DIAGNOSIS OF CYTOMEGALOVIRUS IN BRONCHOALVEOLAR LAVAGE BY POLYMERASE CHAIN-REACTION, IN COMPARISON WITH VIRUS ISOLATION AND DETECTION OF VIRAL-ANTIGEN

Bronchoalveolar lavage (BAL) products from 52 immunocompromised patien ts with symptoms of pulmonary infection was examined for cytomegalovir us (CMV) by virus isolation, polymerase chain reaction (PCR) and detec tion of CMV antigen by immunofluorescence or immunoperoxidase staining after short-term incubation in tissue culture and directly in BAL cel ls. We found that PCR detected all cases positive by virus isolation ( 15/52 samples) and the result was obtained within 5 h. PCR detected mo re cases of CMV than did virus isolation (22/52 samples). Positive PCR and negative virus isolation were consistent with probable CMV infect ion in 3/7 patients when other clinical and laboratory parameters of C MV infection were considered. The negative predictive value of PCR was high; none of 30 patients negative by PCR developed CMV pneumonia wit hin the subsequent 2 months. Detection of CMV antigen after short-term incubation was rapid enough to be used in clinical practice, specific (100%) and with a sensitivity of 60%. Demonstration of CMV antigen in alveolar cells was highly specific (100%) but had too low a sensitivi ty (26.7%) to be used as the only rapid method. Our conclusion is that a combination of PCR and detection of CMV antigen after short-term in cubation and directly in alveolar cells is optimal for rapid identific ation of CMV.