Harmonizing analytical chemistry and clinical epidemiology for human biomonitoring studies. A case-study of plastic product chemicals in urine.

There is an interdisciplinary interface between analytical chemistry and epidemiology studies with respect to the design, execution, and analysis of environmental epidemiology cohorts and studies. Extracting meaningful results linking chemical exposure to human health outcomes begins at study design and spans the entire workflow. Here we discuss analytical experimental design from an exposure science perspective, and propose a reporting checklist for the design of human biomonitoring studies. We explain key analytical chemistry concepts of blanks and limits of reporting and present a case series of plastic product chemical exposure in prenatal urine specimens from the Barwon Infant Study

Naïve regulatory T cells in infancy: Associations with perinatal factors and development of food allergy

Background In previous studies, deficits in regulatory T‐cell (Treg) number and function at birth have been linked with subsequent allergic disease. However, longitudinal studies that account for relevant perinatal factors are required. The aim of this study was to investigate the relationship between perinatal factors, naïve Treg (nTreg) over the first postnatal year and development of food allergy. Methods In a birth cohort (n = 1074), the proportion of nTreg in the CD4+ T‐cell compartment was measured by flow cytometry at birth (n = 463), 6 (n = 600) and 12 (n = 675) months. IgE‐mediated food allergy was determined by food challenge at 1 year. Associations between perinatal factors (gestation, labour, sex, birth size), nTreg at each time point and food allergy at 1 year were examined by linear regression. Results A higher proportion of nTreg at birth, larger birth size and male sex was each associated with higher nTreg in infancy. Exposure to labour, as compared to delivery by prelabour Caesarean section, was associated with a transient decrease nTreg. Infants that developed food allergy had decreased nTreg at birth, and the labour‐associated decrease in nTreg at birth was more evident among infants with subsequent food allergy. Mode of birth was not associated with risk of food allergy, and there was no evidence that nTreg at either 6 or 12 months were related to food allergy. Conclusion The proportion of nTreg at birth is a major determinant of the proportion present throughout infancy, highlighting the importance of prenatal immune development. Exposure to the inflammatory stimulus of labour appears to reveal differences in immune function among infants at risk of food allergy.</p

Increased maternal mental health burden in a representative longitudinal community cohort coinciding with COVID-19 lockdown

Measures to control the COVID-19 pandemic have disrupted social networks and employment security worldwide. Longitudinal data in representative samples are required to understand the corresponding mental health impacts. We aimed to estimate the prevalence of depressive symptoms in Australian women raising young families during the first Victorian lockdown and to identify risk factors. Participants comprise 347 mothers of children aged 7 (mean age: 32·11 years [4·27]), from the Barwon Infant Study (BIS). Mothers had previously completed Edinburgh Postnatal Depression Scale (EPDS) at child ages zero, two, four. Following the lock down, mothers again completed EPDS along with questions regarding current household and employment demographics. Depressive symptoms were substantially more prevalent in the lockdown sample than at any prior assessment (EPDS10+; 30·6%); and were particularly high in women with previous poor mental health. Anticipated and actual job loss were twice as common relative to previous assessment (5% to 13%, p = 0 006) and (4% to 10%, p = 0 001) and were associated with depressive symptoms. While further studies are required to confirm causal associations, these findings highlight the need to support mental health during the COVID-19 pandemic, particularly in the context of employment insecurity and previous mental illness. KEY POINTS What is already known about this topic: Emerging reports from convenience samples demonstrate elevated depressive symptoms during the COVID-19 pandemic. Maternal mental health is important for child mental health. Representative, longitudinal data are needed to further improve targeting of policy and health service delivery to prevent a post-COVID-19 mental health crisis. What this topic adds: This early report from a population-derived cohort demonstrates high rates of depression symptomatology in mothers of school aged children following the first COVID-19 lockdown. A past history of depression and current threats to employment are identified as key risk factors for adverse mental health. Our findings are consistent with concerns regarding an increase in mental health burden in the wake of the COVID-19 pandemic but further studies are required to assess causality. Interventions and broader community resources to support the mental health of women of school aged children are required, and should target those with a history of depression and current threats to employment

