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Abnormal immune response to pathogenic bacteria in infancy led to asthma

Children who exhibited an abnormal immune response to pathogenic bacteria in infancy were more likely to develop childhood asthma by age 7, according to researchers.

“We hypothesize that an abnormal immune response to bacteria in the airways allows persistent colonization and represents a path to the chronic airway inflammation of childhood asthma,” Jeppe Madura Larsen, PhD, of the Technical University of Denmark in Lyngby and University of Copenhagen, and colleagues wrote.

Their study was part of the Copenhagen Prospective Studies on Asthma in Childhood birth cohort, consisting of 411 children born to mothers with active or previously diagnosed asthma enrolled 1998-2001. Data on H influenzae, M catarrhalis and S pneumoniae were available for 292 children aged 7 years.

Jeppe Madura Larsen

Larsen and colleagues reported that the immune response to pathogenic bacteria was different in infants with asthma by 7 years (P=.0007). Prospective asthmatic patients demonstrated more pronounced aberrant production of interleukin (IL)-5 (P=.008), IL-13 (P=.057), IL-17 (P=.001), and IL-10 (P=.028). Researchers observed no differences, however, in T-cell activation or peripheral T-cell composition.

“Novel strategies to promote appropriate bacterial immunity in infancy might have clinical implications for disease prevention,” the researchers wrote. “We propose that an abnormal immune response to pathogenic bacteria colonizing the airways … might lead to chronic airway inflammation and childhood asthma.”

Disclosure: Susanne Brix, PhD, reports support from the Danish Strategic Research Council. Hans Bisgaard, DMSc, reports support from the Danish Strategic Research Council, the Lundbeck Foundation, the Danish State Budget, the Capital Region of Denmark, and the Danish Council for Independent Research, Medical Sciences.