Evaluation of a commercially available serologic assay for antibodies against tuberculosis-associated glycolipid antigen.
A commercially available enzyme immunoassay developed to detect antibodies to a tuberculosis-associated glycolipid antigen was evaluated for serologic diagnosis of tuberculosis. This was a multicenter study comparing the assay with other methods in 78 patients with active pulmonary tuberculosis and in 54 controls with non-tuberculous lung diseases. Sensitivities were highest for sputum culture (91.0%), followed by immunoassay (79.5%), nucleic acid amplification (77.3%), and finally acid-fast staining of sputum smear (60.3%). Immunoassay and amplification, both rapid methods, had similarly high sensitivity in smear-positive subjects (89.4 and 88.9%, respectively); in smear-negative subjects these two techniques showed low sensitivity (64.5 and 60.0%, respectively). Concordance between the two methods was relatively low (72.0%). With regard to specificity, seven out of ten patients with old tuberculosis had positive result by immunoassay (30% specificity). In the control group, 10 out of 54 patients had positive immunoassay result (72.2% specificity), with notably limited specificity in the elderly. The tuberculous glycolipid assay is a rapid method sufficiently sensitive for detection of tuberculosis infection, even in smear-negative patients.
Iinuma
Yoshitsugu
Y
Department of Clinical Laboratory, Nagoya University Hospital, Nagoya-city, Japan. yiinuma@med.nagoya-u.ac.jp
Senda
Kazuyoshi
K
Takakura
Shunji
S
Ichiyama
Satoshi
S
Tano
Masao
M
Abe
Tomoji
T
Yamamoto
Tomoko
T
Nakashima
Kazumitsu
K
Baba
Hisashi
H
Hasegawa
Yoshinori
Y
Shimokata
Kaoru
K
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology; D016022:Case-Control Studies; D003951:Diagnostic Errors; D006017:Glycolipids / Q000276:immunology; D006801:Humans; D007118:Immunoassay / Q000592:standards; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D011933:Reagent Kits, Diagnostic / Q000592:standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014397:Tuberculosis, Pulmonary / Q000097:blood / Q000175:diagnosis*
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D006017:Glycolipids; D011933:Reagent Kits, Diagnostic