Figure 3

Hbα and Hbβ expression and localization in representative sections in control, COPD and IPF lungs (A, B, magnification 900×). Positive Hbα and Hbβ expression was seen mainly in the alveolar epithelium as well as in macrophages in the control and COPD lungs. The alveolar epithelium (arrows) of patients with IPF displayed very weak staining in contrast to the situation in controls and patients with COPD. Both Hb stainings were low or absent in the fibrotic areas and fibroblast foci. Morphometrical analyses (magnifications 300×), which were conducted by excluding blood vessels and macrophages, show the sum of positive bronchiolar/alveolar epithelium and interstitium (Epi+Int) (C). Hbα and Hbβ positive area in bronchiolar/alveolar epithelium only was evaluated separately by excluding blood vessels, macrophages and interstitium (Epi) (D). Morphometrical analyses were evaluated from 6 control, 7 COPD and 7 IPF lung tissues. For detailed data see Additional files 1 and 2 (Tables S1 and S2; as shown in the Tables two or three representative areas were analyzed from all stained sections). Data are presented as mean ± SEM. For patient characteristics see Table 3.