[Diagnostic role of fiberoptic bronchoscopy for mycobacterial diseases--serological diagnosis].

Detection of IgG antibodies against purified cord factor (trehalose-6, 6'-dimycolate) prepared from Mycobacterium tuberculosis H37Rv was carried out by the method of enzyme-linked immunosorbent assay (ELISA) and its diagnostic usefulness was also evaluated in this study. Sera from 65 patients with active pulmonary tuberculosis, 58 patients with inactive pulmonary tuberculosis, 36 patients with diseases other than tuberculosis and 66 healthy adults were examined. Patients with active pulmonary tuberculosis showed significantly higher titers of IgG antibodies against cord factor than other groups (p < 0.001). Patients with inactive pulmonary tuberculosis also showed significantly higher titers of IgG antibodies against cord factor than patients with diseases other than tuberculosis and healthy adults (p < 0.001). An antibody titers of greater than 0.29 were established as a positive ELISA test. For patients with active pulmonary tuberculosis, the ELISA had a sensitivity of 85% and a specificity of 96%. From these results, it is concluded that the detection of IgG antibodies against cord factor is useful for the serodiagnosis of active or inactive pulmonary tuberculosis.