Diagnostics for Active Pulmonary and Extrapulmonary ...

Diagnostics for Active Pulmonary and Extrapulmonary Tuberculosis

 • Sputum - Send expectorated or induced sputum for AFB smear and culture x3 ≥8hrs apart (get NAAT/PCR on one of the specimens); smear may be (-) if burden is low: ~20% smear negative (HIV-), ~60% smear negative (HIV+)

 • Bronchi - Send brushings, washings, BAL, sputum for AFB smear, NAAT/PCR and culture; +/- transbronchial biopsy. Obtain post-bronch induced sputum to increase yield. 

 • Ascites or pleural fluid - Adenosine Deaminase (ADA): if >39 units/L → high sens/spec; Free IFN-gamma (if elevated, high sens/spec); AFB smear, NAAT/PCR, and culture (poor sensitivity, helpful if positive)

 • CSF - At least 3 large vol (10-15cc) serial LPs if possible (Increases dx yield). Cell counts w/ ↓ glucose, ↑ protein, lymphocyte predominance; elev ADA useful adjunct. Send smear, Cx, and NAAT

 • Wound/Tissue - AFB-positive staining and caseating granulomas; if cytopenic, consider bone marrow biopsy

 • Urine - Classically sterile pyuria; send first AM void (large vol -50cc) for culture x 3 days to improve yield

 • Blood - Must send mycobacterial cultures for AFB (isolators)

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MGH White Book Manual
Account created for the MGH Internal Medicine Housestaff Manual "White Book" - https://stk10.github.io/MGH-Docs/WhiteBook-2019-2020.pdf
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