• Tuberculosis and Respiratory Diseases
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• v.53 no.4
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• pp.401-408
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• 2002

Background : Tuberculin skin test is a method to examine M. tuberculosis infection and has been used all over the world. But various factors make it difficult to understand testing results. In 2000, the American Thoracic Society recommended that skin test results should be decided by considering risk factors of the tested. In Korea, high tuberculosis infection rate and BCG vaccination rate make it difficult to differentiate current infection, past infection, and no infection by the skin test. This study was attempted to examine a negative predictive value of the skin test to understand how the skin test acts on deciding administration of anti-tuberculosis drug. Methods : From Mar. 1 to Jul. 31 in 2001, the test was performed for patients hospitalized in Department of Internal Medicine, Hallym University College of Medicine, Chunchon, Korea by administering Tuberculin PPD RT23 2 TU (0.1 ml)to them that has been currently used in Korea based on Mantoux method. They were decided to be infected with tuberculosis bacilli by following diagnostic standard: 1) tuberculosis bacilli was cultured in sputum by microbiological diagnostic standard or Acid-fast bacilli was proven on a microscopic examination or 2) tuberculosis bacilli was not proven in the aforesaid microbiological test by clinical diagnostic standard, while there was opinion or symptom suitable for tuberculosis by radiographic or histological standard so the doctor decided to apply the tuberculosis treatment. Results : In this study, total 210 patients except 20 patients (8.7%) among 230 hospitalized patients were evaluated. Their average age was 60±16.8 years, and male-female rate was 1.28 : 1 (male: 118, female: 92). Number of patient, who was diagnosed and decided as tuberculosis, was 53(25.2%). Pulmonary tuberculosis was found in 45 patients (84.9%); 22 patients were decided to be positive in the Acid-fast bacilli smear test by microbiological examination (culture positive: 13, culture negative: 9), and 23 patients were decided to be tuberculosis patients by clinical diagnosis standard. Tuberculosis pleuritis was found in 8 patients (15.1%); 4 patients were diagnosed and decided by histological standard, and 4 patients were decided and treated by clinical standard. In differentiating patients into 'Negative' and 'Positive' by the skin test standard of the American Thoracic Society, negative predictive value 92.3%, positive predictive value 47.3%, sensitivity and specificity were 83%, 68.8%, respectively. Conclusion : In hospitalized respiratory patients, there was high negative predictive vlaue 92.3% by tuberculin skin test, therefore skin test would be a important factor for deciding administration of anti-tuberculosis drug on negative skin test patient.

• Tuberculosis and Respiratory Diseases
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• v.39 no.1
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• pp.62-72
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• 1992

Background: T-cell mediated cellular immunity has been suggested as an important mechanism in mycobacterial infection and imbalance between helper/inducer and suppressor/cytotoxic T-cell has been suggested as an important immunological abnormality in the pathogenesis of tuberculosis in human. Method: To determine whether there is any difference in T-cell mediated immunity in the pathogenesis of pulmonary and extra pulmonary tuberculosis, total numbers of WBC&lymphocytes were counted and helper/inducer and suppressor/cytotoxic cells were calculated by flow cytometry. Blastogenesis after stimulation with Concanavalin-A, Phytohemagglutinin and PPD were measured by $^3H$-thymidine uptake. PPD skin test was performed as an in vivo test. Results: 1)There was no significant difference in the size of PPD skin test between pulmonary and extrapulmonary tuberculosis groups. 2)Number of total lymphocytes significantly decreased in tuberculosis patients compared with healthy control group. But there was no significant difference between pulmonary and extrapulmonary tuberculosis groups. 3) Number of HLA-DR and Interleukin-2 receptor (+) cells were significantly increased in tuberculosis patients. But there was no significant difference between pulmonary and extra pulmonary tuberculosis groups. 4) There was no significant difference in the numbers of WBC, $T_3$, $T_4$ and $T_8$ lymphocytes and $T_4/T_8$ ratio between tuberculosis patients and healthy controls. 5) There was no significant difference in the blastogenesis after stimulation with specific and non-specific blastogens between tuberculosis patients and healthy controls. 6) The percentage and absolute number of $T_4$ lymphocyte were significantly correlated with the size of PPD skin test. (r=0.689 and 0.598). Conclusion: From these results, it is concluded that there was no difference in T-cell mediated immunity between pulmonary and extra pulmonary tuberculosis group. But, because it is suspected that there might be some difference in the role of T-cell mediated immunity in the pathogenesis of pulmonary and extra pulmonary tuberculosis or even among the extrapulmonary tuberculosis patients, further studies would be required.

