COMPARISON OF QUANTITATIVE POLYMERASE CHAIN-REACTION, ACID-FAST BACILLI SMEAR, AND CULTURE RESULTS IN PATIENTS RECEIVING THERAPY FOR PULMONARY TUBERCULOSIS

Quantitative-competitive polymerase chain reaction (QPCR) was performe d on serial sputum samples from 22 consecutive cases of acid fast baci lli (AFB) smear-positive pulmonary tuberculosis. Of 94 specimens, 55, 72, and 83% were positive by culture, AFB smear, and QPCR, respectivel y. Of 52 culture-positive specimens, 6% were negative by PCR, and 13% were negative by AFB smear. Of 42 culture-negative specimens, AFB smea r and QPCR were positive in 55 and 61%, respectively. AFB smear and QP CR results were strongly correlated (r = 0.75, p < 0.001), but each co rrelated less strongly with culture (r = 0.54, p < 0.005 for smear and r = 0.52, p < 0.005 for QPCR). When patients were classified by micro biologic response, responders tended to have less DNA in their sputum and shorter time to a negative PCR result compared to nonresponders. T hese data do not suggest a great advantage of QPCR over AFB smear for predicting culture results in patients with pulmonary tuberculosis. (C ) 1997 Elsevier Science Inc.