Expression of the filaggrin gene in umbilical cord blood predicts eczema risk in infancy: A birth cohort study

Newborn DNA methylation and asthma acquisition across adolescence and early adulthood

BACKGROUND

Little is known about the association of newborn DNA methylation (DNAm) with asthma acquisition across adolescence and early adult life.

OBJECTIVE

We aim to identify epigenetic biomarkers in newborns for asthma acquisition during adolescence or young adulthood.

METHODS

The Isle of Wight Birth Cohort (IOWBC) (n = 1456) data at ages 10, 18 and 26 years were assessed. To screen cytosine-phosphate-guanine site (CpGs) potentially associated with asthma acquisition, at the genome scale, we examined differentially methylated regions (DMR) using dmrff R package and individual CpG sites using linear regression on such associations. For CpGs that passed screening, we examined their enrichment in biological pathways using their mapping genes and tested their associations with asthma acquisitions using logistic regressions. Findings in IOWBC were tested in an independent cohort, the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort.

RESULTS

In total, 2636 unique CpGs passed screening, based on which we identified one biological pathway linked to asthma acquisition during adolescence in females (FDR adjusted p-value = .003 in IOWBC). Via logistic regressions, for females, four CpGs were shown to be associated with asthma acquisition during adolescence, and another four CpGs with asthma acquisition in young adulthood (FDR adjusted p-value < .05 in IOWBC) and these eight CpGs were replicated in ALSPAC (all p-values < .05). DNAm at all the identified CpGs was shown to be temporally consistent, and at six of the CpGs was associated with expressions of adjacent or mapping genes in females (all p-values < .05). For males, 622 CpGs were identified in IOWBC (FDR = 0.01), but these were not tested in ALSPAC due to small sample sizes.

CONCLUSION AND CLINICAL RELEVANCE

Eight CpGs on LHX5, IL22RA2, SOX11, CBX4, ACPT, CFAP46, MUC4, and ATP1B2 genes have the potential to serve as candidate epigenetic biomarkers in newborns for asthma acquisition in females during adolescence or young adulthood.

Filaggrin mutations in relation to skin barrier and atopic dermatitis in early infancy

BACKGROUND

Loss-of-function mutations in the skin barrier gene filaggrin (FLG) increase the risk of atopic dermatitis (AD), but their role in skin barrier function, dry skin and eczema in infancy is unclear.

OBJECTIVES

To determine the role of FLG mutations for impaired skin barrier function, dry skin, eczema and AD at three months of age and through infancy.

METHODS

FLG mutations were analyzed in 1836 infants in the Scandinavian population-based PreventADALL study. Transepidermal water loss (TEWL), dry skin, eczema and AD were assessed at three, six and 12 months of age.

RESULTS

Filaggrin mutations were observed in 166 (9%) infants. At three months, carrying FLG mutations was not associated with impaired skin barrier function (TEWL > 11.3 g/m² /h) or dry skin, but with eczema (OR(95%CI): 2.76 (1.81, 4.23), p < 0.001). At six months, mutation carriers had significantly higher TEWL than non-mutation carriers (mean (95%CI) 9.68 (8.69, 10.68) vs. 8.24 (7.97, 8.15), p < 0.01) and at three and six months an increased risk of dry skin on truncus (OR: 1.87 (1.25, 2.80), p = 0.002; 2.44 (1.51, 3.95), p < 0.001) or extensor limb surfaces (1.52 (1.04, 2.22), p = 0.028; 1.74 (1.17, 2.57), p = 0.005). FLG mutations were associated with eczema and AD in infancy.

CONCLUSION

Filaggrin mutations were not associated with impaired skin barrier function or dry skin in general at three months of age, but increased the risk for eczema, as well as for dry skin on truncus and extensors at three and six months.

Incidence of Eczema in Early Infancy and the Prenatal Risk Factors - Guangzhou, Guangdong, China, 2018-2019

What is already known on this topic?

Eczema is a common allergic disease in children, which seriously affects the quality of life of children and their families.

What is added by this report?

