Background: Diagnosis of tuberculosis is more complicated because of low sensitivity and time-consuming procedures of the conventional diagnostic methods as well as nonspecific clinical features. Recently the serologic diagnosis of tuberculosis has been reported as one of rapid sensitive and specific methods. We evaluated the ability of a rapid ICT Tuberculosis assay (AMRAD/ICT Diagnostics, Sydney, Australia) to detect pulmonary tuberculosis.

Methods: ICT Tuberculosis assay was performed to the sera from 50 patients with pulmonary tuberculosis (24 patients with smear positive, 26 patients with smear negative) and 105 controls (48 patients without tuberculosis, 57 healthy controls).

Results: Antibodies were detected in 22 of 24 (92%) smear positive patients and 22 of 26 (85%) smear negative patients who had been clinically diagnosed as having active pulmonary tuberculosis. Two (4.2%) out of 48 patients without tuberculosis and 1 (1.8%) out of 57 healthy controls had a positive antibody response. The overall sensitivity, specificity, and positive and negative predictive value of the ICT Tuberculosis assay were 88%, 97%, 94%, and 94%, respectively.

Conclusions: The ICT Tuberculosis assay was not only sensitive and specific but also rapid and simple. This assay will be useful as a diagnostic method of pulmonary tuberculosis in combination with sputum smear and X-ray. (Korean J Clin Microbiol 1999;2:167-171)