[Polymerase chain reaction assay for the diagnosis of pneumocystis carinii and cytomegalovirus pneumonia].

We evaluated the utility of the polymerase chain reaction (PCR) method in detecting Pneumocystis carinii (PC) and cytomegalovirus (CMV) in bronchoalveolar lavage (BAL) specimens from patients suspected of having opportunistic infection of the lung. We evaluated BAL samples obtained from 41 immunosuppressed patients who had signs and symptoms of acute lower respiratory tract infection. In addition, we studied 16 immunocompetent patients. PC-DNA was detected in 19 cases and CMV-DNA was detected in three cases, in the immunosuppressed group. The diagnosis could not be established by conventional techniques in nine of these positive cases. PC-DNA was detected in all cases in which PC organisms had been demonstrated by silver or Giemsa staining. Neither PC nor CMV-DNA was detected in immunocompetent patients. We conclude that the PCR assay has greater sensitivity for the detection of PC and CMV-DNA in BAL specimens than conventional approaches and therefore enhances our diagnostic capability for PC and CMV pneumonia.