BAL, an important tool in assessing occupational lung diseases, is an invasive technique and thus unsuitable for screening programmes, the evaluation of exposure and the monitoring of hazardous dust.
Examination of induced sputum is a noninvasive method to directly study particulate burden and inflammatory processes in the lung.
The correlation between cells retrieved by BAL and induced sputum shows different proportions of leukocytes, but similar eosinophil cell counts and qualitative/quantitative analyses of particles.
Many accumulating lines of evidence have shown that the eosinophil count is a useful marker for monitoring OA.
To introduce induced sputum methodology in the field of occupational lung diseases.
To describe the eosinophil count as a method of monitoring occupational asthma.
To explain how to use quantitative and qualitative analysis of inhaled particles in hazardous dust exposure.
Summary Induced sputum is a particularly promising procedure, since it provides specific information on both the cellular and molecular constituents in inflammation. In the period 1950–1970, sputum cells were examined on stained smears in both research and clinical settings. After their recovery by spontaneous coughing, the cells were used to study lung cancer and respiratory infections, and, later on, to diagnose Pneumocystis carinii pneumonia in patients infected with HIV. The method was widely improved upon by the induction of sputum with aerosol of hypertonic saline, and then extended to become part of the assessment of airway inflammation in bronchial asthma and COPD. However, less attention was given to the use of induced sputum in occupational exposures. This review analyses the value of induced sputum and presents its applications in pulmonary occupational and environmental medicine.
- ©ERS 2005
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