Hepatocyte growth factor in exhaled breath and BAL fluid in sarcoidosis

Hepatocyte growth factor (HGF) is a strong mitogen stimulating lung epithelial cell growth. Elevated levels of HGF have been reported in various biological materials of patients with acute respiratory distress syndrome and in patients recovering from pneumonia or pneumonectomy. Sarcoidosis may be complicated by lung fibrosis. Consequently, HGF could be considered a new biomarker identifying patients with a higher risk of lung fibrosis. The aim of the study was to verify whether: 1. HGF is measurable in bronchoalveolar lavage fluid (BALF) and exhaled breath condensate (EBC); 2. HGF in BALF or EBC is impaired in sarcoidosis; and 3. HGF correlates with chosen activity and prognostic markers.

Sixty-four EBC and 30 BALF of sarcoid patients, and 15 and 9 of healthy controls, respectively, were collected for the measurement of HGF using an ELISA test.

HGF was detectable in 62% of EBC samples (56% sarcoidosis and 87% of controls) and in all the BALF samples. EBC and BALF concentrations were not different in comparison to the controls. Moreover, no correlation was found between EBC/BALF concentrations and radiological stage, lung function tests, duration of disease, number of relapses, BALF lymphocytes, serum ACE, or serum and urine calcium concentrations.

HGF is detectable in BAL and EBC. However, it does not distinguish sarcoidosis patients from healthy subjects. The above, as well as the lack of correlations with various parameters of disease activity and severity rule out EBC/ /BALF HGF as a biomarker for sarcoidosis monitoring.