Sputum Induction techniques preferentially sample a specific region of the lung. Sputum samples reflect events on the surfaces of the large bronchial/central airways (vs distal alveolar region). This is noteworthy since this is the site that is proximal to many respiratory diseases’ pathology and therefore provides opportunities to better understand these diseases and ultimately provide precision therapeutic target areas.
The analysis of cytokines and mediators in sputum supernatants may be affected by endogenous proteases and the processing of sputum with dithiothreitol(DTT). Sputum extraction with PBS or the addition of protease inhibitors has been suggested to improve the recovery of mediators from sputum supernatants. Depending on the antibodies used, the effect of these interfering factors may also vary with the analytical platforms. In this study we focused on a number of potent pro-inflammatory mediators and their expression following several processing methods in CF, COPD, asthma and healthy controls using single-plexELISA (Life Technologies, UK) and multi-plexRANDOX investigator platforms.