Tuberculosis - Gamma Interferon - Quantiferon(T.B GOLD)

The QuantiFERON-TB Gold test is a blood-based interferon-gamma release assay that detects immune responses to Mycobacterium tuberculosis–specific antigens. It’s used primarily to identify latent TB infection and to screen people at risk (healthcare workers, contacts, or before immunosuppressive therapy). It helps guide further evaluation, but cannot by itself distinguish latent infection from active tuberculosis disease.

QuantiFERON‑TB Gold is a blood-based interferon‑gamma release assay (IGRA) that measures interferon‑gamma released by a person’s T cells after exposure to Mycobacterium tuberculosis–specific antigens. A single blood draw is incubated with antigens; results are reported as positive, negative, or indeterminate. It detects TB infection (latent or active but cannot distinguish them), is less affected by prior BCG vaccination, and may be unreliable in immunosuppressed patients.

A positive QuantiFERON indicates TB infection but cannot distinguish latent from active disease. Next steps: clinical assessment and chest X‑ray, sputum testing (microscopy/culture or NAAT) to exclude active TB. If active disease is ruled out, discuss latent TB treatment options (e.g., isoniazid or rifampin regimens), evaluate liver function and drug interactions, assess contacts, and consult a TB specialist or public health authority.

TB Gold (IGRA/QuantiFERON) costs vary by country and lab. Typical private-lab ranges: India ≈ ₹1,500–5,000; United States ≈ $50–200; UK/private clinics ≈ £40–150. Public health services often provide it free or it may be covered by insurance. Prices depend on the laboratory, location and billing—confirm the exact cost with your local testing center or insurer.

If you test positive for TB, clinicians will do further tests (chest X‑ray, sputum or molecular tests) to distinguish latent from active disease. Latent TB often gets preventive antibiotics for several months. Active TB requires multi‑drug therapy for at least six months, possible initial isolation, public‑health follow‑up with contact tracing, and regular monitoring for treatment response and side effects.

QuantiFERON‑TB Gold pricing varies by country, lab and insurance. Typical private costs: United States about $100–$200; United Kingdom roughly £40–£120 for NHS/private testing; India around ₹2,000–4,000 at commercial labs. Insurance or national health systems may reduce or cover fees. Check local laboratories or your insurer for exact, up‑to‑date pricing and any additional clinic or processing charges.