Clinical Usefulness of Various Methods for the Diagnosis of Tuberculosis

Ha, Gyoung Yim; Lee, Young Hyun

Abstract

BACKGROUND: In the diagnosis of tuberculosis, methods that have high sensitivity and specificity such as polymerase chain reaction and serologic test of tuberculosis have been introduced recently. Thus, we performed AFB stain, culture, PCR-ybridization and serologic test of tuberculosis to determine the clinical usefulness of each method in patients who were diagnosed as having pulmonary and extrapulmonary tuberculosis.
METHODS
With the study subjects of 72 patients (57 with pulmonary tuberculosis, 15 with extrapulmonary tuberculosis) and controls of 60 persons, we performed the AFB stain, culture, PCR-ybridization and serologic test using an ICT(R) tuberculosis kit (AMRAD, Australia). Then, we compared diagnostic results in each tests and the effect of multiple tests among various methods.
RESULTS
In 57 pulmonary tuberculosis patients, 42 (73.7%) showed positive with AFB stain, 40 (70.2%) with culture, 53 (93.0%) with PCR-ybridization, 47 (82.5%) with serologic test. And in 15 extrapulmonary tuberculosis patients, 4 showed positive (26.7%) with AFB stain, 5 (33.3%) with culture, 7 (46.7%) with PCR-ybridization method, and 12 (80.0%) with serologic test. In 72 tuberculosis patients, 67 (93.1%) showed positive for any of more than 2 tests among the 4 testing methods; and among 3 testing methods combined in different ways, 53 (73.6%) to 60 (83.3%) showed positive of any of more than 2 tests.
CONCLUSIONS
We think that using the traditional method of detecting bacteria together with PCR-ybridization or serologic test would be a fast and accurate method of diagnosing tuberculosis. Especially, in those cases with extrapulmonary tuberculosis or taking a specimen of sputum is difficult, we think that serologic test would help in the diagnosis.