QuantiFERON-TB Gold Plus (QFT-Plus) is a simple blood test that aids in the detection of Mycobacterium tuberculosis, the bacteria which causes tuberculosis (TB).
You can improve your TB testing by switching to from the TB skin test (Tuberculin Skin Test, also known as the Mantoux or PPD test) to QFT-Plus (1):
QFT-Plus is an improved version of the industry-leading IGRA for TB detection, QuantiFERON-TB Gold. QFT-Plus uses the same principle, test procedures, and reliable technology that you trust, but is now optimized with innovative tuberculosis-specific antigens that elicit both CD8+ and CD4+ T cell responses – enabling a more accurate assessment of cell-mediated immune response to TB infection (2).
Unlike the TB skin test, QFT-Plus is not affected by the Bacille Calmette-Guérin (BCG) vaccination (1, 3, 4).
Table 1. QFT-Plus offers clear benefits over the tuberculin skin test (TST)
QFT-Plus (1, 3) | TST (3, 5) | |||
---|---|---|---|---|
Single visit assay? | Yes | Requires only one patient visit | No | Requires two patient visits |
High sensitivity? | Yes | 95% sensitivity – accurately identify TB-infected patients | No | 70% sensitivity – more missed diagnoses |
High specificity? (6) |
Yes | 98% specificity – less unnecessary follow-up and treatment | No | Variable; 59% in BCG-vaccinated populations – false positives result in unnecessary and costly follow-up |
Objective results? | Yes | Objective and controlled laboratory assay | No | Subjective measurement of skin induration |
Effective in BCG-vaccinated patients? | Yes | Unaffected by BCG vaccination | No | Results affected by BCG vaccination |
Most cost effective? (7–8) |
Yes | More cost effective than TST in multiple screening situations | No | High program costs due to second visits and false positives |
CD8+ T cells have been shown to play an important role in Mycobacterium tuberculosis immunity (9–11). QFT-Plus now measures the cell-mediated immune response to tuberculosis infection from both CD4+ and CD8+ T cells. The new TB1 tube primarily detects CD4+ responses, while TB2 is optimized for both CD4+ and CD8+ responses.
QuantiFERON technology has been the subject of over 1100 clinical and scientific studies, and maintains the highest accuracy of any test for TB infection. QFT-Plus provides the convenience of a single patient visit with electronic reporting, quantitative results and unparalleled accuracy.