ABSTRACT
Prolonged cough is a common problem in patients seen in general practice. Using a simple method of sputum induction and processing of sputum samples, we determined whether eosinophilic airway inflammation could be a cause of undiagnosed prolonged cough. Eighty-two patients who had had cough for more than 1 month were enrolled into the study, in six primary healthcare centres. Patients with known pulmonary disease, including asthma or chronic obstructive pulmonary disease (COPD), or who were known to have another cause of cough, or to have recently suffered from a respiratory infection, were excluded. Fifty-three healthy individuals served as controls. Sputum was induced by inhalation of 3% saline. Inflammatory cells in smears were studied semi-quantitatively. Concentrations of eosinophil cationic protein (ECP), eosinophil peroxidase (EPO), myeloperoxidase (MPO) and human neutrophilic lipocalin (HNL) were determined. Sputum induction proved safe and adequate samples were obtained from 91%. Sputum eosinophilia (eosinophils accounting for more than 5% of all cells in smears) was present in 14 patients with prolonged cough (19%) but in no healthy individual (P=0.001). Five of the 14 individuals (36%) who exhibited sputum eosinophilia appeared to have asthma, while nine of the 14 (64%) did not. Concentrations of ECP and EPO were higher in patients with prolonged cough than in healthy individuals (P=0.02 for ECP; 0.005 for EPO). We conclude that eosinophilic airway inflammation is a fairly common cause of prolonged cough, even in patients not suffering from asthma or COPD, or in whom no other cause of cough is known to be present. Induced sputum samples obtained in health centres can be studied in a central laboratory. Detection of eosinophilic airway inflammation could aid the decision regarding treatment.
Subject(s)
Acute-Phase Proteins , Cough/etiology , Eosinophilia/complications , Oncogene Proteins , Respiratory Tract Diseases/etiology , Ribonucleases , Adolescent , Adult , Aged , Aged, 80 and over , Biomarkers/analysis , Blood Proteins/analysis , Carrier Proteins/analysis , Case-Control Studies , Chronic Disease , Cough/blood , Eosinophil Granule Proteins , Eosinophil Peroxidase , Eosinophils/pathology , Female , Humans , Inflammation , Leukocyte Count , Lipocalin-2 , Lipocalins , Male , Middle Aged , Peroxidase/analysis , Peroxidases/analysis , Proto-Oncogene Proteins , Respiratory Tract Diseases/blood , Sputum/immunologyABSTRACT
A study was made of effects of two antihistamines, terfenadine (60 mg twice daily) and astemizole (10 mg once daily) on wheals induced by histamine dihydrochloride (10 mg/ml) in the prick test on the upper back of 15 healthy students. The suppressive effects of terfenadine on the histamine wheal appeared earlier (2 h), and disappeared earlier (within 1 day) than those of astemizole (3 days and 28 days, respectively). No difference between the maximal effects of the two drugs was seen.
