A study of 51 subtypes of peripheral blood immune cells in newly diagnosed young type 1 diabetes patients.

Type 1 diabetes (T1D) results from autoimmune destruction of insulin-producing beta cells in pancreatic islets. Various immune cell populations are involved in disease development and natural course. However, to our knowledge, so far there are no comprehensive comparative investigations of all main immune cell populations and their most important subsets at the onset of disease. Therefore, in the current study, we analyzed 51 peripheral blood immune cell populations in 22 young T1D patients and in 25 age-matched controls using a comprehensive polychromatic flow cytometry panel developed for whole blood by the COST Action no. BM0907 ENTIRE (European Network for Translational Immunology Research and Education: From Immunomonitoring to Personalized Immunotherapy) consortium. We found that in T1D patients, frequencies and absolute counts of natural killer (NK) cells, dendritic cells (DC) and T cells, as well as their respective subsets, were significantly altered compared to controls. Further, we observed that changes in several cell populations (e.g. CD14+ CD16+ non-classical monocytes, plasmablasts) were dependent on the age of the patient. In addition to age-related changes, we also found that alterations in immune cell patterns were associated with parameters such as the presence of ketoacidosis and C-peptide serum levels. Our study provides a foundation for future studies investigating different cell lineages and their role in T1D and illustrates the value of polychromatic flow cytometry for evaluating all main peripheral immune cells and their subsets in whole blood samples.

The associations between the changes in serum inflammatory markers and bone mineral accrual in boys with overweight and obesity during pubertal maturation: a 3-year longitudinal study in Estonian boys.

Adipose tissue produces different inflammatory cytokines which compromise bone mineral accrual during puberty. Vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), interleukin (IL)-8, and interferon-gamma (IFN-γ) are significantly related to bone mineral accrual during pubertal maturation in boys with different BMI values. INTRODUCTION: This longitudinal study aims to identify the inflammatory markers that most strongly associate with pubertal bone mineral density (BMD) increment in boys with overweight and obesity (OWB). METHODS: Twenty-six OWB and 29 normal-weight boys were followed yearly for 3 years to measure changes in 12 serum inflammatory markers, BMD (by DXA), and apparent volumetric BMD. The OWB group was further divided into two subgroups according to their BMI gain during the 3-year period. Data through time points presented as slopes were used to calculate correlation coefficients to explore the possible relationships between variables of interest. In the whole study group, linear mixed effects (LME) models were also used. RESULTS: Increment in serum VEGF concentration was inversely associated with an increase in total body (TB) BMD (r = - 0.82, P = 0.02) and TB bone mineral content (BMC)/height (r = - 0.82, P = 0.02) in those OWB whose BMI gain was higher during pubertal years. In the whole study group, the LME model confirmed the inverse association between VEGF and TB BMC/height (P < 0.05). EGF was inversely associated with LS BMD and LS BMAD (P < 0.05), whereas there was a positive association between IL-8 and TB BMAD and between IFN-γ and LS BMD (P < 0.05). CONCLUSIONS: Lower increment in BMD in OWB with higher BMI gain is associated with increasing serum VEGF concentration during pubertal maturation. VEGF, EGF, IL-8, and IFN-γ are significantly associated with BMD during pubertal maturation in boys with different BMI values.

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.

Increased sclerostin and preadipocyte factor-1 levels in prepubertal rhythmic gymnasts: associations with bone mineral density, body composition, and adipocytokine values.

