Serum YKL-40 as a candidate biomarker for hypersensitivity pneumonitis

Background: YKL-40, a chitinase-like protein mainly secreted by macrophages, is increased in serum of several interstitial lung diseases (ILD) and sarcoidosis. The role of YKL-40 as biomarker in hypersensitivity pneumonitis (HP), a T-cell-driven granulomatous lung disease, is still unknown. The aim of our study was to evaluate the role of serum YKL-40 as biomarker for HP. Patients and methods: 175 ILD patients (75 HP, 21 COP, 34 iNSIP and 45 IPF) and 60 healthy controls (HC) were studied retrospectively. Serum YKL-40 was measured by ELISA at baseline and in 39 HP patients in follow up. We evaluated the correlati…