Modern Concepts on the Role of Inflammation in Pulmonary Fibrosis

Context.-Idiopathic pulmonary fibrosis is a uniformly lethal disease with limited biomarkers and no proven therapeutic intervention short of lung transplantation. Pulmonary fibrosis at one time was thought to be a result of inflammation in the lung. Although some forms of pulmonary fibrosis may result from inflammation, idiopathic pulmonary fibrosis is currently thought to result from cell death primarily and inflammation secondarily. Objective.-To determine the role of inflammation in pulmonary fibrosis in light of our laboratory's published and unpublished research and published literature. Data Sources.-Review based on our laboratory's published and unpublished experimental data with relevant background and clinical context provided. Conclusions.-Although cell death is central to pulmonary fibrosis, the proper cytokine environment leading to macrophage polarization is also critical. Evaluation of this environment is promising both for the development of disease biomarkers and for targets for therapeutic intervention. (Arch Pathol Lab Med. 2011;135:780-788)