Childhood wheezing phenotypes and FeNO in atopic children at age 8

Abstract

Fractional exhaled Nitric Oxide (FeNO) is a surrogate biomarker of the degree of eosinophilic airway inflammation. Using longitudinal latent class analysis, five wheezing phenotypes have been identified, characterized by different ages of onset and prognosis. To assess FeNO measured at 4 and 8years in children with different phenotypes of wheeze and atopy. Children participated in the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) study, a prospective birth cohort in the Netherlands. Respiratory health was assessed yearly by questionnaires until the age of 8years; these data were used to identify five wheezing phenotypes. Associations between FeNO and wheezing phenotypes were investigated using weighted linear regression. Data on wheezing phenotypes and FeNO at 4 and 8years were available in 588 and 973 children respectively. Compared with the phenotype of never and transient wheeze, FeNO at 4years was higher in intermediate onset and persistent wheeze. FeNO at 8years of age differed significantly between all phenotypes, with highest FeNO values for persistent, intermediate onset, and late onset wheeze. Rise in FeNO from 4 to 8years in intermediate and late onset wheezers was significantly higher compared to FeNO rise in never and transient wheezers. Stratified analyses showed that the increase in FeNO in persistent, intermediate, and late onset wheeze was only present in children with allergic sensitization at 8years. The FeNO measured at 8years was associated with specific wheezing phenotypes, only among atopic children.