Table 4.
Summary of SP-A and SP-D immunolocalization in normal peripheral and IPF lungs
| SP-A | SP-D | |
|---|---|---|
| Type II alveolar epithelial cells (in normal lungs) | + | + |
| Columnar ciliated cells | - | - |
| Regenerated type II alveolar epithelial cells | ++ | ++ |
| Fibrous parenchyma | - ~ + | - ~ ± |
| Mucus in honeycomb cysts | +++ | - ~ ± |
| Inside small vessels | - | - ~ + |
| Elastic fibers in the wall of blood vessels | + | - |
Immunostaining intensity: -, (none); ±, (more or less); +, (positive); ++, (more intense); and +++, (very intense). SP-A, surfactant protein A; SP-D, surfactant protein D; IPF, idiopathic pulmonary fibrosis.