抄録
Background: Clinical and experimental studies were performed to investigate the kinetics of fibronectin (FN) and its clinical significance in bronchial asthma.
Methods: Measurements of plasma fibronectin (PFN) and sputum fibronectin (SFN) were performed in asthmatic patients. Eosinophil chemotaxis, adherence and activation activity to FN were measured. An animal model of bronchial asthma was created and lung tissues were analyzed by immunohistochemical staining.
Results: Compared with periods without an asthmatic attack, the PFN level was significantly lower during periods with more severe asthmatic attacks in 15 patients with bronchial asthma. In contrast, the SFN level was significantly higher during periods with more severe asthmatic attacks. In a guinea pig model of asthmatic bronchitis, FN was positively stained in the subepithelial or submucosal tissue and abraded epithelial cells in the alveolar space during asthmatic attacks. Marked eosinophilic infiltration was also noted in the same tissues and cells. A negative correlation was noted between the number of peripheral eosinophils and the PFN level. In contrast, a positive correlation was noted between the number of sputum eosinophils, which reflects the severity of asthmatic attacks, and the SFN level. An experimental study was performed to investigate the relationship between eosinophils and FN. A positive relationship was noted between eosiophil chemotaxis, increased adherence of activated eosinophils and FN levels.
Conclusions: It is suggested that FN may enhance allergic reactions at an early or acute phase of bronchial asthma.