SUMMARY: Rhythmic gymnastics as high-impact bone loading sport has positive effects on bone mineralization in prepubertal years. Sclerostin and preadipocyte factor-1 (Pref-1) are hormones that inhibit bone formation. The present study demonstrates that these hormones are higher in gymnasts, and gymnasts present higher bone mineral density (BMD) as compared to controls. INTRODUCTION: Rhythmic gymnasts (RG) start their heavy trainings already in prepuberty and despite of low body fat mass (FM) and hypoleptinemia, their BMD is higher than in non-trained normal girls. The specific role of sclerostin and Pref-1, which are the inhibitors of bone formation, in bone development is not well understood. The impact of sclerostin and Pref-1 levels on BMD, body composition, and adipocytokine values was studied in prepubertal RG and untrained controls (UC). METHODS: Sixty-four 9-10-year-old girls were divided into RG (n = 32) and UC (n = 32) groups. Bone mineral and body composition values were measured by dual-energy X-ray absorptiometry and bone age by X-ray. Sclerostin, Pref-1, leptin, and adiponectin levels were measured from fasting blood samples. RESULTS: Sclerostin (RG 19.8 ± 6.3 pmol/l; UC 15.8 ± 5.4 pmol/l) and Pref-1 (RG 1.6 ± 1.0 ng/ml; UC 1.1 ± 0.5 ng/ml) were higher (p < 0.05) in RG compared with UC. Sclerostin was related to adiponectin (r = 0.41; p < 0.05) in UC. No relationship was found between sclerostin and Pref-1 with BMD values in prepubertal RG and age-matched UC groups. CONCLUSIONS: Sclerostin and Pref-1 levels are higher in RG compared to UC girls. Specific physical activity pattern seen in prepubertal RG has a beneficial effect on bone mineralization despite increased levels of hormones that inhibit bone formation.

Differences in B7 and CD28 family gene expression in the peripheral blood between newly diagnosed young-onset and adult-onset type 1 diabetes patients.

Type-1 diabetes (T1D) is a heterogeneous autoimmune disease, and there are pathogenetic differences between young- and adult-onset T1D patients. We hypothesized that the expressions of genes involved in costimulatory immune system pathways in peripheral blood are differently regulated in young- and adult-onset T1D. Study group I consisted of 80 children, adolescents, and young adults (age range 1.4-21.4 y; 31 controls and 49 T1D patients). Study group II consisted of 48 adults (age range 22.0-78.4 y; 30 controls and 18 T1D patients). The mRNA expression levels of CD86, CD28, CD25, CD226, CD40, BTLA, GITR, PDCD1, FoxP3, TGF-ß, ICOS, sCTLA4, flCTLA4, and CD80 were measured in peripheral blood. Genetic polymorphisms (HLA haplotypes; rs231806, rs231775, and rs3087243 in CTLA4; rs763361 in CD226; and rs706778 in CD25) and T1D-associated autoantibodies were analyzed. In group I, there was significantly lower expression of CD226 in T1D patients than in the controls. In group II, there were significantly higher expression levels of CD86 and TGF-ß in T1D patients than in the controls. In the T1D patients in group I, the upregulated CD80 expression correlated with the expression of both CTLA4 splice variants (sCTLA4 and flCTLA4). In contrast, in group II, upregulated CD86 correlated with TGF-ß and CD25. In group I, the inhibitory CD80-CTLA4 pathway was activated, whereas, in group II, the activation CD86-CD28 pathway and TGF-ß production were activated. These results emphasize the differences between young-onset and adult-onset T1D in the regulation of costimulatory pathways. These differences should be considered when developing novel treatments for T1D.

Green areas around homes reduce atopic sensitization in children.

BACKGROUND: Western lifestyle is associated with high prevalence of allergy, asthma and other chronic inflammatory disorders. To explain this association, we tested the 'biodiversity hypothesis', which posits that reduced contact of children with environmental biodiversity, including environmental microbiota in natural habitats, has adverse consequences on the assembly of human commensal microbiota and its contribution to immune tolerance. METHODS: We analysed four study cohorts from Finland and Estonia (n = 1044) comprising children and adolescents aged 0.5-20 years. The prevalence of atopic sensitization was assessed by measuring serum IgE specific to inhalant allergens. We calculated the proportion of five land-use types--forest, agricultural land, built areas, wetlands and water bodies--in the landscape around the homes using the CORINE2006 classification. RESULTS: The cover of forest and agricultural land within 2-5 km from the home was inversely and significantly associated with atopic sensitization. This relationship was observed for children 6 years of age and older. Land-use pattern explained 20% of the variation in the relative abundance of Proteobacteria on the skin of healthy individuals, supporting the hypothesis of a strong environmental effect on the commensal microbiota. CONCLUSIONS: The amount of green environment (forest and agricultural land) around homes was inversely associated with the risk of atopic sensitization in children. The results indicate that early-life exposure to green environments is especially important. The environmental effect may be mediated via the effect of environmental microbiota on the commensal microbiota influencing immunotolerance.

