Figure 2

Characteristic tissue niche in chronic airway diseases. Panel (a) shows a histological section from a patient with IPF, characterized by a fibroblastic foci (outlined area) located below the epithelial layer (arrows). The fibroblastic foci is an area rich in ECM but with only few cells with a stretched morphology, located in parallel to the alveolar septa cells. Panel (b) shows a histological section from a patient with asthma, characterized by thickening of the basement membrane (arrows), shedding of the epithelial layer (closed arrowheads) and formation of peribronchial fibrosis (open arrowheads). Panel (c) shows a partially obliterated bronchiole (outlined area) in a patient with OB after lung transplantation. OB is histologically identified as ECM plugs with few fibroblasts. Original magnification 20×. Scale bar = 100 μm.