Prenatal and Early Postnatal Exposure to Total Mercury and Methylmercury from Low Maternal Fish Consumption

The aim of this study was to investigate the influence of low fish consumption on prenatal and early postnatal exposure to mercury species. The samples of umbilical cord blood and maternal milk as well as interviewer-administered questionnaires were collected from 142 Slovak mother-child pairs. The mean total mercury (THg) concentrations in cord blood and milk were 0.949 μg/L and 0.376 μg/kg, respectively. The mean methylmercury (MeHg) concentration in cord blood was 0.504 μg/L. Fish eaters had significantly higher cord blood MeHg concentrations than non-fish eaters (p = 0.030); no difference was found in milk or cord blood THg concentrations. The bivariate analysis showed a positive correlation between cord blood MeHg and consumption of sea fish and shellfish (r_s = 0.320, p < 0.001); after adjustment for the potential confounders, the association was weakened (β = 0.173, p = 0.059). Nevertheless, the decision tree method showed sea fish and shellfish consumption to be the best predictor of cord blood MeHg. Furthermore, a negative association was found between THg concentrations in maternal milk and freshwater fish consumption (β = - 0.193, p = 0.017), which might indicate a beneficial effect of freshwater fish consumption. The results suggest there is a need for future research to investigate the benefits versus the adverse effects of low maternal fish consumption on child development.

Dynamics of allergy development during the first 5 years of life

Allergic diseases have increased in developed countries during the past decades. A cohort of Slovak children was followed from birth to track allergic symptoms dynamics in early childhood. Information on allergic symptoms (atopic dermatitis = AD, rhino conjunctivitis = RC, wheezing = Wh, urticaria = Ur) and food allergies among children was based on clinical evaluation of children by allergists at three developmental stages (infant, toddler, preschool). Out of 320 cases of allergies, 64 infants, 145 toddlers, and 195 preschool children suffered from AD, RC, Wh, Ur, or their combinations (i.e., significant increase with age, p < 0.001). AD first appeared in infants, Wh and/or RC rose mainly in toddlers, and Ur among preschool children. AD in infants or toddlers disappeared in the subsequent developmental stage in approximately one third of all cases. Single AD persistence without remission or extension was not common and accounted only for 6.9% of AD infants' allergic manifestations. In addition to single-symptom allergic diseases, this study also identified several combinations of atopic symptoms.Conclusions: The proportion of multi-symptom allergies increased while single-symptom forms decreased. The observed temporal trends of allergic symptoms correspond to the atopic march. What is Known: • The observed temporal trends of allergic symptoms correspond to the atopic march. What is New: • Allergic diseases in children were first manifested as single forms, with atopic dermatitis (AD) commonly functioning as the "entry point" to allergies. • The overall proportion of single-symptom allergic disorders decreased over time while the proportion of multi-symptom allergies increased.

Impact of interleukin 13 (IL13) genetic polymorphism Arg130Gln on total serum immunoglobulin (IgE) levels and interferon (IFN)-γ gene expression

This cross-sectional study was designed to investigate the extent of genetic susceptibility by targeting variants in interleukin (IL)-4/IL-13 signalling pathways leading to atopic disease in early childhood. We evaluated involvement of five single nucleotide polymorphisms IL4 C-590T, IL13 C-1055T, IL13 Arg130Gln, IL4RA Ile50Val and IL4RA Gln576Arg, in the control of serum total and antigen-specific immunoglobulin (Ig)E levels. Furthermore, we analysed their association with changes in gene expression of five cytokines having key roles in inflammatory and anti-inflammatory immune response [IL-4, IL-13, interferon (IFN)-γ, IL-8 and IL-10]. Total and antigen-specific IgE levels in serum and gene expression of selected cytokines in peripheral blood were measured in 386 children aged 1-8 years. TaqMan allelic discrimination, amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) and restriction fragment length polymorphisms (RFLP) methods validated by sequencing were used for genotyping. All genotypes for children with total and antigen-specific IgE levels in the normal range were in Hardy-Weinberg equilibrium. Gene expression analyses were carried out using TaqMan gene expression assays. We found elevated total IgE levels in carriers of IL13 Arg130Gln variant allele [odds ratio (OR) = 1·84; 95% confidence interval (CI) = 1·16-2·93]. This effect was more apparent for boys (OR = 2·31; 95% CI = 1·25-4·28). However, no significant association was observed for the other four variants examined. We found up-regulation of IFN-γ in children with elevated serum total IgE levels carrying the Arg130 allele (P = 0·005). No differences were found for IL4, IL8 or IL10, while IL13 gene expression was under the detection limit. IL13 Arg130Gln genotypes can play a role in genetic susceptibility to allergy via regulation of serum total IgE levels and affecting IFN-γ gene expression.