Figure 4

Immunohistochemical staining for caveolin 1 in lung tissue sections. Left: Control tissue from a lobectomy specimen (left lower lobe) with positive staining of alveolar epithelium, endothelium and smooth muscle cells and minimal staining of the bronchiolar epithelium. Right: One representative sample of an obliterative bronchiolitis (OB) lesion from the right lower lobe, with some staining of the cellular infiltrate partially obliterating the bronchiole. In this sample, the staining of bronchiolar epithelium seems slightly increased. The staining of alveolar epithelium and endothelium are similar to normal lung tissue. Open arrows indicate the arterial branch. Closed arrows indicate the bronchiole (original magnification, ×100).