• Tuberculosis and Respiratory Diseases
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• v.47 no.6
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• pp.757-767
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• 1999

Background: Diagnosis by smear and/or cultures of the Mycobacterium tuberculosis from body fluid or biopsy specimen is "Gold standard". However the sensitivity of the direct microscopy is relatively low and culture of mycobacteria is time consuming. Despite an explosion in the techniques of rapid identification of mycobacteria by molecular genetic means, it is laborious and expensive and then rapid, inexpensive serodiagnosis is interested in diagnosis of tuberculosis. But sensitivity and specificity of known serologic antigen is not full sufficient level and then new antigen develop and combination cocktails of new developed antigens by ELISA are needed. Method: To compare the efficacy of different mycobacterial specific antigen and to assess the applicability of the combination of several different antigens in the diagnosis of tuberculosis, five ELISA tests derived 14KDa, 16KDa, 19KDa, 23KDa, 38KDa were evaluated in 57 active pulmonary patient and 24 inactive post-therapy follow up patient and 48 normal control. Results: The optical densities of ELISA test with 14KDa, 16KDa, 19KDa, 23KDa, 38KDa were significantly higher in active tuberculosis cases than in normal control(P<0.001, P<0.001, P<0.027, P<0.001, P<0.001) and those with 16KDa, 38KDa were significant higher in active tuberculosis cases than in inactive post-therapy follow up cases(P<0.01. P<0.001) and those of 14KDa, 16KDa, 23KDa, 38KDa were significant higher in inactive post-therapy follow up cases than in normal control(P<0.008. P<0.01. P<0.006. P<0.001). The sensitivity of 14KDa, 16KDa, 19KDa, 23KDa, 38KDa in active pulmonary patient cases was 42.1%, 43.9%, 15.8%, 28.0%, 70.2%, respectively and the specificity of 14KDa, 16KDa, 19KDa, 23KDa, 38KDa in active pulmonary patient cases was 95.8%, 95.8%, 91.7%, 89.6%, 93.8%, respectively. The sensitivity and specificity of combination 38KDa with 16KDa was 87% and 93.7%. Conclusion: The sensitivity and specificity of new antigens for serodiagnosis of the tuberculosis still remains limited at around 70%, which makes its a poor diagnostic tool for disease confirmation. A combination of cocktail antigens provided by cut-off value adjustment for serodiagnosis of tuberculosis some improved diagnostic yield than single antigen serologic test.

• Tuberculosis and Respiratory Diseases
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• v.66 no.1
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• pp.13-19
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• 2009

Background: The interferon-gamma assay is reported to have high sensitivity and specificity for making the diagnosis of latent tuberculosis infection. The clinical usefulness of this essay for detecting active tuberculosis has not fully defined. We evaluated the diagnostic value of the commercial interferon-gamma assay kit (QuantiFERONTB GOLD) for patients with suspected tuberculosis. Methods: From January to August 2007, we recruited 52 patients with suspected tuberculosis infection. We performed chest X-ray, sputum smear, culture, PCR and the QuantiFERON-TB GOLD test. Pleural fluid analysis and pleural biopsy were also done for the patients with pleural effusion. Results: Of the 52 patients we studied, 30 patients had a positive QuantiFERON-TB GOLD test result. 35 patients were finally diagnosed with active tuberculosis: twenty-five with a positive QuantiFERON-TB GOLD test and 10 with a negative QuantiFERON-TB GOLD test. The sensitivity of the QuantiFERON-TB GOLD test was 71.4% and the specificity was 64.7%. The positive predictive value was 0.83 and the negative predictive value was 0.50. There was no significant difference of any of the clinical and laboratory characteristics between the two groups of patients except the C-reactive protein (CRP) level. The CRP level was 29.2${\pm}$27.3 mg/dL in the pulmonary tuberculosis patients with a positive QuantiFERON-TB GOLD test and 72.9${\pm}$67.9 mg/dL in the patients with a negative QuantiFERON-TB GOLD test (p<0.05). Conclusion: The sensitivity and specificity of the QuantiFERON-TB GOLD test were inadequate for making the diagnosis of active tuberculosis. We suggest that the QuantiFERON-TB GOLD test should not be used by itself to exclude the diagnosis of active tuberculosis. The relationship of the QuantiFERON-TB GOLD test and the CRP level in patients with TB would be further investigated.

