Induced Sputum Study Via Inhalation of Hyperosmolar Saline to Investigate Airway Inflammation in Asthma: Method of Induced Sputum Study and Examination of Inflammatory Cells

Kang, Suck Min; Kim, Chul Woo; Park, Joong Won; Hong, Chun Soo

Abstract

OBJECTIVES
From asymptomatic asthmatic patients unable to produce sputum spontaneously, we performed a non-invasive method obtaining sputum via inhalation of ultrsonically nebulised hyperosmolar saline(3%) which provides a way to investigate airway inflammation, And we also evaluated the effectiveness of the ultrasonic nebulizer in these patients.
METHODS
50 asymptomatic patients unable to produce sputum spontaneously inhaled a hyperosmolar saline via an Ultrasonic nebulizer to induce sputum. We examined the quality of the sputum, total cell counts and differential cell counts of eosinophil after sputum processing.
RESULTS
1) The quality of the sputum was uninterpretable (12%); poor(16%); fair(34%); good(38%), repectively. The mean induction time of expectoration was about 10 minutes. 2) The most common complaint was of a salty taste(45 cases). The mean fa11 in peak expiratory flow rate during inhalation of saline was 4.0% and the fall more than 20% was observed in 5 cases. 3) The mean eosinophil percent in induced sputum was 38.5%, The mean value of the total IgE and total peripheral eosinophil count was 818.2 IU/ml, 401.2/mm3 respectively, 4) There were no relationships between the sputum eosinophil count(%) and both the total IgE and the PC20(r=0.13, r=0.18). There was also an insignificant correlation between the sputum eosinophil count(%) and the total peripheral eosinophil count(r=D.22).
CONCLUSION
We find that there are many eosinophils within induced sputum via inhalation of ultrsonically nebu1ised hyperosmolar saline from asymptomatic asthmatic patients unable to produce sputum spontaneously, Therefore we suggest that an induced sputum study via inhalation of hyperosmolar saline is useful to determine a patient`s status of airway inflammation.