberrant amount or function of regulatory T cells is related to the development of type 1 diabetes (T1D) in children. We also set out to investigate the balance of different T cell subtype markers during the T1D autoimmune process. Treg cells were quantified with flow cytometric assay, and the suppression capacity was analysed with a carboxyfluorescein succinimidyl ester (CFSE)-based T cell suppression assay in children in various phases of T1D disease process and in healthy autoantibody-negative control children. The mRNA expression of different T cell subpopulation markers was analysed with real-time qPCR method. The proportion and suppression capacity of regulatory T cells were similar in seroconverted children at an early stage of beta cell autoimmunity and also in children with T1D when compared to healthy and autoantibody-negative children. Significant differences were observed in the mRNA expression of different T cell subpopulation markers in prediabetic children with multiple (2) autoantibodies and in children with newly diagnosed T1D when compared to the control children. In conclusion, there were no quantitative or functional differences in regulatory T cells between the case and control groups in any phase of the autoimmune process. Decreased mRNA expression levels of T cell subtype markers were observed in children with multiple islet autoantibodies and in those with newly diagnosed T1D, probably reflecting an exhaustion of the immune system after the strong immune activation during the autoimmune process or a generally aberrant immune response related to the progression of the disease.Peer reviewe

PCR inhibition in stool samples in relation to age of infants

Background: PCR is rapidly replacing traditional methods in diagnostic virus laboratories. PCR inhibitors,which are often present in clinical samples, may lead to false negative test results.Objectives: The aim was to study the presence of PCR inhibitors in stool samples collected from 3- to24-month old children.Study design: Total RNA fraction extracted from stool samples was spiked with a standardized amount ofSemliki Forest Virus RNA and amplified using specific PCR primers. The presence of PCR inhibitors wasdetected by a decrease in amplification rate compared to spiked water samples. Inhibition in differentage groups and dietary origin of PCR inhibitors were analyzed by comparing the samples taken duringexclusive and non-exclusive breastfeeding periods. The inactivation of PCR inhibitors was also assessed.Results: Complete inhibition was seen in 12% (13/108) and partial inhibition in 19% (21/108) of the samples.Inhibition was seen in none of the stool samples (0/31) taken from infants younger than 6 monthscompared to 17% of samples (13/77) taken from6 to 24 months old infants (p more common in younger age group. Addition of bovine serum albumin (BSA) into the reaction mixtureseliminated the effect of inhibitors leading to all samples being positive.Conclusions: PCR inhibitors are frequent in stool samples. They may originate from dietary componentsand can lead to false negative PCR results. The addition of BSA to the cDNA and PCR reactions proved tobe an easy and effective method for eliminating the inhibitory effect of these compounds

Early suppression of immune response pathways characterizes children with prediabetes in genome-wide gene expression profiling

Type 1 diabetes (T1D) is caused by autoimmune destruction of insulin-producing pancreatic p cells in the islets of Langerhans. Although defects in various T cell subsets have been linked to the disease pathogenesis, mechanisms initiating or enhancing the autoimmunity in prediabetes remain poorly understood. To unravel genes and molecular pathways affected by the diabetes-associated autoimmunity, we investigated transcriptomic profiles of prospective whole-blood samples from children who have developed T1D-associated autoantibodies and eventually clinical T1D. Gene-level investigation of the data showed systematic differential expression of 520 probesets. A network-based analysis revealed then a highly significant down-regulated network of genes involved in antigen presentation as well as T-cell receptor and insulin signaling. Finally, detection of dynamic changes in the affected pathways at the early or late phases of autoimmunity showed down-regulation of several novel T1D-associated pathways as well as known key components of immune response. The longitudinal genome-wide data generated in the present study allows the detection of dynamic changes relevant to the disease that may be completely missed in conventional cross-sectional studies or in genome-wide association studies. Taken together, our analysis showed systemic high-level repression of immune response pathways associated with T1D autoimmunity. (C) 2010 Elsevier Ltd. All rights reserved.</p

Hyperglycemia and lower diet quality in pregnant overweight women and increased infant size at birth and at 13 months of age - STEPS study

Conclusions: Maternal prepregnancy overweight increases risk of hyperglycemia in late-pregnancy and increased infant size at birth and 13 months possibly predisposing the infant to health risks later in life. (C) 2013 Elsevier Ireland Ltd. All rights reserved.</p

Analysis of pancreas tissue in a child positive for islet cell antibodies

Conclusions/interpretation These observations suggest that positivity for ICA alone, even when lasting for more than 1 year, is not associated with inflammatory changes in the islets. However, it is most likely that the pancreatic islets were infected by an enterovirus in this child

The Diet of Finnish Preschoolers

Verkkoversion ISBN 978-951-740-887-

Pandemrix® vaccination is not associated with increased risk of islet autoimmunity or type 1 diabetes in the TEDDY study children

Aims/hypothesis: During the A/H1N1 2009 (A/California/04/2009) pandemic, mass vaccination with a squalene-containing vaccine, Pandemrix®, was performed in Sweden and Finland. The vaccination was found to cause narcolepsy in children and young adults with the HLA-DQ 6.2 haplotype. The aim of this study was to investigate if exposure to Pandemrix® similarly increased the risk of islet autoimmunity or type 1 diabetes. Methods: In The Environmental Determinants of Diabetes in the Young (TEDDY) study, children are followed prospectively for the development of islet autoimmunity and type 1 diabetes. In October 2009, when the mass vaccination began, 3401 children at risk for islet autoimmunity and type 1 diabetes were followed in Sweden and Finland. Vaccinations were recorded and autoantibodies against insulin, GAD65 and insulinoma-associated protein 2 were ascertained quarterly before the age of 4 years and semi-annually thereafter. Results: By 5 August 2010, 2413 of the 3401 (71%) children observed as at risk for an islet autoantibody or type 1 diabetes on 1 October 2009 had been vaccinated with Pandemrix®. By 31 July 2016, 232 children had at least one islet autoantibody before 10 years of age, 148 had multiple islet autoantibodies and 96 had developed type 1 diabetes. The risk of islet autoimmunity was not increased among vaccinated children. The HR (95% CI) for the appearance of at least one islet autoantibody was 0.75 (0.55, 1.03), at least two autoantibodies was 0.85 (0.57, 1.26) and type 1 diabetes was 0.67 (0.42, 1.07). In Finland, but not in Sweden, vaccinated children had a lower risk of islet autoimmunity (0.47 [0.29, 0.75]), multiple autoantibodies (0.50 [0.28, 0.90]) and type 1 diabetes (0.38 [0.20, 0.72]) compared with those who did not receive Pandemrix®. The analyses were adjusted for confounding factors. Conclusions/interpretation: Children with an increased genetic risk for type 1 diabetes who received the Pandemrix® vaccine during the A/H1N1 2009 pandemic had no increased risk of islet autoimmunity, multiple islet autoantibodies or type 1 diabetes. In Finland, the vaccine was associated with a reduced risk of islet autoimmunity and type 1 diabetes.</p