title: Clinical usefulness of QuantiFERON TB-2G test for the early diagnosis of pulmonary Mycobacterium kansasii disease.
abstract: We encountered five cases of pulmonary Mycobacterium kansasii (MK) disease for which the QuantiFERON-TB Gold (QFT-2G) test was useful as a supportive diagnostic method. Because none of these patients could expectorate sputum, we ultimately confirmed the clinical diagnosis of pulmonary MK disease using 6- to 8-week cultures of bronchoscopic specimens (bronchoalveolar lavage fluid) according to the guidelines for nontuberculous mycobacterial disease due to American Thoracic Society/Infectious Diseases Society of America. The tuberculin skin test showed positive responses in all cases, and the QFT-2G test showed positive response for ESAT-6 only or CFP-10 only antigens. After it was proved that the result of Mycobacterium tuberculosis (MTB)-nucleic acid amplification was negative and the result of the QFT-2G test was positive, we started treatment (isoniazid, rifampicin and ethambutol) for suspected pulmonary MK disease based on clinical findings in all cases. The clinical effect was good and the interferon-gamma response to MTB-specific antigen decreased with treatment for pulmonary MK disease. The QFT-2G test may be useful as a rapid supportive diagnostic method for pulmonary infection due to MK possessing the same MTB-specific antigen.
authors.affiliation: Division of Respiratory Diseases, Department of Medicine, Kawasaki Medical School, Kurashiki 701-0192, Japan. yoshihiro@med.kawasaki-m.ac.jp
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kobashi
authors.forename: Keiji
authors.initials: K
authors.lastname: Mouri
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Miyashita
authors.forename: Mikio
authors.initials: M
authors.lastname: Oka
mesh_terms: D000368:Aged; D000942:Antigens, Bacterial / Q000032:analysis; D001426:Bacterial Proteins / Q000032:analysis; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009165:Mycobacterium Infections, Nontuberculous / Q000175:diagnosis* / Q000382:microbiology; D019909:Mycobacterium kansasii / Q000302:isolation & purification*; D014374:Tuberculin Test; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis*
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C117940:CFP-10 protein, Mycobacterium tuberculosis; C093276:ESAT-6 protein, Mycobacterium tuberculosis; D007371:Interferon-gamma