Folate levels in pregnancy and offspring food allergy and eczema

BACKGROUND:High folate status in pregnancy has been implicated in the increased prevalence of allergic disease, but there are no published data relating directly measured folate status in pregnancy to challenge-proven food allergy among offspring. The study aim was to examine the association between red blood cell (RBC) folate status in trimester three of pregnancy and allergic disease among offspring. METHODS:Red blood cell folate levels were measured at 28-32 weeks' gestation in a prospective birth cohort (n = 1074). Food allergy outcomes were assessed in 1-year-old infants by skin prick testing and subsequent food challenge. Eczema was assessed by questionnaire and clinical review. High trimester three RBC folate was defined as greater than (>) 1360 nmol/L. Binomial regression was used to examine associations between trimester three RBC folate and allergic outcomes, adjusting for potential confounders. RESULTS:Red blood cell folate levels were measured in 88% (894/1064) of pregnant women. The mean concentration was 1695.6 nmol/L (standard deviation 415.4) with 82% (731/894) >1360 nmol/L. There was no evidence of either linear or non-linear relationships between trimester three RBC folate and allergic outcomes, nor evidence of associations between high RBC folate and food allergy (adjusted risk ratio (aRR) 2.89, 95% CI 0.90-9.35), food sensitization (aRR 1.72, 95% CI 0.85-3.49), or eczema (aRR 0.97, 95% CI 0.67-1.38). CONCLUSION:The majority of pregnant women in this study had high RBC folate levels. There was no evidence of associations between trimester three RBC folate and food allergy, food sensitization, or eczema among the offspring, although larger studies are required

Naïve regulatory T cells in infancy: Associations with perinatal factors and development of food allergy

Background: In previous studies, deficits in regulatory T-cell (Treg) number and function at birth have been linked with subsequent allergic disease. However, longitudinal studies that account for relevant perinatal factors are required. The aim of this study was to investigate the relationship between perinatal factors, naïve Treg (nTreg) over the first postnatal year and development of food allergy. Methods: In a birth cohort (n\ua0=\ua01074), the proportion of nTreg in the CD4T-cell compartment was measured by flow cytometry at birth (n\ua0=\ua0463), 6 (n\ua0=\ua0600) and 12 (n\ua0=\ua0675)\ua0months. IgE-mediated food allergy was determined by food challenge at 1\ua0year. Associations between perinatal factors (gestation, labour, sex, birth size), nTreg at each time point and food allergy at 1\ua0year were examined by linear regression. Results: A higher proportion of nTreg at birth, larger birth size and male sex was each associated with higher nTreg in infancy. Exposure to labour, as compared to delivery by prelabour Caesarean section, was associated with a transient decrease nTreg. Infants that developed food allergy had decreased nTreg at birth, and the labour-associated decrease in nTreg at birth was more evident among infants with subsequent food allergy. Mode of birth was not associated with risk of food allergy, and there was no evidence that nTreg at either 6 or 12\ua0months were related to food allergy. Conclusion: The proportion of nTreg at birth is a major determinant of the proportion present throughout infancy, highlighting the importance of prenatal immune development. Exposure to the inflammatory stimulus of labour appears to reveal differences in immune function among infants at risk of food allergy

Maternal carriage of Prevotella during pregnancy associates with protection against food allergy in the offspring

In mice, the maternal microbiome influences fetal immune development and postnatal allergic outcomes. Westernized populations have high rates of allergic disease and low rates of gastrointestinal carriage of Prevotella, a commensal bacterial genus that produces short chain fatty acids and endotoxins, each of which may promote the development of fetal immune tolerance. In this study, we use a prebirth cohort (n = 1064 mothers) to conduct a nested case-cohort study comparing 58 mothers of babies with clinically proven food IgE mediated food allergy with 258 randomly selected mothers. Analysis of the V4 region of the 16S rRNA gene in fecal samples shows maternal carriage of Prevotella copri during pregnancy strongly predicts the absence of food allergy in the offspring. This association was confirmed using targeted qPCR and was independent of infant carriage of P. copri. Larger household size, which is a well-established protective factor for allergic disease, strongly predicts maternal carriage of P. copri

Maternal carriage of Prevotella during pregnancy associates with protection against food allergy in the offspring

In mice, the maternal microbiome influences fetal immune development and postnatal allergic outcomes. Westernized populations have high rates of allergic disease and low rates of gastrointestinal carriage of Prevotella, a commensal bacterial genus that produces short chain fatty acids and endotoxins, each of which may promote the development of fetal immune tolerance. In this study, we use a prebirth cohort (n = 1064 mothers) to conduct a nested case-cohort study comparing 58 mothers of babies with clinically proven food IgE mediated food allergy with 258 randomly selected mothers. Analysis of the V4 region of the 16S rRNA gene in fecal samples shows maternal carriage of Prevotella copri during pregnancy strongly predicts the absence of food allergy in the offspring. This association was confirmed using targeted qPCR and was independent of infant carriage of P. copri. Larger household size, which is a well-established protective factor for allergic disease, strongly predicts maternal carriage of P. copri