QuantiFERON®-TB Gold Plus (Tuberculosis Test)

The QuantiFERON®-TB Gold Plus test is a blood test used to detect infection with Mycobacterium tuberculosis, the bacteria that causes tuberculosis (TB). This test measures the immune system’s response to TB-specific antigens, helping identify both latent (inactive) and active TB infections.

Unlike traditional skin tests, QuantiFERON-TB Gold Plus does not require a return visit and is not affected by prior BCG vaccination, making it a highly specific and convenient option for TB screening.

What the Test Covers

This test measures the release of interferon-gamma (IFN-γ) from immune cells in response to TB-specific proteins.

Why Consider This Test

• Screens for latent or active tuberculosis infection
• Not affected by BCG vaccination
• Requires only a single blood draw
• No need for return visit (unlike skin testing)
• Useful for employment, travel, or medical screening requirements

Reference Range

Results are reported as:

• Negative – No evidence of TB infection
• Positive – TB infection likely (latent or active)
• Indeterminate – Result unclear; repeat testing may be recommended

What Your Results May Mean

• Positive: Indicates TB infection; further evaluation is required to distinguish between latent and active disease
• Negative: TB infection unlikely at the time of testing
• Indeterminate: May occur due to immune factors or technical issues; repeat testing may be needed

This test is commonly used for routine TB screening, occupational health requirements, and pre-travel or immigration assessments, providing a reliable and convenient alternative to skin testing.