Is the QuantiFERON-TB blood assay a good replacement for the tuberculin skin test in tuberculosis screening? a pilot study at Berkshire Medical Center.
The QuantiFERON-TB Gold In-Tube method (QFT-GIT; Cellestis, Carnegie, Australia) is a recently US Food and Drug Administration-approved interferon-gamma release assay (IGRA) for the detection of tuberculosis infection, which has been screened for by the tuberculin skin test (TST) for nearly a century. We report a pilot study comparing the QFT-GIT and TST results for screening health care workers (HCWs) at Berkshire Medical Center (BMC; Pittsfield, MA), the second hospital in Massachusetts to use QFT-GIT. For the study, 40 BMC HCWs, 20 TST+ and 20 TST-, were screened with the QFT-GIT test. All 20 TST- subjects were also QFT-GIT-, while only 10 of 20 TST+ subjects were QFT-GIT+. The overall agreement between the QFT-GIT and TST results was 75% (kappa = 0.5; 95% confidence interval, 0.268-0.732). The suboptimal agreement was partially due to a higher specificity of QFT-GIT. Confounding factors (eg, bacille Calmette-Guérin vaccination status and birthplace) are discussed, and literature regarding IGRAs and their comparison with TST is reviewed.
Department of Pathology and Laboratory Medicine, Berkshire Medical Center, Pittsfield, MA 01201,USA.
Xiangrong
X
Zhao
Damir
D
Mazlagic
Ethan A
EA
Flynn
Helda
H
Hernandez
Charles L
CL
Abbott
D003430:Cross-Sectional Studies; D006403:Hematologic Tests / Q000379:methods*; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014374:Tuberculin Test; D014376:Tuberculosis / Q000097:blood* / Q000175:diagnosis*