Markers of Fibrosis and Inflammation in Exhaled Breath Condensate (EBC) and Bronchoalveolar Lavage Fluid (BALF) of Patients with Pulmonary Sarcoidosis: A Pilot Study

Introduction: Sarcoidosis is a disease of unknown aetiology. Little is known of the predictive factors of fibrosis. It has been suggested that PAI-1, uPA, TGF-β1, VEGF, IL-8, TNF-α influence this process. The aim of the study was to assess airway inflammatory and fibrosis markers in EBC in sarcoidosis and the effects of fibreoptic bronchoscopy (FOB), bronchoalveolar lavage fluid (BALF), transbronchial lung biopsy (TBLB) and bronchial mu- cosa membrane biopsy on their production in the airways. Material and methods: The study group consisted of 11 patients (five women, six men, mean age 40 ± 9 yrs, mean ± SD) with sarcoidosis stage I–III. PAI-1 (ng/mL), uPA (ng/mL), TGF-β1 (pg/mL), VEGF (pg/mL), IL-8 (pg/mL), TNF-α (pg/mL) levels were measured in BALF and EBC collected before, and 48 h after, FOB. Results: No significant changes in EBC levels of VEGF, PAI-1, TGF-β1, TNF-α (respectively: 8.02 ± 4.97 pg/mL; 1.1 ± 1.2 ng/mL; 2909.7 ± 206.6 pg/mL; 10.7 ± 19.9 pg/mL) after FOB were observed when compared to baseline. In contrast, IL-8 concentration in EBC (pg/mL) decreased after FOB (0.073 ± 0.13 vs. 0.061 ± 0.1, p = 0.006) and was significantly lower than in BALF (BALF 0.95 ± 0.62, p < 0.05). Also, the mean level of VEGF was higher in BALF than in EBC both pre- and post- FOB (BALF 66.38 ± 36.95, EBC pre-FOB 6.75 ± 3.67 and EBC post-FOB 8.02 ± 4.97). A significant relationship between TNF-a in post-FOB EBC and BALF was also shown (β = 0.63, p = 0.04). Conclusions: FOB does not significantly affect levels of airway inflammation and fibrosis markers present in EBC before and after FOB; they were also comparable to the concentrations marked by BALF. The lack of correlation between marker levels in EBC and BALF indicates that these methods are not equivalent. Due to the possibility of repetition, and the less invasive, simpler method of the EBC test, it would seem reasonable to continue this research on a larger number of patients.