Concentration of surfactant protein D, Clara cell protein CC-16 and IL-10 in bronchoalveolar lavage (BAL) in patients with sarcoidosis, hypersensivity pneumonitis and idiopathic pulmonary fibrosis

The process of interstitial inflammation, often chronic, goes fluently from alveolitis through granuloma formation to irreversible fibrosis and lung remodeling. Eventually, the loss of functional alveolar units leads to chronic respiratory failure. The pneumoproteins (e.g. SP-D, CC-16) are considered to be markers of interstitial inflammation. We measured BAL concentration of SP-D, CC-16 and IL-10 in patients with sarcoidosis (27), IPF (7) and HP (9). The level of each marker was determined by ELISA specific kit. We found the highest SP-D and CC-16 BAL concentration in patients with the III stage of sarcoidosis (96,67 ng/ml and 31,78 ng/ml, respectively). The lowest SP-D concentration was observed in patients with IPF (76,49 ng/ml), and the lowest CC-16 concentration in patients with HP (21,39 ng/ml). The differences were not statistically significant. In the group of the III stage of sarcoidosis higher SP-D levels were related to higher BAL cytosis and higher percentage of BAL neutrophils, just the opposite as in the IPF and HP group. In the III stage of sarcoidosis and HP, the lower SP-D levels, the lower FEV1 and VC values. The results show, that in acute interstitial inflammation with larger parenchyma engagement (III stage of sarcoidosis) the levels of SP-D were higher then in chronic interstitial inflammation (IPF).