Abstract
Background: Pulmonary eosinophilia (PE) occurs due to various causes, such as infections, drugs, autoimmune processes, and obstructive lung diseases. Infiltration of eosinophils is found in the airways, interstitium and alveoli, resulting inflammation and tissue injury. The airway secreted mucins MUC5AC and MUC5B may be associated with the pathogenesis of PE; MUC5AC production can be increased by eosinophils, and MUC5B plays a role in an ameliorating pathway for eosinophilia. However, the composition of the airway secreted mucins in PE has not been evaluated yet.
Aims: To determine the concentrations of the airway secreted mucins MUC5AC and MUC5B in patients with pulmonary eosinophilia.
Methods: Diagnostic BAL was performed via fiberoptic bronchoscopy according to established guidelines. After the BAL, patients who met criteria for PE (elevated BAL eosinophil count greater than 25%, chronic eosinophilic pneumonia with asthma n=5, drug-induced pneumonia n=2, acute eosinophilic pneumonia n=1) and patients who showed no apparent lung disease (control, n=8) were enrolled to this study. The absolute concentrations of MUC5AC and MUC5B in BAL fluids were measured by ELISA.
Results: The mean percentage of eosinophils in BAL fluids in PE was 63±24%. The concentrations of mucins in PE with chronic eosinophilic pneumonia were significantly higher with MUC5AC, and significantly lower with MUC5B, respectively, as compared with controls (p<0.05). The high MUC5AC/MUC5B ratio was observed in PE with asthma.
Conclusions: The composition of the airway secreted mucins MUC5AC and MUC5B in PE patients was altered, which may be involved in the pathogenesis of eosinophilic airway inflammation, especially with asthma.
Footnotes
Cite this article as: European Respiratory Journal 2019; 54: Suppl. 63, PA4390.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2019