Background: The diagnosis of tuberculosis has been based on the detection of tubercle bacilli by acid-fast stain of smear or cultures, and recently the serologic diagnosis of tuberculosis has been provided a means of sensitive and specific detection of Mycobacterium tuberculosis. We evaluated the utility of enzyme immunoassay using determiner Tuberculosis Glicolipids (TBGL) antibody kit (Kyowa Medex Co. Ltd, Japan) to detect anti-TBGL antibody for diagnosis of pulmonary tuberculosis.
Methods: Anti-TBGL antibody assay was performed to the sera from 44 patients with active pulmonary tuberculosis (17 patients with smear positive, 7 patients with only culture positive, 20 patients with clinically active tuberculosis) and 80 controls (30 healthy controls, 24 patients with non-tuberculous respiratory diseases, 26 patients with inactive tuberculosis). We compared the sensitivity and specificity of anti-TBGL antibody with culture and AFB stain.
Results: Anti-TBGL antibodies were detected in 16 of 17 (94%) smear positive patients, 4 of 7 patients with only culture positive and 16 of 20 (80%) smear negative patients who had been clinically diagnosed as active pulmonary tuberculosis. Nine (35%) out of 26 patients with inactive tuberculosis, one (4%) out of 24 patients with non-tuberculous respiratory diseases and no one of healthy control had a positive antibody response. Overall sensitivity, specificity of the anti-TBGL antibody assay were 82%, 88%, respectively and sensitivities and specificities of culture and AFB smear were 64%, 97% and 49%, 100%, respectively. Anti-TBGL antibody titers in patients with active tuberculosis were significantly higher than control group (P<0.05).
Conclusions: The anti-TBGL antibody assay was sensitive, rapid and convenient. This assay will be useful as a tool for the diagnosis of tuberculosis in combination with other conventional tests. (Korean J Clin Microbiol 2000;3(1):48-52)