ROLE OF ANTIGEN-SPECIFIC CIRCULATING IMMUNE-COMPLEXES IN DIAGNOSIS OFTUBERCULOSIS

SETTING: Tuberculosis is a public health problem worldwide. Early accu rate diagnosis in patients with active disease is essential to reduce morbidity and mortality. Conventional methods for detection of Mycobac terium tuberculosis have given disappointing results. OBJECTIVE: TO ev aluate the utility of detection of M. tuberculosis antigen in circulat ing immune complexes (CIC) for the diagnosis of tuberculosis. RESULTS: In total, 22 out of 84 cases were positive for culture on Lowenstein Jensen medium; 76.5% (n = 65) of the clinically diagnosed patients (in cluding 20 culture-positive cases) were found to be positive by ELISA. The difference in mean absorbance values of ELISA in cases of tubercu losis was significantly higher than in controls. The sensitivity of EL ISA was 90.9% and the specificity was 93.04%. CONCLUSION: Detection of M. tuberculosis antigen in CIC by ELISA has potential as a useful dia gnostic tool for the rapid diagnosis of tuberculosis, especially extra pulmonary forms where results of conventional methods of diagnosis are disappointing.METHOD: Eighty-four clinically diagnosed cases of mainl y extra-pulmonary tuberculosis, 85 patients with diseases other than t uberculosis and 30 healthy controls, were evaluated for the presence o f antigen of M. tuberculosis in CIC in serum using sandwich enzyme lin ked immunosorbent assay (ELISA).