In chronic airway disease, mucus secretion in increased, but extraction of mucin, which is the main component of mucus secretion, is a very complicated and limited in clinical use. Recently, monoclonal antibody for mucin was developed for possible clinical use. In this study, cellular analysis and quantification of respiratory mucin in sputum of patients with chronic airway diseases were performed.

Sputum was collected from patients with asthma(n=33), bronchiectasis(n=8) or chronic bronchitis(n=13) by spontaneous expectoration or by hypertonic saline induction, Collected sputums was treated by 0.1% dithiotreitol to dissociate the disulfide bond of the mucus and filtered through a nylon gauze. Total cell count, viability and differential count were measured. For detection of mucin, collected samples were treated with sodium dodoecyl sulfate polyacrylamide gel electrophoresis and then with monoclonal antibody(HMO2), as the primary antibody, and PAS stain. The amount of mucin was measured with ELISA by HMO2. Correlation with clinical information, cellular analysis, and amount of measured mucin were analyzed.

Total cell counts of sputum were significantly increased in patients with bronchiectasis but viability remained the same. Eosinophils were significantly increased in patients with asthma, neutrophils in bronchiectasis chronic bronchitis, respectively (p<0.05). The results of Western blotting and PAS staining confirmed the presence of glycoproteins and matched? with mucin. The amounts of mucin measured by ELISA were not significantly different among the disease groups. Significant correlation was identified between the amount of mucin and viability(r=-0.482, p<0.05).

Inflammatory cells in the sputum of those with chronic airway disease were different for each disease type. Measurement of mucin by ELISA via monoclonal antibodies may be a simple method for the evaluation of chronic airway disease.