[The use of induced sputum examination in respiratory system diseases]

Induced sputum is a valuable tool enabling thorough evaluation of respiratory system, and it has been increasingly used in pneumonology. The article presents the mechanism of sputum induction and basic differences between induced sputum and BALF. The usefulness of induced sputum in modern oncology and microbiology is discussed, from diagnosing lung cancer and tuberculosis to assessment and monitoring of respiratory tract bacterial flora in chronic lung diseases. The authors describe the role of sputum cell count and fluid-phase analysis in various conditions, like asthma, COPD, non-asthmatic eosinophilic bronchitis (NAEB) and interstitial lung diseases, as well as in estimating occupational exposure for diagnosing occupational respiratory disorders. Basic guidelines for sputum induction methodology are discussed, and indications, contraindications and safety issues presented.