Determinants of baseline lung function and bronchodilator response in 4-year-old children.

The prolonged period required for maturation of the respiratory system makes it vulnerable to environmental exposure. This study aimed to investigate the association between early-life factors and lung function in preschool children. Children aged 4 years, who were included in a prospective birth cohort, underwent lung function testing at baseline (n=535) and after bronchodilation (n=498) by forced oscillations. Information on symptoms and exposures was collected through half-yearly questionnaires. Allergen-specific serum IgE was quantified at 1 and 4 years. Multiple linear regression analysis showed that the baseline respiratory resistance and reactance area were larger in the children with previous wheeze, those with early-onset sensitisation to inhalant allergens and those who were smaller. Furthermore, children with previous lower respiratory tract infections exhibited higher baseline resistance values. The baseline resistance was the only independent determinant of the bronchodilator-induced change in resistance, whereas current height and baseline reactance area were independently associated with the change in reactance area. In conclusion, previous lower respiratory tract infections, the timing of previous wheeze, inhalant sensitisation and current height independently influence the baseline lung function of 4-year-old children, whereas baseline lung function is the principal determinant of the bronchodilator response.

A STAT3 mutation in hyper-immunoglobulin E syndrome: A case report.

Hyper-immunoglobulin E syndrome (HIES) is a rare immunologic disorder. This syndrome is caused by mutations in signal transducer and activator of transcription 3 gene. The described case report showed clinical HIES features such as recurrent bacterial pneumonia, lung cysts, characteristic facial features and a newborn dermatitis. We found a clinical features score of 35 and a positive family history, which, together, made a HIES diagnosis very probable. During DNA analysis, a new, formerly unknown, 1067C→G (p.P356R) mutation, with reference sequence NM_139276.2, was found in the DNA binding site of the STAT3 gene. Both the child and his mother were affected. Thus, this family is affected by the autosomal dominant, HIES. This case report reveals a formerly unknown mutation, 1067C→G (p.P356R) in this gene.