[Serodiagnosis with trehalose-6,6'-dimycolate of pulmonary tuberculosis]

Enzyme-linked immunosorbent assay (ELISA) was used to examine serum antibody levels of mycobacterial antigen in 92 patients with active tuberculosis, 36 with cured tuberculosis, 45 with nontuberculous mycobacteriosis, and as 31 with other diseases. Glycolipid fraction containing mainly cord factor (trehalose-6,6'-mycolate) from Mycobacterium tuberculosis H37Rv were used as ELISA antigen. Overall positive rates of the ELISA tests in the patients with active pulmonary tuberculosis, those with nontuberculous mycobacteriosis, and those with other diseases were 67.4%, 75.6%, and 6.5%, respectively. Patients with tuberculosis and those with nontuberculous mycobacteriosis differed from the control group (p < 0.0001). Higher positive rates were correlated with bacterial loads (smear-positive vs smear-negative, p < 0.01) and with chest roenrgenographic findings (far advanced or other cavitary vs noncavitary, p < 0.01). Because 18 of 36 smear-negative patients (50%) had positive results, we believe that the ELISA test with this antigen can be useful for diagnosis of M. tuberculosis, especially in patients with smear-negative.