EVALUATION OF 2 COMMERCIAL AMPLIFICATION ASSAYS FOR DETECTION OF MYCOBACTERIUM-TUBERCULOSIS COMPLEX IN RESPIRATORY SPECIMENS

To evaluate the usefulness of two standardized commercially available amplification assays for the detection of Mycobacterium tuberculosis: Amplicor(R) test (Roche) and MTD-Amplified direct test (Gen-Probe) a t otal of 281 respiratory specimens from 198 patients with symptoms of p ulmonary diseases were examined and compared with conventional methods , Fifty-seven specimens were positive and 218 negative by both amplifi cation assays. Three specimens were reactive by Amplicor(R) only, and three by MTD only, In comparison with culture, the sensitivity, specif icity, positive predictive value and negative predictive value were 96 .0, 94.8, 80.0, and 99.1%, respectively, for the Amplicor(R) test; the corresponding values were 94.0, 94.4, 78.3, and 98.6%, respectively, for the MTD, However, when 28 specimens from 14 patients on antituberc ulous therapy were excluded the improvement in PPV and specificity of both assays was obtained, In conclusion, both commercially available a mplification tests are almost equally sensitive and specific and are s uitable for the implementation in daily routine work in the specialize d clinical laboratories.