Noninvasive assessment of cytokines in occupational respiratory diseases

A major goal in studying occupational respiratory diseases is to show relationships between occupational exposures and health outcomes. Due to the nature of these diseases, accurate, practical, and objective measurement techniques are needed in field investigations. Pulmonary function tests, such as spirometry, are important objective health outcome measures. However, they reflect the functional changes of the lung, often in relatively late stages, which may be irreversible. Direct monitoring of airways inflammations, in response to occupational exposures, are receiving an increasing attention since they may pick up inflammatory changes before the injury becomes irreversible. Invasive approaches such as bronchoalveolar lavage and bronchial biopsies have been used to assess airways inflammation: but these methods are not practical for use in occupational field investigations. Thus, much work has focused on the development of noninvasive methods for monitoring inflammation in occupational respiratory diseases. The three recent most commonly used noninvasive techniques in occupational respiratory diseases investigations are induced sputum, exhaled breath condensate, and nasal lavage. In this review, we discuss the practical application of these techniques, patents and cytokines measured with them. Since variation of cytokine genes contribute to the inflammatory processes, we briefly discuss the genetic polymorphisms on the expression of occupational respiratory diseases. Details of genetic polymorphism were beyond the focus of this review. Our primary focus was cytokines measured with these three noninvasive techniques in occupational respiratory investigations.