From preschool wheezing to asthma: Environmental determinants

Abstract

Wheezing is common among preschool children, representing a group of highly heterogeneous conditions with varying natural history. Several phenotypes of wheezing have been proposed to facilitate the identification of young children who are at risk of subsequent development of asthma. Epidemiological and immunological studies across different populations have revealed the key role of environmental factors in influencing the progression from preschool wheezing to childhood asthma. Significant risk factors include severe respiratory infections, allergic sensitization, and exposure to tobacco smoke. In contrast, a farming/rural environment has been linked to asthma protection in both human and animal studies. Early and intense exposures to microorganisms and microbial metabolites have been demonstrated to alter host immune responses to allergens and viruses, thereby driving the trajectory away from wheezing illness and asthma. Ongoing clinical trials of candidate microbes and microbial products have shown promise in shaping the immune function to reduce episodes of viral‐induced wheezing. Moreover, restoring immune training may be especially important for young children who had reduced microbial exposure due to pandemic restrictions. A comprehensive understanding of the role of modifiable environmental factors will pave the way for developing targeted prevention strategies for preschool wheezing and asthma.

Prevalence of Wheezing and Its Association with Environmental Tobacco Smoke Exposure among Rural and Urban Preschool Children in Mpumalanga Province, South Africa

“…The present study found that children residing in the Mpumalanga Highveld region were predominantly impacted by Wheeze Ever, a common symptom of asthma, and also had a history of Asthma Ever, particularly if they attended an urban preschool. The results of our study align with the majority of the existing literature, which consistently demonstrates that residing in rural areas or on farms, being exposed to livestock, and the hygiene hypothesis confer protective advantages against the development of asthma and or symptoms in childhood compared to children residing in urban areas [11,20]. Additionally, our research findings provide support for the notion that children residing in urban areas are more prone to increased exposure and heightened sensitivity to several risk factors associated with asthma and or symptoms [21].…”

Preventing progression of preschool wheezing to asthma: Opportunities for intervention

“…The risk factors, both genetic and environmental, influencing the progression of preschool wheezing to asthma have been highlighted in previous articles in this series. [1][2][3][4][5] Influences include underlying susceptibility, antenatal, perinatal and postnatal factors. Novel, data-driven methodological approaches that might help to consolidate the data available and aid our understanding of disease progression have also been discussed.…”

Comparative characterization of interleukin genotypes and risks of bronchial asthma phenotypes in children

“…Генетические факторы играют значительную роль в риске развития бронхиальной астмы, при этом полногеномные ассоциативные исследования показали, что выявленные генетические варианты объясняют только примерно 9% наследственности астмы, что может быть объяснено повышенной пенетрантностью генотипов предрасположенности к астме, факторами окружающей среды, которые проявляют свое влияние через взаимодействие генов и окружающей среды [7,8,9]. Эти данные перенаправили траекторию исследований основных дескрипторов заболеваний от патомеханистического подхода по симптомам и дисфункции органов к распознаванию патогенетических иммунологических, метаболических путей и поиску валидных биомаркеров [1,10,11,12].…”