What should you know about IGRA and QuantiFERON Gold?

A positive result suggests that your immune system has encountered tuberculosis bacteria. It does not by itself show whether the infection is active, where it is located, or whether you can pass it to another person. A negative result makes infection less likely, but recent exposure, a weakened immune system, or testing too soon can affect interpretation. An indeterminate result means the laboratory could not provide a dependable answer and a repeat test or another method may be discussed.

Your clinician combines the result with symptoms, exposure history, previous treatment, immune health, and examination findings. A chest X-ray or other assessment may be needed to distinguish inactive infection from active tuberculosis.

Arrange a follow-up appointment so the result is interpreted in context. Tell the clinician about close contact with someone who had tuberculosis, previous tuberculosis treatment, recent travel or residence in an affected area, and medicines that suppress immunity. The blood draw usually needs one visit, and fasting is not generally the focus of this test unless other blood tests are planned. Do not start or stop tuberculosis medicine without clinical advice.

If the result is positive, follow the recommended assessment plan even if you feel well. Treatment may be considered to reduce the chance of inactive infection becoming active disease.

Seek prompt medical care for a persistent cough, coughing blood, chest pain, fever, night sweats, unexplained weight loss, or marked tiredness, especially after a known tuberculosis exposure. Seek urgent help for severe breathing difficulty, confusion, or coughing a large amount of blood. These symptoms need assessment because active tuberculosis and other illnesses can require timely care.

Ask whether your result is positive, negative, or indeterminate; whether you need a chest X-ray; whether symptoms or exposure change the interpretation; and whether treatment or repeat testing is appropriate.