Utility of Testing Bronchoalveolar Lavage Fluid for Cryptococcal Ribosomal DNA

Bronchoalveolar lavage (BAL) specimens from 88 patients (33 infected with human immunodeficiency virus [HIV], 45 non-HIV immunosuppressed patients and 10 immunocompetent patients with primary pulmonary disease) were analysed for the presence of Cryptococcus neoformans. Staining, culture and an antigen testing were performed, and C. neoformans ribosomal DNA (rDNA) detected using the polymerase chain reaction (PCR). C. neoformans was detected, by staining and culture, in BAL specimens from two HIV-infected patients with pulmonary cryptococcosis, and the antigen test and rDNA assay were also positive in these samples. C. neoformans rDNA was detected by PCR in a non-HIV immunocompromised patient with Pneumocystis pneumonia, whose staining, culture and antigen tests were negative. The antigen test was positive for an immunocompetent patient with sarcoidosis, while staining, culture and the PCR assay were negative. These results do not support routine testing of BAL specimens for C. neoformans rDNA.