The Role of Endothelium A and EGFR Receptor in Fibrocytes From Asthma With Obstructive Sleep Apnea
The Role of Endothelium A and EGFR Receptor in Fibrocytes From Asthma With Obstructive Sleep Apnea
The investigators will compare the circulating fibrocyte proportion in asthmatic patients
 with obstructive sleep apnea (OSA) and not with OSA In addition, the investigators will
 compare the expression of epidermal growth factor receptor (EGFR), endothelin A receptor
 (ETAR) and connective tissue growth factor (CTGF) The association of those factors and annual
 decline of forced expiratory volume in 1 second (FEV1) will be performed
Asthma is characterized by airflow obstruction, chronic airway inflammation and remodeling.
 The investigators' report has shown directly the relationship between fibrocytes, and chronic
 airflow obstruction with rapid decline in FEV1 in asthma. Asthma concomitant of obstructive
 sleep apnea (OSA) may appear intermittent hypoxia and result in the frequent attack of asthma
 symptoms. In animal model, hypoxia may increase the circulating fibrocytes, thus play a role
 in pulmonary hypertension. The investigators' published paper also showed that an increased
 expression of EGFR, ETAR and Vascular endothelial growth factor receptor (VEGFR) in
 circulating fibrocytes in chronic obstructive asthmatics. It is unknown whether circulating
 fibrocytes from asthma with OSA have the higher expression of EGFR, connective tissue growth
 factor receptor, VEGFR and ETAR compared to asthma without OSA. The investigators are also
 interested in whether proliferation and differentiation of fibrocytes are different between
 asthmatics with or without concomitant of OSA. The investigators will study the correlation
 between the percentage of circulating fibrocytes and the oxygen desaturation index (ODI) and
 severity of sleep apnea to clarify the role of hypoxia, which contributing to chronic asthma.
Inclusion Criteria:

 -  clinical diagnosis of asthma

 Exclusion Criteria:

 -  chronic obstructive pulmonary disease (COPD)

 -  bronchiectasis

 -  cystic fibrosis