Energy metabolism and thyroid function of mice with deleted wolframin (Wfs1) gene.

There is no data about the energy metabolism of patients with Wolfram syndrome caused by mutations in the wolframin (Wfs1) gene. The aim of this study was to investigate the role of Wfs1 in energy metabolism and thyroid function in Wfs1 deficient mice (Wfs1KO). 16 male (8 Wfs1KO, 8 wild type (wt)) and 16 female (8 Wfs1KO, 8wt) mice aged 11-13 weeks were studied alone in a specific metabolic cage for 48 h. Body weight, food, water and O2 consumption, motor activity, CO2 and heat production of mice were recorded. At the age of 14-20 weeks, plasma levels of thyroxine (T4), TSH and leptin were measured and histology of thyroid tissues examined. Mean CO2 and heat production was not different between the groups. Mean O2 consumption was higher in the Wfs1KO females compared to the Wfs1KO males (3 410.0±127.0 vs. 2 806.0±82.4 ml/kg/h; p<0.05), but not compared to the wt mice. The mean movement activity was not different between the groups except that the Wfs1KO females reared up more often than the wt females (199.8±63.46 vs. 39.26±24.71 cnts/48 h; p<0.05). Both male and female Wfs1KO mice had significantly lower body mass and food intake than wt mice. Male Wfs1KO mice also lost more weight in metabolic cage than wt males (20.43±0.41 vs. 16.07±0.86%; p<0.05) indicating more pronounced response to isolation. Male Wfs1KO mice had significantly lower levels of plasma leptin than wt male mice (3.37±0.40 vs. 5.82±0.71 ng/ml; p<0.01). Thyroid function measured by serum TSH and T4 levels was not different between Wfs1KO and wt groups, but both Wfs1KO and wt male mice had significantly higher mean T4 levels than female mice. The histology of thyroid tissue of Wfs1KO males showed a trend to a smaller mean number of epithelial cells per follicle than the wt male mice.Although Wfs1KO mice were smaller and lost more weight during the experiment, their energy metabolism was not different from wt mice except that the female Wfs1KO mice consumed more O2. As mice in this study were relatively young, longitudinal studies in older mice are necessary to clarify whether Wfs1 has a role in energy metabolism when the disease progresses further.

No association between vitamin D and ß-cell autoimmunity in Finnish and Estonian children.

BACKGROUND: Vitamin D has immunomodulatory properties, such as regulation of FOXP3 expression and regulatory T-cell activity. Our aim was to investigate whether plasma 25-hydroxyvitamin D [25(OH)D] concentrations associate with the development of ß-cell autoimmunity and the transcriptional activity of FOXP3 or vitamin D3 convertase gene (CYP27B1) in CD4+ memory T cells. METHODS: We studied 83 Finnish and 32 Estonian children participating in the DIABIMMUNE and DIPP studies. Twenty-nine Finnish and six Estonian children tested positive for at least one diabetes-associated autoantibody. The plasma concentrations of 25(OH)D and 1,25(OH)2D were analysed with an enzyme immunoassay. Gene expression of FOXP3 and CYP27B1 in the isolated CD4+ memory T cells was studied with reverse transcription quantitative polymerase chain reaction. RESULTS: Vitamin D status did not differ between subjects positive and negative for ß-cell autoantibodies. Finnish children had higher vitamin D status than Estonian children (p < 0.001). FOXP3 expression was higher in Estonian CD4+ memory T-cell samples than in Finnish samples (p < 0.01) even when including in both groups only children with serum 25(OH)D concentrations in the range of 50-80 nmol/L (p < 0.001). CONCLUSIONS: These findings do not support a crucial role of circulating 25(OH)D as a regulator of ß-cell autoimmunity or FOXP3 expression.

Translational neuroendocrinology: control of human growth.

