Clinical evaluation of the QuantiFERON-TB Gold test in patients with non-tuberculous mycobacterial disease.
OBJECTIVE
To evaluate the clinical usefulness of the QuantiFERON TB-2G (QFT-2G) test in patients with non-tuberculous mycobacterial (NTM) disease without a previous history of tuberculosis (TB).


METHODS
The study consisted of 214 patients with NTM disease who satisfied the diagnostic guidelines of the American Thoracic Society.


RESULTS
The causative microorganism was Mycobacterium avium in 83 patients, M. intracellulare in 80, M. kansasii in 33, M. marinum in 12, M. szulgai in 3, M. abscessus in 2 and M. chelonei in 1. The positive response rate of QFT-2G test result was 2% in 163 patients with M. avium-intracellulare complex (MAIC) disease, 52% in 33 with M. kansasii disease, 58% in 12 with M. marinum disease, 33% in 3 with M. szulgai disease, 0% in two with M. abscessus disease and 0% in one with M. chelonei disease. The positivity of the QFT-2G test was 52% in patients with NTM disease, thought to be because NTM possesses common M. tuberculosis-specific antigens.


CONCLUSIONS
Although QFT-2G may be a useful diagnostic method to differentiate TB from MAIC disease, there are several problems to be resolved before it can be used as a diagnostic method for NTM disease (M. kansasii disease), including the determination of the positive cut-off level for QFT-2G test.
Kobashi
Y
Y
Division of Respiratory Diseases, Department of Medicine, Kawasaki Medical School, Matsushima, Kurashiki, Japan. yoshihiro@med.kawasaki-m.ac.jp
Mouri
K
K
Yagi
S
S
Obase
Y
Y
Miyashita
N
N
Okimoto
N
N
Matsushima
T
T
Kageoka
T
T
Oka
M
M
D000368:Aged; D015415:Biomarkers / Q000097:blood; D003937:Diagnosis, Differential; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000097:blood*; D007564:Japan; D008297:Male; D008875:Middle Aged; D009165:Mycobacterium Infections, Nontuberculous / Q000175:diagnosis* / Q000382:microbiology; D015270:Mycobacterium avium-intracellulare Infection / Q000175:diagnosis / Q000382:microbiology; D009170:Nontuberculous Mycobacteria / Q000276:immunology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D014376:Tuberculosis / Q000175:diagnosis / Q000382:microbiology
D015415:Biomarkers; D011933:Reagent Kits, Diagnostic; D007371:Interferon-gamma