Table 2.

Szapiel score system.

Degree of alveolitis	Histopathologic features
0	No alveolitis
1	Thickening of the alveolar septum by a mononuclear cell infiltrate, with involvement limited to focal, pleural-based lesions occupying less than 20% of the lung and with good preservation of the alveolar architecture
2	A more widespread alveolitis involving 20%–50% of the lung, although still predominantly pleural based
3	A diffuse alveolitis involving >50% of the lung, with occasional consolidation of air spaces by the intra-alveolar mononuclear cells and some hemorrhagic areas within the interstitium and/or alveolus