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.

Pulmonary infection with Mycobacterium celatum in immunocompetent host: The first case report in Korea / 결핵

Mycobacterium celatum is a recently described nontuberculous mycobacterium. Even though pulmonary or lymphatic infection cases were reported previously in human, the clinical significance of the infection with M.celatum is not yet understood completely. Most infections with this species occurred in the patients with suppressed cell-mediated immunity such as AIDS, and there are only a few cases of pulmonary infection with M.celatum in immunocompetent adults or infants in the world. In Korea, mycobacterial pulmonary infection is a major problem of respiratory disease but, there has been no pulmonary infection with M. celatum reported. We report, to our knowledge, the first Korean case of pulmonary infection with M. celatum, which was identified by gamma poB genomic sequencing.

The first case of summer-type hypersensitivity pneumonitis in Korea / 결핵

We report the first case of summer-type hypersensitivity pneumonitis(SHP) in Korea diagnosed by positive serum antibodies to Trichosporon cutaneum. Hypersensitivity pneumonitis(HP) has been commonly classified as an occupational respiratory diseases. However, evidence that sensitizing organisms can also contaminate and cause pulmonary diseases in home environment has been increasing. One such disease is SHP. In Japan, 75% of cases with HP are SHP. Even though there has been no known SHP case in Korea yet, there has been high possibility of SHPs in Korea because our country has areas which have hot and humid summer climate similar to Japan. This first case of SHP in Korea suggests that there may be another cases in Korea and nation-wide survey may be required. We report here the first confirmed case of SHP in Korea.