Figure 5

Blocks of archived lung from autopsies of patients dying without a lung disease showed normal staining for ferritin at the airways and among a few alveolar macrophages (left). Positive staining for ferritin was increased in lung tissue of patients diagnosed with PAP (right). Expression of the protein in the patients with PAP appears to include not only airway epithelium and macrophages but also material filling the alveolar spaces. Magnification approximates 200×.