High QuantiFERON-TB (interferon-gamma release assay): what it means
A QuantiFERON-TB (interferon-gamma release assay) result above the normal range is considered high. Here is what a raised QuantiFERON-TB (interferon-gamma release assay) can point to, and when it is worth discussing with a doctor.
Reference range: Reported as negative, positive or indeterminate; negative is the expected result — a positive indicates infection with the TB bacterium (usually latent, dormant TB), and does not by itself distinguish latent from active disease, which needs a chest X-ray and clinical assessment
Understand your full resultWhat a high QuantiFERON-TB (interferon-gamma release assay) can mean
- A positive result — the immune system has met the TB bacterium; you carry the infection.
- Latent TB infection — the commonest meaning; dormant bacteria, no symptoms, not contagious, but treatable to prevent future active disease.
- Active TB disease — possible if there are symptoms; needs a chest X-ray and further tests to confirm, as the blood test alone cannot distinguish it.
- An indeterminate result — the test could not be interpreted (sometimes with a weak immune system); usually repeated.
When to discuss with a doctor
This TB blood test is used to detect latent TB infection — commonly when screening people at higher risk (close contacts of someone with TB, people from higher-incidence regions, healthcare workers) and, importantly, before starting treatments that suppress the immune system, which can reactivate dormant TB. A positive result usually means latent, dormant infection and prompts a chest X-ray and clinical review to rule out active disease; if latent, a course of treatment may be offered to prevent it becoming active later. A positive test with symptoms such as a persistent cough, fevers, night sweats or weight loss needs prompt assessment for active TB, which is contagious and treatable. Mediora.AI shows the TB test result alongside relevant markers so it is read in context; interpreting a positive result and deciding on treatment belong with your doctor.
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One value is a snapshot. Upload the full test to see every marker explained together.
Upload your test - freeMediora.AI is informational - interpretation, not a diagnosis. A single out-of-range value is common and often benign; always discuss decisions with your doctor.