Table 1. Definition of CMV pneumonia.

Classification
Proven	Positive CMV virus culture in bronchial washing fluid or the presence of intranuclear inclusion body or detection of CMV using immunohistochemical staining in a lung biopsy specimen
Probable	Presence of intranuclear inclusion body or detection of CMV using immunohistochemical staining in a cytologic specimen of bronchial washing fluid
Possible	Not classified as proven or probable
Indeterminate	Not classified as proven or probable and common respiratory virus other than CMV was isolated