[Diagnostic value of secretory products of eosinophils and neutrophils in bronchoalveolar lavage in patients with idiopathic lung fibrosis].

Idiopathic pulmonary fibrosis (IPF) is characterized by a chronic inflammatory process in the lower respiratory tract of unknown etiology and poor prognosis. There is evidence that cytotoxic mediators released by neutrophils and eosinophils, such as myeloperoxidase (MPO) and eosinophil cationic protein (ECP) play a central role in the pathogenesis of this disease. The aim of this study was to assess disease activity in patients with IPF by measuring MPO and ECP concentrations in bronchoalveolar lavage (BAL). 14 patients with IPF had significantly higher concentrations of BAL-MPO and ECP (median = 117.2 micrograms/l, range: 4-217 micrograms/l and median = 16 micrograms/l, range: 4-34 micrograms/l, respectively) than patients with sarcoidosis (n = 9) (median = 6.5 micrograms/l, range: 4-12 micrograms/l and median = 7.1 micrograms/l, range: 2-13 micrograms/l, respectively) or pneumonia (n = 13) (median = 10.8 micrograms/l, range: 5-14 micrograms/l and median = 7.6 micrograms/l, range: 3-10 micrograms/l, respectively) (p < 0.01). Follow-up of MPO and ECP concentrations in BAL was performed in 8 patients with IPF before and after 4 weeks high-dose and 12 months low-dose corticosteroid therapy. Changes in MPO and ECP levels paralleled the clinical course and successful treatment resulted in a significant decrease of both MPO and ECP concentrations (p < 0.05), while clinical deterioration or treatment failure was associated with an increase of BAL-MPO and ECP levels. Increased MPO and ECP concentrations in BAL seem to reflect ongoing disease activity and may be useful prognostic markers in the management of patients with IPF.