sTREM-1 in bronchoalveolar lavage fluid in patients with pulmonary sarcoidosis, effect of smoking and inflammation

Soluble TREM-1 (sTREM-1; Triggering receptor expressed on myelocytes) is a new inflammatory marker indicating the intensity of myeloid cells activation and the presence of infection caused by extracellular bacteria and mould. The aim of our work was to detect and compare the levels of sTREM-1 in bronchoalveolar lavage fluid (BALF) in patients with pulmonary sarcoidosis (PS) and other ILD of non-infectious origin. The sTREM-1 levels were assessed by ELISA in 46 patients suffering from ILD, out of them 22 with PS. The levels of BALF sTREM-1 in PS patients were higher than in control group of ILD patients of non-infectious origin, however, the difference was not statistically significant. Since all PS patients except one were nonsmokers we compared non-smokers PS with non-smokers ILD patients and found four times higher levels of BALF sTREM-1 in PS patients (P = 0.001). We also recorded the effect of smoking, ILD smokers had higher sTREM-1 levels than non-smokers (P = 0.0019). Higher concentrations of sTREM-1 were detected in BALF of patients with lymphadenopathy and with elevated inflammatory markers in BALF. Our results show that BALF sTREM-1 could be a good inflammatory marker and could help in diagnosis and PS monitoring. Detection of sTREM-1 in BALF indirectly points to myeloid cells activation in the lungs and helps to complete the information about the number of myeloid cells commonly determined in BALF with additional information concerning the intensity of their activation. This is the first study that analyses BALF sTREM-1 levels in patients with PS (Tab. 8, Ref. 28). Text in PDF www.elis.sk.