PNEUMOCYSTIS-CARINII IN BRONCHOALVEOLAR LAVAGE AND INDUCED SPUTUM - DETECTION WITH A NESTED POLYMERASE CHAIN-REACTION

To evaluate polymerase chain reaction (PCR) for detection of Pneumocys tis carinii, 117 bronchoalveolar lavage (BAL) specimens, from HIV-infe cted patients undergoing a diagnostic bronchoscopy, were processed and a nested PCR, followed by Southern blot and hybridization with a P-32 -labelled probe was performed. The sensitivity and specificity were 85 and 100% (34/40 and 77/77) respectively. A non-radioactive labelling system BluGENE was evaluated on all specimens, and found to be as effe ctive as P-32-labelling. To increase the speed and convenience of dete ction, a dot blot system was tested, but sensitivity dropped markedly with this system, A further 33 patients had both induced sputum and br onchoalveolar lavage performed and the induced sputum was analysed usi ng PCR and routine microbiological methods, The PCR sensitivity on ind uced sputum was equal to that of routine methods. At present the evalu ated PCR cannot replace routine microbiological methods for detection of Pneumocystis carinii, on either BAL fluid or induced sputum.