Table 2.

Diagnostic criteria for methotrexate-induced lung injury[7,8]

Patients receiving methotrexate: Criteria to diagnose hypersensitivity pneumonia
Major criteria	Minor criteria
Hypersensitivity pneumonitis by histopathology without evidence of pathogenic organisms	Shortness of breath for <8 weeks
Radiographic evidence of diffuse pulmonary ground glass or consolidative opacities	Oxygen saturation ≤90% on room air at the time of initial evaluation
Blood cultures (if febrile) and initial sputum cultures (if sputum is produced) that are negative for pathogenic organisms	DLCO ≤70% of predicted age
	Non-productive cough
	Leukocyte count ≤15,000 cells/mm3

Methotrexate pneumonitis is characterized as: “definite” if major criteria 1 or 2 and major criterion 3 are in conjunction with three of the five minor criteria; “probable” methotrexate pneumonitis is present if significant criteria 2 and 3 plus two of the five minor criteria are present