Because bacteriologic study of sputum or bronchial aspirate specimens was not performed in 4 patients (8 specimens), a total of 331 patients (392 bronchial aspirate specimens) were included in this study (Table 1). Bacteriologic study of sputum and bronchial aspirate specimens was performed in 302 and 321 patients, respectively. Bronchial musoca or lung biopsies were performed in 116 patients. Of the 331 subjects, 43 patients were confirmed as having pulmonary tuberculosis either bacteriologically, histologically, or both, and 9 patients had clinical tuberculosis. Because the CA tests were performed after all 392 samples were collected, there were no room for the attending physicians to be biased by the CA results at the time of decision whether or not the patients had pulmonary tuberculosis clinically.
Direct smear-positive, culture- or biopsy-confirmed, and CA-positive results were obtained in 16 subjects (16 specimens), 43 subjects (49 specimens), and 29 subjects (32 specimens), respectively (Table 2). Canadian health&care mall read more Excluding the 3 subjects who had a positive AFB smear but negative culture or histology results for M tuberculosis. of the 13 smear-positive tuberculosis subjects, 7 subjects had positive findings only in bronchial aspirates, 3 subjects had positive findings only in sputum, and the remaining 3 subjects had positive findings in both sputum and bronchial aspirates.
For sputum or bronchial aspirate AFB smears, sensitivity was 27% (13 of 49 smears) and specificity was 99% (340 of 343 smears). The sensitivity and specificity of CA tests were 53% (26 of 49 smears) and 98% (337 of 343 smears), respectively. The CA test was more sensitive than the Ziehl-Neelson AFB smear for the diagnosis of pulmonary tuberculosis (53% vs 27%, p < 0.05). In AFB smear-positive patients, the sensitivity, specificity, PPV, and NPV of CA tests for the diagnosis of tuberculosis were 92%, 67%, 92%, and 67%, respectively.
Table 1—Clinical Characteristics of the 335 Patients Studied
|Age, yr||56 ± 16*|
|Male/female sex, No.||217/118|
|Positive/negative/unknown history of tuberculosis, No.||80/245/10|
|Bronchoscopies performed, No. (range)||400 (1-8/person)|
|Interstitial lung disease||27|
|Airway stenosis (for intervention)||14|
Table 2—Performance of CA in Bronchial Aspirates of AFB Smear-Positive and Smear-Negative Patients
|CA ( +)||CA (-)||CA (+)||CA(-)|
|Smear positive (n = 16)||12||1||1||2||92||67||92||67|
|Smear negative (n = 37)||14||22||5||335||38||99||74||94|