Comparison of airway mucin 5AC and 5B expression in preterm-born adults and asthma.

Background: As preterm birth is a risk factor for developing chronic lung disease later in life and has been associated with asthma-like symptoms, we hypothesised that preterm-born adults with and without a history of bronchopulmonary dysplasia (BPD) resemble patients with asthma with respect to altered mucin expression in the airways. Methods: Bronchial biopsies were retrieved from 39 adults born very-to-extremely preterm (of which 22 had a history of BPD), 18 adults with mild allergic asthma and 24 healthy controls. Mucin (MUC) 5AC and MUC5B protein expressions were determined by immunohistochemistry and immunoelectron microscopy. Additionally, the percentage of goblet cells was estimated. Results: MUC5AC expression and the percentage of goblet cells were lower in preterm-born adults than in asthma patients but did not markedly differ from those of healthy controls. In the preterm-born adults, MUC5AC expression correlated negatively with forced expiratory volume in 1 s to forced vital capacity ratio (FEV Conclusions: Unlike patients with asthma, preterm-born adults with or without BPD do not exhibit increased MUC5AC expression compared with healthy controls. However, the associations of MUC5AC and MUC5B expression with lung function, symptoms and quality-of-life indices suggest a potential clinical role for these mucins in this population.