Researchers identify roots of childhood asthma

The discovery of a team headed by Hans Bisgaard at Gentofte Hospital in Gentofte, Denmark, reveals that childhood asthma is closely intertwined with the behaviour of the immune system early in life – a finding that could open the door to new diagnostics and preventative strategies.

The immune system develops as immune cells begin to respond to different types of microbes from the environment. This early stage of development is critical: any persistent abnormalities can trigger chronic inflammation and may raise the risk of asthma and other allergic diseases.

To flesh out the connection between early-life immunity and asthma, first author Anna Thysen et al. studied a longitudinal cohort of 541 children, by analysing blood samples collected at 18 months and comparing these immune profiles to clinical outcomes at six years of age. The scientists exposed blood cells gathered from the 18 month olds to different molecules from viruses, bacteria and fungi. They observed that neutrophils of the innate immune system from some infants responded too strongly to certain viruses, and these same infants were more susceptible to transient asthma as they approached the age of six. Furthermore, some infants harboured T cells that produced excessive amounts of IL-5 and IL-13 – two pro-inflammatory cytokines associated with asthma – and were more likely to have developed persistent asthma at six years of age.

Thysen et al. speculate that future blood tests to detect abnormal immune signatures in infants might allow for earlier prevention or treatment of childhood asthma.