Combined bronchoalveolar lavage and polymerase chain reaction in the diagnosis of pulmonary tuberculosis in smear-negative patients.
METHODS
The polymerase chain reaction (PCR) may be sensitive and specific for the diagnosis of tuberculosis, but most reports are of studies conducted in well-controlled laboratories. A study to evaluate the clinical value of bronchoalveolar lavage (BAL) combined with PCR was necessary.


OBJECTIVE
One hundred and thirty one patients were recruited into the study from March 1994 to February 1997.


METHODS
Patients with a positive acid-fast stain on sputum smear were recruited into group A as positive controls, patients with lung cancer and a negative acid-fast stain on sputum smear were put into group B as negative controls, and patients who had clinical symptoms of pulmonary TB without sputum or with negative smear results were the investigating group. PCR was performed on the sputum samples from group A and B patients and on the BAL fluid from those in group C.


RESULTS
The sensitivity of PCR was 96% in group A, and the specificity was 100% in group B. The sensitivity of PCR in the BAL fluid from the group C patients was 36% and the specificity was 96%; the positive predictive value was 94% and the negative predictive value was 45%.


CONCLUSIONS
BAL plus PCR is useful in the rapid diagnosis of pulmonary TB in non-productive or smear-negative patients.
Chen
N H
NH
Department of Pulmonary and Critical Care Medicine, Chang Gung Memorial Hospital, Taipei, Taiwan. ninghung@yahoo.com.tw
Liu
Y C
YC
Tsao
T C Y
TC
Wu
T L
TL
Hsieh
M J
MJ
Chuang
M L
ML
Huang
C C
CC
Kuo
A J
AJ
Chen
M C
MC
Yang
C T
CT
D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology*; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000382:microbiology