TABLE 3.

Mean analytical data showing QFT-IT performance

Assay antigenIFN-γ test resulta (IU/ml)
Positiveb (n = 1)Negativec (n = 63)Indeterminated (n = 16)
Control1.30.5 ± 2.0 [0.1]0.1 ± 0.05 [0.1]
ESAT-6/CFP-10/TB7.72.70.4 ± 1.4 [0.1]0.1 ± 0.07 [0.1]
PHAe57.636.4 ± 32.4 [25.5]0.2 ± 0.2 [0.1]
  • a Data are expressed as means ± standard deviations [median]. n, number of patients.

  • b IFN-γ in TB antigen-stimulated sample ≥ 0.35 IU/ml with valid positive control represented a positive result.

  • c IFN-γ in TB antigen-stimulated sample < 0.35 IU/ml with positive control ≥ 0.5 IU/ml represented a negative result.

  • d IFN-γ in TB antigen-stimulated sample < 0.35 IU/ml with positive control < 0.5 IU/ml represented an indeterminate result.

  • e PHA, phytohemagglutinin.