Human growth is driven by both basic cell processes as well as hormones, in particular the growth hormone (GH)-insulin-like growth factor (IGF)-1 axis. Understanding how these mechanisms are coordinated is not only critical to achieving a normal growth rate, but also to recognising potential new causes of disordered growth and how they might be treated. We have demonstrated in healthy children that height is gained by periods of rapid growth interspersed by periods of very slow growth or even stasis. We have also shown that a lower order organism, Caenorhabditis elegans, grows in a similar manner. By contrast, secretion of GH from somatotrophs occurs on a daily basis in discrete pulses over a 24-h period. We have used the measurement of GH in urine as a surrogate marker of GH secretion to show that there are rhythms of GH output with frequencies of several days. We then assessed which attributes of these GH profiles were related to growth and found that disorderliness in the GH profile (as measured by approximate entropy) was related to better growth rate. This feature was then tested in the dwarf rat using different GH regimens to introduce variation into the administration of daily GH injections. Better long bone growth was associated with week-to-week or even random dose variation compared to the same amount of GH delivered as a standard daily dose. Understanding the control of growth has implications in clinical practice for modelling GH treatment regimens based on physiological principles.

Serum interferon gamma concentration is associated with bone mineral density in overweight boys.

UNLABELLED: Childhood obesity has recently been linked to low-grade inflammation. Overweight children have slightly different processes of bone accumulation than normal weight children. The possible links between inflammation and bone accumulation have not previously been assessed in overweight children. AIMS: An exploratory study to assess whether common inflammatory markers are associated with the development of obesity and bone accumulation in childhood. METHODS: Thirteen different inflammatory markers in serum were measured in 38 boys with BMI >85th centile (overweight) and 38 boys with normal BMI (normal weight), aged 10-11 years. Total body (TB) and lumbar spine (LS) bone mineral density (BMD), bone mineral content (BMC) were measured by DXA. TB BMC for height, TB and LS bone mineral apparent density (BMAD) were calculated. RESULTS: Overweight boys had higher mean TB and LS BMD, TB BMC and TB BMC for height, but lower mean TB BMAD (all p < 0.05) than normal weight boys. Serum interferon gamma (IFNγ) concentration was significantly (p < 0.05) correlated with TB BMD (r = 0.36), TB BMC (r = 0.38) and TB BMC for height (r = 0.53) in the broader overweight group (n = 38). In obese boys (BMI > 95 centile, n = 36) IFNγ was correlated with LS BMD (r = 0.38). CONCLUSION: The positive correlation between serum INFγ concentration and BMD suggests that the inflammatory process, already involved in the early stage of obesity, may also affect bone accumulation. Further studies are needed to clarify the role of INFγ as a possible link between adipose tissue and bone health.

Early postnatal growth in children with HLA-conferred susceptibility to type 1 diabetes.

AIMS/HYPOTHESIS: An association between increased length/height and weight gain and risk of type 1 diabetes (T1D) has been reported in children. We set out to investigate the potential contribution of T1D human leukocyte antigen (HLA) risk genotypes to this association in two countries with a contrasting disease incidence. METHODS: In Estonia and Finland, length and weight were monitored up to the age of 24 months in 688 subjects. According to their HLA genotypes, the children were divided into four groups, those with very high, high or moderate risk for T1D, as well as a neutral/control group. Relative length and weight (SDS) were assessed and compared at 3, 6, 12, 18 and 24 months using World Health Organization (WHO) growth curves. RESULTS: The mean relative length at the age of 24 months was lower in the group with the very high risk HLA genotype compared to the controls (p < 0.05). The mean relative weight differed between those two groups at the age of 12, 18 and 24 months (p < 0.05). When Estonian and Finnish cohorts were analyzed separately, the relative length showed similar but non-significant trends in both countries, while in Estonia the changes in weight at some time points still remained significant (p < 0.05). CONCLUSIONS: Children with the highest HLA-conferred risk for T1D gained less weight and length during the first 24 months of life, and this feature was more pronounced in the Estonian children.

Elevated serum IL-6, IL-8, MCP-1, CRP, and IFN-γ levels in 10- to 11-year-old boys with increased BMI.

