Inflammatory markers in the exhaled breath condensate of patients with pulmonary sarcoidosis.J Physiol Pharmacol. 2006 Sep; 57 Suppl 4:335-40.JP
Pulmonary sarcoidosis may progress to fibrosis in some patients, so that close monitoring of its activity is essential for recommending clinical strategy. Examination of airway inflammatory markers in bronchoalveolar lavage (BAL) is one of the methods applied to assess the disease severity. Recently, the expired breath condensate (EBC) has become another source of cytokines and mediators. In sarcoidosis, except for NO and oxidative stress markers, no other mediators have yet been estimated in the exhaled air. In the present study we attempted to answer the question of whether airway inflammatory markers in pulmonary sarcoidosis patients might be assessable in EBC and to what extend these markers might reflect the disease activity in the lungs IL-6, TNF-alpha, PAI-1, and IGF-1 were measured by Elisa method in EBC and BALF samples from 9 patients with newly-diagnosed pulmonary sarcoidosis. TNF-alpha, IGF-1, and PAI-1 levels in EBC and BAL samples were comparable and closely positively correlated [TNF-alpha (r=0.79, P<0.001), IGF-1 (r=0.94, P<0.001), and PAI-1 (r=0.81, P<0.001)]. In contrast, IL-6 concentration in EBC was significantly lower compared with that in BALF, while the correlation between both materials was negative (r=-0.47, P<0.05). An important distinction in IL-6 performance, which might explain this inconsistency, is its tendency to form more complex molecular forms of a higher weight than that of other cytokines. Our study shows that EBC reflects cytokine production in the lung as effectively as BALF, providing that the characteristics of proteins evaluated allow their easy transfer into the exhaled air. Further studies are required before accepting EBC samples as an equivalent to BALF.