[Value of the immunochromatographic assay for detecting IgG antibodies against 38 kDa mycobacterial antigen in diagnosis of tuberculosis].
Despite of a fast development in the techniques of rapid identification of mycobacteria by molecular genetic techniques, serodiagnosis may be of special values as non-expensive, easy to perform method. Several serodiagnostic tests, principally those using immunoenzymatic (ELISA) methodology are available. The goal of our study was to evaluate one step coloured immunochromatographic assay detecting IgG antibodies against antigen 38 kDa (Rapid Test TB). Our material consisted of 278 serum samples--tuberculosis (n = 155), healthy (n = 36), sarcoidosis (n = 50), lung cancer (n = 25) mycobacterial infections other than tuberculosis (n = 12). Tuberculosis group consisted of new culture positive cases (n = 66), new culture negative cases (n = 23), chronic cases (n = 43) and extrapulmonary TB (n = 23). Specificity of 96% and sensitivity of 54% was obtained. In pulmonary TB sensitivity of 50% and in extrapulmonary TB of 74% was obtained. In chronic cases sensitivity of 70% and in new cases of 40% was received. Sensitivity of 44% in new culture positive cases and 30% in new culture negative cases was obtained. We conclude that immunochromatographic test may be a very useful tool improving tuberculosis diagnosis, especially in extrapulmonary tuberculosis. Strip test may be an interesting alternative as it is an extremely simple, rapid, and cheap technique.