Table 1.

Comparison of QuantiFERON-TB Gold and Tuberculin Skin Testing

How is the test performed?Laboratory measurement of interferon-gamma in whole bloodIntradermal injection of purified protein derivative and measurement of resulting induration
What does the test measure?In vitro release of interferon gamma after exposure to specific M. tuberculosis antigensIn vivo type intradermal hypersensitivity after injection of a mixture of mycobacterial antigens (not only M. tuberculosis)
Ability to detect tuberculous infectionYesYes
Ability to distinguish latent and active tuberculosisNoNo
False positive resultsYes, but less frequently than with the TST. False-positive results may occur with exposure to selected nontubercular mycobacteria, but not after BCG vaccination.Yes. False-positive results may occur after exposure to nontubercular mycobacteria or after BCG vaccination.
False negative resultsPossible among immunosuppressed individualsPossible among immunosuppressed individuals
Effect of BCG vaccinationNoneMay give a false-positive result after BCG vaccination
Need for patient to return for second visitNoYes, for reading of the skin reaction
Required infrastructureYes. Special equipment required in the laboratoryNo special infrastructure required. Easy to perform even in unsophisticated facilities
Subjectivity in reporting resultsNoYes, it may vary depending on training of individual
CostMore expensiveLess expensive
Time to obtain resultAt least 24 hours, but longer if run in batchesAt least 48 hours
Boosting an anamnestic response with successive testsNoYes
  • TST, tuberculin skin test; BCG, Bacillus Calmette-GuĂ©rin.