Investigation of the surfactant protein D expression in airways of patients with severe persistent asthma

Asthma is a chronic inflammatory disorder that host immune system has an important role in its development. In this regard, surfactant protein D (SP-D), a lipoprotein complex secreted by the pneumocyte type ۲, is involved in the innate immune response. It facilitates phagocytosis of pathogensvia opsonization. Therefore, this study was conducted to determine the gene expression level of SP-D among patients diagnosed with severe persistent asthma Methods: This cross-sectional study was conducted on ۲۵ severe persistent asthmatic patients who were admitted to a specialized clinic for pulmonology, Mashhad, Iran, between ۲۰۱۸ and ۲۰۱۹. Convenience sampling was utilized to select the participants. Patients aged at least ۱۸ years, diagnosed with severe asthma, uncontrollable by high dose Inhaled Corticosteroids, Long-Acting Beta-Agonists and anti-leukotriene and, forced expiratory volume in one second (FEV۱) under ۸۰%, were included. Patients with a history of corticosteroid allergy and interaction, diagnosed gastroesophageal reflux disease, severe cardiac disease, pneumonia, obstructive sleep apnea, chronic obstructive pulmonary disease, were excluded. To assess the geneexpression level of SP-D in the airways of patients with severe persistent asthma, we performed a real-time polymerase chain reaction (RT-PCR). RT-PCR was evaluated the mRNA expression of SP-D in the cells from sputum specimens. hypertonic saline was used to inducing septum production as a tool for obtaining inflammatory cells from the airways of patients. Data were analyzed by SPSS version ۲۰ using Mann-Whitney U test. The significance level in this study was <۰.۰۵.

کلیدواژه ها:

Asthma ، Surfactant protein D ، Airway ، Gene expression ، RT-PCR