Quantiferon-TB Gold Plus by CLIA: Do we need a higher cut-off?

Head-to-head comparison of qualitative and quantitative QFT-Plus assay results by enzyme-linked immunoassay (ELISA) and chemiluminescence immunoassay (CLIA) was performed on 419 QFT-Plus blood samples.
The study was conducted at the Unit of Microbiology of the S. Orsola-Malpighi University Hospital in Bologna (Italy).
Database reports Nil, TB1, TB2, Mitogen quantitative values and qualitative results of QFT-Plus both by ELISA and CLIA, assays date and sample storage time.