BACKGROUND/AIMS: Many inflammation parameters are associated with obesity, but few comparable data are found in youth. This study aims to characterize the differences in serum levels of 13 biochemical inflammatory markers between boys with increased BMI and boys with normal BMI, and examine the relationships between inflammation markers, skinfold thicknesses, and body composition. PARTICIPANTS/METHODS: The participants were 38 boys (BMI above 85th percentile) and 38 boys (normal BMI) at the age of 10-11 years. Measurements included BMI, 9 skinfold thicknesses, waist and hip circumferences, and total body and trunk fat mass and percentage as indices of obesity, fasting insulin, glucose, and serum concentrations of IL-2, IL-4, IL-6, IL-8, IL-10, VEGF, IFN-γ, TNF-α, IL-1α, IL-1ß, monocyte chemoattractant protein-1 (MCP-1), epidermal growth factor, and CRP. RESULTS: Overweight boys (OWB) were taller and more frequently in puberty than normal-weight boys (NWB). Skinfold thicknesses and body composition parameters were higher in OWB. They had significantly higher serum IL-6, IL-8, IFN-γ, MCP-1, and CRP values compared to NWB. CONCLUSIONS: Six of 13 measured biochemical markers were significantly increased in OWB, indicating that many low-grade inflammatory processes are already involved in the development of obesity in childhood.

Sex differences in the development of diabetes in mice with deleted wolframin (Wfs1) gene.

Wolfram syndrome, caused by mutations in the wolframin (Wfs1) gene, is characterised by juvenile-onset diabetes mellitus, progressive optic atrophy, diabetes insipidus and deafness. Diabetes tend to start earlier in boys. This study investigated sex differences in longitudinal changes in blood glucose concentration (BGC) in wolframin-deficient mice (Wfs1KO) and compared their plasma proinsulin and insulin levels with those of wild-type (wt) mice. Non-fasting BGC was measured weekly in 42 (21 males) mice from both groups at nine weeks of age. An intraperitoneal glucose tolerance test (IPGTT) was conducted at the 30 (th) week and plasma insulin, c-peptide and proinsulin levels were measured at the 32 (nd) week. At the 32 (nd) week, Wfs1KO males had increased BGC compared to wt males (9.40±0.60 mmol/l vs. 7.91±0.20 mmol/l; p<0.05). The opposite tendency was seen in females. Both male and female Wfs1KO mice had impaired glucose tolerance on IPGTT. Wfs1KO males had significantly lower mean plasma insulin levels than wt males (57.78±1.80 ng/ml vs. 69.42±3.06 ng/ml; p<0.01) and Wfs1KO females (70.30±4.42 ng/ml; p<0.05). Wfs1KO males had a higher proinsulin/insulin ratio than wt males (0.09±0.02 vs. 0.05±0.01; p=0.05) and Wfs1KO females (0.04±0.01; p<0.05). Plasma c-peptide levels in males were lower in Wfs1KO males (mean 55.3±14.0 pg/ml vs. 112.7±21.9 pg/ml; p<0.05). Male Wfs1KO mice had a greater risk of developing diabetes than female Wfs1KO mice. Low plasma insulin concentration with an increased proinsulin/insulin ratio in Wfs1KO males indicates possible disturbances in converting proinsulin to insulin which in long-term may lead to insulin deficiency. Further investigation is needed to clarify the mechanism for the sex differences in the development of diabetes in Wolfram syndrome.

Effect of pubertal development and physical activity on plasma ghrelin concentration in boys.

The aim of the present study was to assess the influence of regular physical activity on plasma ghrelin concentration in pre-pubertal and pubertal boys. In addition, the impact of ghrelin concentration on bone mineral density (BMD) was examined. In total, 56 healthy schoolboys aged between 10 and 16 yr were divided into the swimming (no.=28) and the control (no.=28) groups. The subjects were matched by age and body mass index (BMI), generating 9 matched pairs in pubertal group I (Tanner stage 1), 11 pairs in group II (Tanner stages 2 and 3), and 8 pairs in group III (Tanner stages 4 and 5). Swimmers in pubertal groups II and III had significantly (both p<0.05) higher mean ghrelin levels than the controls (group II: 1126.8+/-406.0 vs 868.3+/-411.2 pg/ml; group III: 1105.5+/-337.5 vs 850.8+/-306.0 pg/ml, respectively), whereas no difference was seen in the pubertal group I (1230.8+/-386.0 vs 1272.7+/-424.4 pg/ml). Ghrelin was the most important hormonal determinant for total BMD and lumbar apparent volumetric BMD (BMAD) (R2=27.2% and R2=19.8%, respectively) in swimmers, whereas in control boys, plasma IGF-I was the most important hormonal predictor accounting for 41.8% of the variability of total BMD and 20.4% of the variability of lumbar BMAD. In conclusion, ghrelin concentration decreased during puberty in physically inactive boys, while in regularly physically active boys it remained relatively unchanged. Ghrelin appears to be an important hormonal predictor for BMD in physically active boys, while BMD is mostly determined by IGF-I in physically inactive boys.

