Cytologic examination of bronchoalveolar lavage fluid from immunosuppressed patients.

Pulmonary infiltrates in immunocompromised patients frequently represent infections. This study was undertaken to evaluate cytologic examination of bronchoalveolar lavage samples and the value of different preparations and silver staining. Over 6 mo, 336 samples were collected from 155 immunosuppressed patients in whom both cytologic and microbiologic studies were performed. In 27 samples, the cytology, microbiology or both demonstrated the presence of infectious agents. In four cases, cytology identified neoplastic process. Cytology had a sensitivity of 34.6% for detection of infection, which increased to 42.9% when Cytomegalovirus was excluded. Cytology detected 6 of 15 cases of Aspergillus, including three cases not detected by microbiology and 3 of 4 cases of Pneumocystis, but did not identify any of the Cytomegalovirus cases. The type of preparations did not affect detection of the organism when present in cytologic samples and silver staining did not appear to have added value in examination of these samples.