Pulmonary febrosis and ferruginous bodies associated with exposure to synthetic fibers

Exposure to synthetic fibers with employment in textile mills can be associated with an elevated risk of interstitial lung disease (ILD). A mechanism of injury has not been determined. ILD can follow exposures to inorganic fibers (e.g., asbestos) which are associated with a mobilization of iron and catalysis of an oxidative stress. We describe 2 patients with ILD associated with exposure to synthetic textile fibers who demonstrated carbon-based ferruginous bodies suggesting an in vivo accumulation of iron by synthetic fibers after deposition in the lung. These iron-laden bodies varied from perfectly linear fibers to almost particulate matter. Linear structures were irregularly interrupted by deposition of iron-abundant material. The capacity of these synthetic fibers to complex iron and generate an oxidative stress is confirmed in vitro.