Methods:
Enrolled children were subjected to full history taking with paying particular attention to intermittent cough attacks, expectoration, wheezy dyspnea and chest tightness. In order to detect tachypnea, signs of hyperinflation, extended expiratory phase and expiratory rhonchi thorogh physical examination was carried out. lung functions assessment by Spirometry (performed by Erich jaejre 95 GmbH 1992-1997 for measurement of pulmonary function) were performed before and after bronchodilator therapy (administrating of total of 400 mcg of short acting B2-agonist salbutamol in four puffs at 30-second intervals by using a spacer device) 11 and measurement of Forced vital capacity (FVC), forced expiratory volume in 1st second (FEV1) and FEV1/FVC and post bronchodilator change in FEV1 automatically displayed by the apparatus.
Laboratory investigations were carried out including complete blood count analyzed by Sysmex Kx-21N with microscopic manual differential count and total serum IgE level measurement by ELISA (DiaMed Eurogen, Turnhout, Belgium). Nasal epithelial cells were collected by brushing the inferior turbinate using a CytoSoft Brush (medical packaging co, Camarillo, Calif, USA). The collected brush was submerged in Nuclease-free H2O and frozen at-80°C until extraction.