Diagnostic Utility of a Rapid ICT Tuberculosis Assay for the Diagnosis of Pulmonary Tuberculosis / 대한임상미생물학회지

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, Syndey, 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.

The Clinical significance of STAT-PAT-PAK ULTRA FAST(R) and ICT Tuberculosis for Serologic Diagnosis of Tuberculosis / 결핵

BACKGROUND: In recent years, tuberculosis has re-emerged as a major health problem in both industrialized and developing countries. Recent advances in identifying and purifying antigens secreted in active tuberculosis infection have lead to the development of serological assays based on a number of immunodominant antigens. To date, the most sensitive and specific of these antigens has been the 38-kDa antigen. METHOD: Two rapid membrane-based serologic assays using antigen(38-kDa) from mycobacterium tuberculosis for the diagnosis of tuberculosis were evaluated in 22 patients with smear-positive pulmonary tuberculosis, 14 patients with inactive pulmonary tuberculosis, and 9 patients with non-tuberculous lung disease. RESULT: The evaluation of validity(sensitivity, specificity, positive predictive value, negative predictive value, false positivity and false negativity) of STAT-PAK ULTRA FAST(R) were 77.3%, 28.6%, 63.0%, 44.4%, 71.4%, and 22.7% for differential diagnosis of active pulmonary tuberculosis and inactive pulmonary tuberculosis, respectively. The evaluation of validity of STAT-PAK ULTRA FAST(R) were 77.3%, 33.3%, 73.9%, 37.5%, 66.7%, and 22.7% for differential diagnosis of active pulmonary tuberculosis and non-tuberculosis. The evaluation of validity of ICT Tuberculosis were 54.5%, 57%, 66.7%, 44.4%, 42.9%, and 45.5% for differential diagnosis of active pulmonary tuberculosis and inactive pulmonary tuberculosis. The evaluation of validity of ICT Tuberculosis were 54.5%, 100%, 100%, 47.4%, 0%, and 45.4% for differential diagnosis of active pulmonary tuberculosis and non-tuberculosis. CONCLUSION: We concluded no effectiveness of STAT-PAK ULTRA FAST(R) and ICT tuberculosis on serologic diagnosis of pulmonary tuberculosis. In the future, further large-scale study should be needed for serologic diagnosis of pulmonary tuberculosis.

The Usefulness of Serologic Diagnosis for Tuberculosis with Two Rapid Immunochromatographic Assay Devices / 결핵

BACKGROUND: Many diagnostic tests have developed to diagnose tuberculosis and other mycobacterial diseases but the diagnosis of tuberculosis relies largely on radiological findings and acid-fast staining of sputum and/or culture. Recently, new serologic diagnostic methods, which are safe and easy to use have been introduced into Korea. In this study, the usefulness of serologic diagnosis for tuberculosis and the disease pattern induced variation of the test were evaluated. METHODS: Serological assay was performed upon 108 patients with two test kits, the ICT tuberculosis and the BioSign(TM) TB, which are based upon a rapid immunochromatographic assay technique, capable of being interpreted within 15 minutes. The case groups consisted of 61 patients with active pulmonary tuberculosis(36 patients), extrapulmonary tuberculosis(3 patients), or both (22 patients). Control groups consisted of 47 patients with inactive old pulmonary tuberculosis (17 patients), nontuberculous pulmonary disease(16 patients) and nonpulmonary cardiac disease(14 patients). RESULTS: The diagnostic sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the ICT tuberculosis were 64.3%, 91.5%, 90.0% and 68.3% respectively. The diagnostic sensitivity, specificity, PPV and NPV of the BioSign(TM) TB were 76.5%, 95.3%, 94.1% and 78.8% respectively. Differences in sensitivity were not significant between patients with previous history of tuberculosis or patients without prior history of tuberculosis. The ICT tuberculosis test showed higher sensitivity in pulmonary tuberculosis patients (76.5%) than extrapulmonary tuberculosis patients (33.3%). There was no difference in sensitivity between patients with or without cavitary lesion by chest X-ray. CONCLUSION: Considering high specificity and PPV, serologic diagnosis using a rapid immunochromatographic assay device is another helpful diagnostic method in the diagnosis of tuberculosis, when combined with previous diagnostic methods such as chest X-ray, microbiologic study but it has limitation in terms of confirming the diagnosis for tuberculosis as the only diagnostic method because of relatively low sensitivity and NPV.