Oxidant-mediated epithelial cell injury in idiopathic pulmonary fibrosis.

Publication Type Academic Article
Authors Cantin A, North S, Fells G, Hubbard R, Crystal R
Journal J Clin Invest
Volume 79
Issue 6
Pagination 1665-73
Date Published 06/01/1987
ISSN 0021-9738
Keywords Body Fluids, Hydrogen Peroxide, Macrophages, Neutrophils, Peroxidase, Pulmonary Alveoli, Pulmonary Fibrosis, Superoxides
Abstract Lung inflammatory cells of patients with idiopathic pulmonary fibrosis (IPF) were evaluated for their ability to injure 51Cr-labeled AKD alveolar epithelial cells in the presence and absence of IPF alveolar epithelial lining fluid (ELF). The IPF cells were spontaneously releasing exaggerated amounts of superoxide (O.2) and hydrogen peroxide (H2O2) compared with normal (P less than 0.02). Cytotoxicity of the AKD cells was markedly increased when the IPF inflammatory cells were incubated with autologous ELF (P less than 0.02). The majority of IPF patients had ELF myeloperoxidase levels above normal (P less than 0.002). Incubation of IPF ELF with AKD cells in the presence of H2O2 caused increased cellular injury (P less than 0.01 compared with control), which was suppressed by methionine, a myeloperoxidase system scavenger. IPF patients with high concentrations of ELF myeloperoxidase deteriorated more rapidly than those with low ELF myeloperoxidase (P less than 0.05). Thus, IPF is characterized by an increased spontaneous production of oxidants by lung inflammatory cells, the presence of high concentrations of myeloperoxidase in the ELF of the lower respiratory tract, and a synergistic cytotoxic effect of alveolar inflammatory cells and ELF on lung epithelial cells, suggesting oxidants may play a role in causing the epithelial cell injury of this disorder.
DOI 10.1172/JCI113005
PubMed ID 3034979
PubMed Central ID PMC424497
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