Expression of surfactant protein-A in exhaled breath condensate of patients with chronic obstructive pulmonary disease

Author:              

Publisher: Spandidos Publications

E-ISSN: 1791-3004|13|2|1667-1672

ISSN: 1791-2997

Source: Molecular Medicine Reports, Vol.13, Iss.2, 2016-01, pp. : 1667-1672

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

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Abstract

Pulmonary surfactant protein A (SP-A) has been associated with host defense in the lung, and contributes to the pathogenesis of chronic obstructive pulmonary disease (COPD). The present study aimed to determine a noninvasive method of measurement of SPA, and further examine the expression levels of SPA in patients with COPD. SPA was detected in the exhaled breath condensate (EBC) obtained from patients with COPD and from nonCOPD subjects. The individuals recruited for the present study comprised 60 subjects with and without COPD, who underwent lobectomy for a solitary peripheral lung nodule. EBC was collected using a condenser, and an enzymelinked immunosorbent assay (ELISA) was used to measure the levels of SPA. Tissue samples were obtained during lobectomy through resection of the adjacent lung tissues, located >5 cm from the nodule. Western blot analysis and immunohistochemistry were used to measure SPA and SPApositive type II pneumocytes. The results demonstrated that SPA was detectable in the EBC of all subjects. The results of the ELISA and western blotting demonstrated that the expression levels of SPA were significantly decreased in patients with COPD, compared with the nonCOPD subjects. The reduction of SPApositive type II pneumocytes was associated with the expression levels of SPA. Decreased expression levels of SPA in EBC were associated with a higher degree of airway limitation. These results suggested that the measurement of SPA levels in the EBC may serve as a method for monitoring airway obstruction in patients with COPD. Further investigations are required in order to examine these observations further and to elucidate the underlying mechanisms.