6
Diagnosis
➤ The panel suggests flexible bronchoscopic sampling, rather than
no bronchoscopic sampling, in adults with suspected pulmonary
TB from whom a respiratory sample cannot be obtained via
induced sputum (C-VL).
Remarks: In the committee members' clinical practices, bronchoalveolar lavage (BAL)
plus brushings alone are performed for most patients. However, for patients in whom a
rapid diagnosis is essential, transbronchial biopsy is also performed.
➤ The panel suggests that postbronchoscopy sputum specimens
be collected from all adults with suspected pulmonary TB who
undergo bronchoscopy (C-L).
Remarks: Postbronchoscopy sputum specimens are used to perform AFB smear
microscopy and mycobacterial cultures.
➤ The panel suggests flexible bronchoscopic sampling, rather than
no bronchoscopic sampling, in adults with suspected miliary TB
and no alternative lesions that are accessible for sampling whose
induced sputum is AFB smear microscopy negative or from whom a
respiratory sample cannot be obtained via induced sputum (C-VL).
Remarks: Bronchoscopic sampling in patients with suspected miliary TB should
include bronchial brushings and/or transbronchial biopsy, as the yield from washings
is substantially less and the yield from BAL unknown. For patients in whom it is
important to provide a rapid presumptive diagnosis of tuberculosis (ie, those who are
too sick to wait for culture results), transbronchial biopsies are both necessary and
appropriate.
➤ The panel suggests that cell counts and chemistries be
performed on amenable fluid specimens collected from sites of
suspected extrapulmonary TB (C-VL).
Remarks: Specimens that are amenable to cell counts and chemistries include pleural,
cerebrospinal, ascitic, and joint fluids.
➤ The panel suggests that adenosine deaminase levels be
measured, rather than not measured, on fluid collected from
patients with suspected pleural TB, TB meningitis, peritoneal TB,
or pericardial TB (C-L).
➤ The panel suggests that free IFN-γ levels be measured, rather
than not measured, on fluid collected from patients with
suspected pleural TB or peritoneal TB (C-L).
➤ The panel suggests that AFB smear microscopy be performed,
rather than not performed, on specimens collected from sites of
suspected extrapulmonary TB (C-VL).
Remarks: A positive result can be used as evidence of extrapulmonary TB and guide
decision making because false-positive results are unlikely. However, a negative result
may not be used to exclude TB because false-negative results are exceedingly common.