Wfs1 gene deletion causes growth retardation in mice and interferes with the growth hormone pathway.

The aim of present study was to describe changes in gene expression in the temporal lobe of mice induced by deletion of the Wfs1 gene. Temporal lobes samples were analyzed using Affymetrix Mouse Genome 420 2 GeneChips and expression profiles were functionally annotated with GSEA and Ingenuity Pathway Analysis. We found that Wfs1 mutant mice are significantly smaller (20.9 +/- 1.6 g) than their wild-type counterparts (31.0 +/- 0.6 g, P < 0.0001). This difference existed in 129S6 and C57B6 backgrounds. Interestingly, microarray analysis identified upregulation of growth hormone (GH) transcripts and functional analysis revealed activation of GH pathways. In line with microarray data, the level of IGF-1 in the plasma of Wfs1 mutant mice was significantly increased (P < 0.05). Thus, Wfs1 deletion induces growth retardation, whereas the GH pathway is activated. To test the interaction between the Wfs1 deletion and genomic background, mutant mice were backcrossed to two different genetic backgrounds. In line with previous studies, an interaction between a gene knockout and genetic background was found in gene expression profiles in the congenic region. However, genetic background did not alter the effect of the Wfs1 mutation on either body weight or GH pathway activation. Further studies are needed to describe biochemical and molecular changes of the growth hormone axis as well as in other hormones to clarify their role in growth retardation in the Wfs1 mutant mice.

The reference limits and cut-off value for serum soluble transferrin receptors for diagnosing iron deficiency in infants.

Serum soluble transferrin receptors (sTfR) concentration is a useful test in the diagnosis of childhood iron deficiency (ID). The aims of this study were to establish reference limits and to evaluate the diagnostic characteristics of sTfR in the diagnosis of ID in infants aged 9-12 months. In addition to mean erythrocyte cell volume, haemoglobin and ferritin measurements, sTfR concentration was measured in 179 healthy children in Estonia using the IDeA and Tina-quant methods. Using the ID criteria of ferritin <10 microg/l, subjects were divided into healthy (n = 146) and ID (n = 33) groups. The reference limits (5th and 95th percentile) were calculated in the study group. We used receiver operating characteristic curves to find out the cut-off values for the best diagnostic characteristics. The reference limits for sTfR were 1.5-2.7 mg/l in the IDeA method and 4.1-7.8 mg/l in the Tina-quant) method. The methods had poor agreement, the mean ratio with 95% limits of agreement was 2.9 (2.4-3.6). The best cut-off value in order to identify ID by hypoferritinaemia in this population is an sTfR level > 2.4 mg/l in the IDeA (sensitivity 84%, specificity 94%) and an sTfR level > 7.4 mg/l in the Tina-quant (sensitivity 80%, specificity 92%). We conclude that sTfR concentration is an efficient tool in the diagnosis of ID, but that every method needs its own cut-off value.

Protein tyrosine phosphatase non-receptor type 22 gene variants at position 1858 are associated with type 1 and type 2 diabetes in Estonian population.

Protein tyrosine phosphatase non-receptor type 22 (PTPN22) is considered an important regulator of T-cell activation. Polymorphisms within the PTPN22 gene have been suggested to confer susceptibility to autoimmune endocrine disorders. To evaluate the impact of a functional variation in the PTPN22 gene in type 1 (T1D) and type 2 diabetes (T2D), the PTPN22 C1858T single nucleotide polymorphism (SNP) was studied in the population of Estonian origin, including 170 T1D patients, 244 T2D patients and 230 controls. Using two methods for PTPN22 C1858T detection in parallel, we found that not only T1D but also T2D is associated with the PTPN22 1858T allele. The role of PTPN22 gene in the pathogenesis of T2D is yet unclear and needs further investigation.

Impact of acute exercise on bone turnover and growth hormone/insulin-like growth factor axis in boys.

