Q: 44 year old male, recently migrated from a developing country is admitted to ICU with 'sepsis kind of picture', hypotension, fever, cough and low grade fever. CXR showed cavitary lesion at right upper lobe. Interferon-gamma release assays (IGRAs) is ordered by an on-call resident, which is reported negative now. Negative IGRAs rule out the active tuberculosis (TB).
IGRAs is still a controversial test and has raised many eyebrows of experts as it has 'issues' with reproducibility in labs, and require many perfect technical parameters. IGRAs can be a good diagnostic tools for latent tuberculosis infection (LTBI). But, it cannot distinguish between latent infection and active tuberculosis (TB).
A positive IGRA result may not necessarily indicate active TB, and a negative IGRA result may not rule out active TB.
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