The results showed that the incidence of very-early-onset eczema was 12.4%. Primiparity was associated with a higher risk of eczema [risk ratio (95% confidence interval): 1.23 (1.06–1.42)].

What are the implications for public health practice?

Very-early-onset eczema is common. Given its adverse impact on children’s health and life quality, this previously neglected public health issue needs to be prioritized. In addition, maternal parity could serve as an indicator in risk assessment and prediction for infant eczema.

Genetics and Epigenetics of Atopic Dermatitis: An Updated Systematic Review

BACKGROUND

Atopic dermatitis is a common inflammatory skin disorder that affects up to 15-20% of the population and is characterized by recurrent eczematous lesions with intense itching. As a heterogeneous disease, multiple factors have been suggested to explain the nature of atopic dermatitis (AD), and its high prevalence makes it necessary to periodically compile and update the new information available. In this systematic review, the focus is set at the genetic and epigenetic studies carried out in the last years.

METHODS

A systematic literature review was conducted in three scientific publication databases (PubMed, Cochrane Library, and Scopus). The search was restricted to publications indexed from July 2016 to December 2019, and keywords related to atopic dermatitis genetics and epigenetics were used.

RESULTS

A total of 73 original papers met the inclusion criteria established, including 9 epigenetic studies. A total of 62 genes and 5 intergenic regions were described as associated with AD.

CONCLUSION

Filaggrin (FLG) polymorphisms are confirmed as key genetic determinants for AD development, but also epigenetic regulation and other genes with functions mainly related to the immune system and extracellular matrix, reinforcing the notion of skin homeostasis breakage in AD.

Developments in the field of allergy in 2017 through the eyes of Clinical and Experimental Allergy

In this article, we described the development in the field of allergy as described by Clinical and Experimental Allergy in 2017. Experimental models of allergic disease, basic mechanisms, clinical mechanisms, allergens, asthma and rhinitis and clinical allergy are all covered.

It's not just the food you eat: Environmental factors in the development of food allergies

The dramatic rise in the prevalence of food allergy and food allergy-associated anaphylaxis in the past few decades has fueled investigative interest into understanding this puzzling trend. Here, we review the question as to whether important external environmental determinants beyond dietary habits and exposure to food allergens are involved. This review will summarize our current understanding of these environment determinants, derived from the latest experimental and epidemiological research. Specifically, we will review the role of exposures that affect skin barrier function, development of a diverse microbiome, and food processing. Additional exposures of concern are insufficient sunlight, endocrine disrupting chemicals and pesticides, and use of specific pharmaceutical agents that may drive or modify the risk for food allergy. Despite limitations in the quantity and quality of research to date, many new epidemiological associations and experimental data in support of this paradigm have emerged.

New insights into the phenotypes of atopic dermatitis linked with allergies and asthma in children: An overview

Atopic dermatitis (AD) is a complex disease with multiple causes and complex mechanistic pathways according to age of onset, severity of the illness, ethnic modifiers, response to therapy and triggers. A group of difficult-to-manage patients characterized by early-onset AD and severe lifelong disease associated with allergic asthma and/or food allergy (FA) has been identified. In this study, we focus on these severe phenotypes, analysing their links with other atopic comorbidities, and taking into account the results from recent cohort studies and meta-analyses. The main hypothesis that is currently proposed to explain the onset of allergic diseases is an epithelial barrier defect. Thus, the atopic march could correspond to an epithelial dysfunction, self-sustained by a secondary allergenic sensitization, explaining the transition from AD to allergic asthma. Furthermore, AD severity seems to be a risk factor for associated FA. Results from population-based, birth and patient cohorts show that early-onset and severe AD, male gender, parental history of asthma, and early and multiple sensitizations are risk factors leading to the atopic march and the development of asthma. The importance of environmental factors should be recognized in these high-risk children and prevention programs adapted accordingly. Effective targeted therapies to restore both barrier function and to control inflammation are necessary; early emollient therapy is an important approach to prevent AD in high-risk children. Clinicians should also keep in mind the specific risk of atopic comorbidities in case of filaggrin loss-of-function mutations and the rare phenotypes of orphan syndromes due to heritable mutations in skin barrier components.