Table 1.

Fibrotic lung remodeling according to the Ashcroft score [22]

Grade of fibrosis	Histological changes
0	Normal lung
1	Minimal fibrous thickening of alveolar/bronchial walls
2	Intermediary stage between 1 and 3
3	Moderate thickening of walls without obvious damage to the lung architecture
4	Intermediary stage between 3 and 5
5	Increased fibrosis with definite damage to lung structure and formation of fibrous bands or small fibrous masses
6	Intermediary stage between 5 and 7
7	Severe distortion of structure and large fibrous areas; honeycombing lung is placed in this category
8	Total fibrous obliteration of the field