AIM: The aim of this study was to investigate the response of N-terminal propeptide of type I procollagen, crosslinked telopeptide of type I collagen and the growth hormone/insulin-like growth factor-I axis to acute aerobic exercise in boys at different pubertal stages METHODS: The subjects were 60 healthy boys (group I - Tanner stage 1, N=20; group II - Tanner stages 2 and 3, N=20; group III - Tanner stages 4 and 5, N=20) who exercised 30 minutes at constant load on cycle ergometer at the level of ~95% of their individual ventilatory threshold. Venous blood samples were obtained before, immediately after and after 30 minutes of recovery for the measurement of serum testosterone, growth hormone (GH), insulin-like-growth factor-I, insulin-like-growth factor binding protein-3, N-terminal propeptide of type I procollagen (PINP) and crosslinked telopeptide of type I collagen. RESULTS: Acute exercise did not affect significantly serum testosterone, insulin-like-growth factor-I, insulin-like-growth factor binding protein-3 or bone turnover markers concentrations in any of study groups. The rise in growth hormone concentration during exercise was highest in group III (62.3+/-41.7 mU/L vs 15.5+/-11.4 in group I and 41.8+/-20.0 in group II). The increment in serum growth hormone level during exercise was positively correlated (r=0.64; P<0.001) to basal serum testosterone concentration. CONCLUSIONS: It can be concluded that growth hormone response to exercise was directly dependent on serum testosterone concentration. Acute exercise did not affect serum testosterone, insulin-like-growth factor-I, insulin-like-growth factor binding protein-3 or bone markers levels.

Preliminary evidence of a sensitive period for olfactory learning by human newborns.

AIM: To test the hypothesis that a brief window of time immediately after delivery may be a particularly sensitive period for olfactory learning by human neonates. METHODS: Fifty-five vaginally delivered newborns were exposed to an odorant for 30 min beginning 4-37 min after birth (Early exposure) or 12-h post-partum (Late exposure). Several days later, newborns' head orientation responses to the exposure odour versus an unfamiliar odour or an odourless control stimulus were tested. RESULTS: Infants in the Early exposure group spent significantly more time oriented towards the familiar scent rather than a novel odour (Z = 2.869; n = 28; p < 0.01), or an odourless stimulus (Z = 2.550; n = 28; p < 0.01). Infants in the Late exposure condition did not respond differentially to the exposure odour versus a novel odour (Z = 1.105; n = 27, p = 0.27), and spent more time oriented towards an odourless stimulus than to the exposure odour (Z = 2.042; n = 27, p < 0.05). CONCLUSION: Infants in the Early exposure group, but not in the Late exposure group, became familiar with the exposure odour and retained a memory trace of it during the test trials.

Insulin VNTR I/III genotype is associated with autoantibodies against glutamic acid decarboxylase in newly diagnosed type 1 diabetes.

BACKGROUND: In type 1 diabetes (T1D), the influence of age at diagnosis and of the IDDM1 and IDDM2 genetic susceptibility loci on the profile of beta-cell autoantibodies has been demonstrated. We studied these associations in a group of 92 patients (children, adolescents and adults, aged 2-62 years) with newly diagnosed T1D. METHODS: The prevalence of the HLA-DQB1*02 and *0302 alleles and of the classes of variable number of tandem repeats (VNTR) of the insulin gene (INS), and of beta-cell autoantibodies (GADA, IA-2A, ICA and IAA) was determined. Statistical analysis was performed using linear and logistic regression models. RESULTS: The presence of IAA, IA-2A and ICA, but not of GADA, was negatively associated with age at diagnosis. Younger patients were more likely to have multiple autoantibodies. There was a tendency of a higher prevalence of IAA in patients with the HLA-DQB1*02/0302 genotype or with the DQB1*0302 allele compared to patients lacking these markers. As a novel observation, the INS VNTR I/III genotype was significantly associated with the presence of GADA (OR = 4.79; p = 0.018). CONCLUSION: The association between the INS VNTR I/III genotype and GADA may suggest that in patients with T1D lacking the INS VNTR I/I genotype, the effect of other susceptibility factors prevails, which promotes the development of autoimmunity to beta-cell antigens other than insulin.