Serum S100A8 and S100A9 as prognostic biomarkers in acute exacerbation of idiopathic pulmonary fibrosis

Background: Acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is a devastating and life-threatening condition during its clinical course. Biomarkers for precisely anticipating the prognosis of AE-IPF remain to be fully established. The objective of this study was to clarify whether S100A8 and S100A9, which are calcium-binding proteins mainly produced by activated neutrophils, are significant prognostic biomarkers in AE-IPF.Methods: Thirty-seven patients with AE-IPF who were diagnosed and treated at our hospital were retrospectively evaluated. The serum levels of S100A8 and S100A9 were measured using enzyme-linked immunosorbent assay, and the relationships between these levels and clinical parameters or prognosis were evaluated.Results: The serum levels of S100A8 (median 386.5ng/mL) and S100A9 (median 60.2ng/mL) in patients with AE-IPF were significantly higher than those in age-matched healthy controls and in patients at IPF diagnosis (p