Issues with Quantiferon Gold Tuberculosis Testing

The University of Iowa Hospitals and Clinics Department of Pathology has become aware that the referral laboratory for QuantiFERON-TB Gold In-Tube testing (Mayo Medical Laboratories) has revised months of positive tests for Mycobacterium tuberculosis to indicate the possibility of false positive testing generated by a possible contamination event at the manufacturer.

The Assay
QuantiFERON-TB Gold In-Tube (QFT-GIT) is a 3-tube test that measures T-cell production of the cytokine interferon gamma in response to antigens from Mycobacterium tuberculosis (MTB) in comparison to positive and negative control tubes.  As there are only recombinant MTB antigens in the first tube, a positive result is interpreted as infection by MTB.  QFT-GIT therefore may be useful in the diagnosis of latent MTB infection, even in those who have been vaccinated with BCG and have a positive tuberculin skin test (TST).

Recall Scope


For further questions about laboratory testing, please contact Bradley Ford (Associate Director, Clinical Microbiology) 6-2990, J. Stacey Klutts (Director, Clinical Microbiology, University of Iowa Hospitals and Clinics & VA Health Care System) or Matthew Krasowski (Clinical Chemistry and Serology) 4-9380.  For clinical questions, please contact Drs. Daniel Diekema (Infectious Disease) 4-5626 or Douglas Hornick (Pulmonary, Critical Care and Occupational Medicine) 6-8266.