QuantiFERON-TB Gold Plus (QFT-Plus)

QFT-Plus is an IFNγ release assay, commonly known as an IGRA, and measures the cell-mediated immune response to specific TB antigens in whole blood. Patients may be tested in a single patient visit, with objective results.

Additional clinical value comes from the exclusive TB-specific antigens that elicit CD4⁺ and CD8⁺ T-cell responses. This new test format, combined with improvements in tuberculosis test formulation and manufacturing, means more robust and reliable assay performance.

QuantiFERON is a powerful Premolecular diagnostic technology that delivers results with high sensitivity, enabling the detection of M. tuberculosis infection even in early or latent stages. The QFT-Plus test employs a peptide cocktail simulating ESAT-6 and CFP-10 proteins to stimulate cells in heparinized whole blood. Detection of IFN-γ by ELISA is used to identify in vitro responses to these peptide antigens, which are associated with M. tuberculosis infection. Premolecular Diagnostics that employ QuantiFERON technology, like QFT-Plus, are able to detect infection at an earlier stage than is possible with DNA- and RNA-based molecular diagnostics.

1. Collect whole blood in a standard blood collection tube, or specialized QFT-Plus Blood Collection Tubes.
2. Incubate for 16 to 24 hours at 37°C.
3. Detect released IFNγ in harvested plasma by ELISA.
4. Analyze results using QFT-Plus Analysis Software.

QFT-Plus has 4 blood collection tubes: Nil, TB1, TB2, and Mitogen. Collect 1 ml of whole blood into each tube.

• People taking certain medications (e.g., TNF alpha inhibitors)
• Patients with weakened immune systems
• Elderly patients