Rapid diagnosis of smear-negative pulmonary tuberculosis via fibreoptic bronchoscopy: utility of polymerase chain reaction in bronchial aspirates as an adjunct to transbronchial biopsies.
Fibreoptic bronchoscopy was performed on 190 patients with chest radiographic lesions and negative sputum smears for acid-fast bacilli. Aside from obtaining transbronchial biopsies for histological examination, bronchial aspirate specimens were also tested for Mycobacterium tuberculosis complex DNA by a conventional polymerase chain reaction (PCR) technique. Of 177 transbronchial biopsies performed, a diagnosis was found in 64 cases [43 cases of tuberculosis (TB), 17 cases of lung carcinoma and four cases of other infective/inflammatory diseases] giving a diagnostic yield of 36.2%. PCR was positive in 105 of 108 finally diagnosed cases of TB and 22 of 82 non-TB cases. The sensitivity, specificity, positive predictive value and negative predictive value of PCR when applied to bronchial aspirate specimens for diagnosing smear-negative pulmonary TB were 97.2%, 73.2%, 82.7% and 95.2% respectively. Therefore, detection of M. tuberculosis complex DNA in bronchial aspirates by PCR might have an adjunctive place to transbronchial biopsies in the rapid diagnosis of smear-negative pulmonary tuberculosis.
Wong
C F
CF
Tuberculosis & Chest Unit, Grantham Hospital, Hong Kong.
Yew
W W
WW
Chan
C Y
CY
Au
L Y
LY
Cheung
S W
SW
Cheng
A F
AF
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001980:Bronchi / Q000382:microbiology*; D001999:Bronchoscopy; D017931:DNA Primers; D004269:DNA, Bacterial / Q000032:analysis*; D005260:Female; D005336:Fiber Optic Technology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013997:Time Factors; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis*
D017931:DNA Primers; D004269:DNA, Bacterial