Objectives: To verify the value of cytomegalovirus (CMV) cultures of BAL fluid vs postmortem lung histopathology in detecting CMV pneumonia, and to correlate the BAL viral dose with the number of CMV inclusion bodies (CMV-IB) in the lung tissue of AIDS patients.
Design: Retrospective analysis of 434 BALs and 40 autopsies involving 307 AIDS patients; clinical follow-up lasted 10 months.
Patients and methods: The 40 patients who died within 20 days of undergoing BAL were divided on the basis of histopathologic findings into subjects with and without CMV-IB in the lung tissue. The relationship between the BAL viral dose and CMV lung infection was evaluated by counting the early antigen (CMV-EA) positive cells/200 µL of BAL and the number of CMV-IB/mm2 of lung tissue.
Results: The predictive value of BAL virus isolation for the diagnosis of CMV pneumonia was 61% for positive and 100% for negative results. The patients with the largest number of CMV-IB had CMV-EA counts from 2 to 840; in those with a moderate and small number, the CMV-EA counts were, respectively, from 11 to 700 and 2 to 300. Among the patients surviving up to 10 months after the BAL index sample, the frequency of recurrent extrapulmonary CMV abnormalities was 27% in those with positive and 7% in those with negative cultures.
Conclusions: BAL CMV cultures from AIDS patients have a very high negative and relatively low positive predictive value for CMV pneumonia. The presence and replication of CMV in the lung may lead to systemic dissemination as suggested by the higher probability of CMV extrapulmonary diseases. Viral titers do not seem to be related to the degree of lung damage.