T cells in severe childhood asthma

Abstract

Summary Severe asthma in children is a debilitating condition that accounts for a disproportionately large health and economic burden of asthma. Reasons for the lack of a response to standard anti‐inflammatory therapies remain enigmatic. Work in the last decade has shed new light on the heterogeneous nature of asthma, and the varied immunopathologies of severe disease, which are leading to new treatment approaches for the individual patient. However, most studies to date that explored the immune landscape of the inflamed lower airways have focused on adults. T cells are pivotal to the inception and persistence of inflammatory processes in the diseased lungs, despite a contemporary shift in focus to immune events at the epithelial barrier. This article outlines current knowledge on the types of T cells and related cell types that are implicated in severe asthma. The potential for environmental exposures and other inflammatory cues to condition the immune environment of the lung in early life to favour pathogenic T cells and steroid resistance is discussed. The contributions of T cells and their cytokines to inflammatory processes and treatment resistance are also considered, with an emphasis on new observations in children that argue against conventional type 1 and type 2 T cell paradigms. Finally, the ability for new technologies to revolutionize our understanding of T cells in severe childhood asthma, and to guide future treatment strategies that could mitigate this disease, is highlighted.

Prevalence of Anemia in Pediatric Patients According to Asthma Control: Propensity Score Analysis

“…IFNγ + T cells was found and inflammatory cytokines such as IL-1 and IL-6 was highly expressed in the lower airways of children with severe asthma. 43 , 44 It has been shown that high level of serum IL-17 and IL-17 + T cells were associated with severe asthma in children. 45 , 46 In addition, Caffarelli’s study demonstrated that pediatric obese patients had a high prevalence of asthma, high hepcidin levels, and low iron levels.…”

A Comprehensive Analysis of Immune Constituents in Blood and Bronchoalveolar Lavage Allows Identification of an Immune Signature of Severe Asthma in Children

“…Although very instructive, such approaches cannot account for the complexity of inflammation in SA. A better understanding of airway and blood inflammation requires expanding beyond the classical paradigms and considering a global approach rather than a targeted one ( 10 , 18 ). Continuing from our previous work ( 17 ), we aimed to identify sets of immune constituents that can distinguish children with SA from age-matched control children using comprehensive, non-targeted, high-dimensional analysis of data on a large set of cytokines and immune cells in blood and BAL.…”

Developments in the mechanisms of allergy in 2018 through the eyes of Clinical and Experimental Allergy, Part I

“…5 Shrestha and colleagues looked at the impact of different pollen types according to daily ambient concentrations, in relation to 2098 children and adolescents hospitalized for asthma in South-West Sydney, Australia. 79 A notable finding of that study was the increased risk of asthma among boys for grass, although grass, weeds and unclassified pollen were triggers for all children, with those between 2 and 5 years of age being most susceptible. In other work, Guibas et al studied 1207 children hospitalized for flu-like illness in order to assess how infection with influenza virus (IFV) differs from rhinovirus (RV) in relation to acute asthma.…”

“…Both aeroallergens and respiratory viruses are known to exacerbate asthma in children . Shrestha and colleagues looked at the impact of different pollen types according to daily ambient concentrations, in relation to 2098 children and adolescents hospitalized for asthma in South‐West Sydney, Australia . A notable finding of that study was the increased risk of asthma among boys for grass, although grass, weeds and unclassified pollen were triggers for all children, with those between 2 and 5 years of age being most susceptible.…”