An increased asthma risk continued until young adulthood after early-childhood hospitalisation for wheezing

Association of Wheezing Requiring Hospitalization Before 2 Years of Age With Autoimmune Diseases During Childhood: A 15-Year Follow-up Study From Birth

PURPOSE

Wheezing in early life is most frequently caused by viral lower respiratory tract illnesses, constituting a significant disease burden in children. This study aimed to investigate the association of wheezing in early life with autoimmune diseases throughout childhood.

METHODS

A population-matched retrospective cohort study was conducted in Korea between 2002 and 2017. The cohort comprised 34,959 children admitted with viral wheezing before 2 years of age and an equal number of the matched unexposed children born in 2002 and 2003. Exposed infants were defined as those hospitalized for bronchiolitis or bronchial asthma before the age of 2. Unexposed controls were matched by sex and birth year at a 1:1 ratio, using incidence density sampling. A Cox proportional hazard model controlled for multiple risk factors was employed.

RESULTS

The median age at hospitalization for wheeze was 9 months (interquartile range, 5-15 months), and 63% of the exposed infants were male. Over the mean 15-year follow-up period, the incidence rate of autoimmune diseases was 74.0 and 62.2 per 10,000 person-years in the exposed and matched unexposed cohorts, respectively. The adjusted hazard ratio for any autoimmune disease in the exposed cohort was 1.15 (95% confidence interval, 1.09-1.23) in comparison with the unexposed cohort. The exposed cohort revealed an augmented risk for specific autoimmune diseases, including juvenile idiopathic arthritis, Kawasaki disease, Henoch-Schönlein purpura, psoriasis, idiopathic thrombocytopenic purpura, and immunoglobulin A nephropathy. Risks were heightened for children with multiple wheezing episodes or a persistent wheezing episode after the age of 2 years.

CONCLUSIONS

This research identifies associations between early-life wheeze and the development of autoimmune diseases in childhood. Understanding these relationships can aid in recognizing the underlying pathophysiology of early-life wheeze and childhood autoimmune diseases, contributing to management strategies for these conditions.

Bronchiolitis, Regardless of Its Etiology and Severity, Is Associated With Increased Risk of Asthma: A Population-Based Study

An association exists between severe respiratory syncytial virus (RSV)-bronchiolitis and a subsequent increased risk of recurrent wheezing (RW) and asthma. However, a causal relationship remains unproven. Using a retrospective population-based cohort study (339 814 children), bronchiolitis during the first 2 years of life (regardless of etiology and severity) was associated with at least a 3-fold increased risk of RW/asthma at 2-4 years and an increased prevalence of asthma at ≥5 years of age. The risk was similar in children with mild bronchiolitis as in those with hospitalized RSV-bronchiolitis and was higher in children with hospitalized non-RSV-bronchiolitis. The rate of RW/asthma was higher when bronchiolitis occurred after the first 6 months of life. Our results seem to support the hypothesis of a shared predisposition to bronchiolitis (irrespective of etiology) and RW/asthma. However, 60% of hospitalized bronchiolitis cases in our setting are due to RSV, which should be paramount in decision-making on imminent RSV prevention strategies.

Respiratory syncytial virus, recurrent wheeze and asthma: A narrative review of pathophysiology, prevention and future directions

Globally, respiratory syncytial virus (RSV) is the leading cause of bronchiolitis and pneumonia in young children, and the association between severe RSV disease and later recurrent wheeze and asthma is well established. Whilst a causal link between RSV and wheeze/asthma is not yet proven, immunological evidence suggests skewing towards a Th2-type response, and dampening of IFN-γ antiviral immunity during RSV infection underpins airway hyper-reactivity in a subset of susceptible children after RSV infection. Age at primary RSV infection, viral co-infection and genetic influences may act as effect-modifiers. Despite the significant morbidity and mortality burden of RSV disease in children, there is currently no licensed vaccine. Recent advancements in RSV preventatives, including long-acting monoclonal antibodies and maternal vaccinations, show significant promise and we are on the cusp of a new era in RSV prevention. However, the potential impact of RSV preventatives on subsequent wheeze and asthma remains unclear. The ongoing COVID-19 pandemic and associated public health measures have disrupted the usual seasonality of RSV. Whilst this has posed challenges for health-care services it has also enhanced our understanding of RSV transmission. The near absence of RSV cases during the first year of the pandemic in the context of strict public health measures has provided a rare opportunity to study the impact of delayed age of primary RSV infection on asthma prevalence. In this review, we summarise current understanding of the association between RSV, recurrent wheeze and asthma with a focus on pathophysiology, preventative strategies and future research priorities.