Abstract

Biological markers are commonly used in diagnosis, determination of the response to treatment or adjustment of treatment, determination of recurrence of the disease and prognosis, and also in respiratory medicine research. Determination of volatile substances in exhaled breath is simple and repeatable. However, most of the inflammatory mediators are not volatile and, therefore, are not detectable. Although some procedures, such as bronchial biopsy, lung biopsy, and bronchoalveolar lavage, are routinely used in respiratory medicine, their applicability and repeatability are difficult and they are invasive. The methods in which non-volatile substances were ascertained were limited by induced sputum and bronchoalveolar lavage. However, recently, exhaled breath condensate (EBC) analysis for non-invasive quantification of airway inflammation has become a potentially promising tool in respiratory diseases. Additionally, there is a growing interest in measuring different markers in exhaled breath condensate. An increasing number of studies on inflammatory mediators, oxidative stress indices, heavy or toxic metals, and genetic analysis in EBC have become available in the literature.