[Vitronectin in bronchoalveolar lavage--a parameter of disease activity in sarcoidosis]

Vitronectin is a multifunctional glycoprotein which is involved in several of the processes of inflammation and repair. In previous studies we demonstrated that increased concentrations of vitronectin can be detected in bronchoalveolar lavage fluids (BAL) of patients with interstitial lung disease (e.g. sarcoidosis). The outcome of sarcoidosis is generally favorable, however, some patients progress to pulmonary fibrosis. There is a need for markers indicating early fibrotic changes in the lung in patients with sarcoidosis. The present study was designed to evaluate the potential of BAL-vitronectin measurements for the assessment of disease activity in subjects with sarcoidosis. BAL-vitronectin concentrations were determined in 19 patients with biopsy proven sarcoidosis and sequential analysis of BAL-vitronectin levels were performed in 11 patients before and after therapy. Patients with active sarcoidosis had higher BAL-vitronectin concentrations (1.56 +/- 0.89 microgram/ml) than patients with inactive disease (0.68 +/- 0.33 microgram/ml; p < 0.01). Patients with active sarcoidosis received high-dose glucocorticoid treatment for four weeks followed by low-dose glucocorticoid therapy for eleven months. After high-dose medication BAL-vitronectin concentrations fell significantly (1.08 +/- 0.9 microgram/ml; p < 0.01). A further decrease in vitronectin levels resulted when therapy was continued for a year (0.75 +/- 0.48 micrograms/ml). Clinical deterioration correlated with an increase in BAL-vitronectin concentrations. Thus, measurement of BAL-vitronectin levels might be a useful marker for assessing disease activity and response to therapy in patients with sarcoidosis, but does not provide prognostic information.