• Journal of the Korean Society of School Health
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• v.28 no.3
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• pp.177-187
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• 2015

Purpose: This study was conducted to examine tuberculosis-related knowledge, attitude and preventive behaviors of middle school students and to investigate socio-demographic and health-related factors. Methods: 198 male and 188 female middle school students in M city were recruited for the survey. Independent sample t-test, One-way ANOVA and $Scheff{\acute{e}}^{\prime}s$ test and Pearson's correlation were performed to examine factors associated with tuberculosis-related knowledge, attitude and preventive behaviors. Results: The percentage of correct answers to questions testing tuberculosis-related knowledge was very low, 33%. The mean scores of attitude and preventive behaviors were 3.02 and 2.90 out of 4 (highest score), respectively. Middle school students who had experiences of health education or tuberculosis-related education showed significantly higher scores than their counterparts in all factors - knowledge, attitude, and preventive behaviors. Parental education, academic achievement, smoking, sleeping time, infectious disease education, and source of tuberculosis information were associated with knowledge, attitude, and preventive behaviors. Knowledge about tuberculosis had a positive correlation with attitude and preventive behaviors. Conclusion: The level of tuberculosis-related knowledge, attitude, and preventive behaviors was very low among middle school students. In addition, school health education was highly related to a higher level of knowledge, attitude, and preventive behaviors regarding tuberculosis. Therefore, to intensify students' preventive behaviors against tuberculosis and other infection diseases, sustainable school health education should be provided for middle school students who are at risk of developing tuberculosis.

• Tuberculosis and Respiratory Diseases
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• v.60 no.5
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• pp.497-509
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• 2006

Until recently, the tuberculin skin test (TST) has been the only tool available for diagnosing a latent TB infection. However, the development of new diagnostic tools, using the Mycobacterium tuberculosis (MTB)-specific early secreted antigenic target 6 (ESAT-6) and culture filtrate protein 10 (CFP-10) antigens, should improve the control of tuberculosis (TB) by allowing a more accurate identification of a latent TB infection (LTBI). Antigen-specific interferon-gamma ($IFN-{\gamma}$) assays have greater specificity in BCG-vaccinated individuals, and as less biased by nontuberculous mycobacterial infections. Many comparative studies have suggested that those assays have a higher specificity than the TST, and the sensitivity of these assays are expected to remarkably improved if more MTB-specific antigens can become available. Nevertheless, the major obstacle to the widespread use of these tests is the limited financial resources. Similar to other diagnostic tests, the predictive value of $IFN-{\gamma}$ assays depends on the prevalence of a MTB infection in the population being tested. Therefore, prospective studies will be meeded to establish the applicability of these new assays at multiple geographic locations among patients of different ethnicities, and to determine if the $IFN-{\gamma}$ responses can indicate those with a high risk of progressing to active TB.

• Tuberculosis and Respiratory Diseases
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• v.85 no.3
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• pp.264-272
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• 2022

Background: The current conventional drug susceptibility test (DST) for Mycobacterium tuberculosis (Mtb) takes several weeks of incubation to obtain results. As a rapid method, molecular DST requires only a few days to get the results but does not fully cover the phenotypic resistance. A new rapid method based on the ability of viable Mtb bacilli to hydrolyze fluorescein diacetate to free fluorescein with detection of fluorescent mycobacteria by flow cytometric analysis, was recently developed. Methods: To evaluate this cytometric method, we tested 39 clinical isolates which were susceptible or resistant to isoniazid (INH) or rifampin (RIF), or ethambutol (EMB) by phenotypic or molecular DST methods and compared the results. Results: The susceptibility was determined by measuring the viability rate of Mtb and all the isolates which were tested with INH, RIF, and EMB showed susceptibility results concordant with those by the phenotypic solid and liquid media methods. The isolates having no mutations in the molecular DST but resistance in the conventional phenotypic DST were also resistant in this cytometric method. These results suggest that the flow cytometric DST method is faster than conventional agar phenotypic DST and may complement the results of molecular DST. Conclusion: In conclusion, the cytometric method could provide quick and more accurate information that would help clinicians to choose more effective drugs.

• Pediatric Infection and Vaccine
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• v.18 no.1
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• pp.1-14
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• 2011

Tuberculosis is a disease with high morbidity and mortality in children worldwide. Despite the decrease in the incidence of tuberculosis in Korea, more than 30,000 new patients are diagnosed each year. Active tuberculosis is less frequent in children compared to adults but the risk of miliary tuberculosis and CNS tuberculosis is much higher. The diagnosis of tuberculosis in children and adolescents is difficult due to the nonspecific symptoms upon presentation. Diagnostic work up is based on the confirmation of tuberculosis infection by tuberculin skin test, abnormal radiologic findings, and contact with an adult with active tuberculosis. Anti-tuberculosis medications are prescribed according to the drug susceptibility of the index patient. Latent tuberculosis infection plays an important role in adult tuberculosis by reactivation. Thus, it is critical to accurately diagnose latent tuberculosis in children to prevent reactivation in adulthood. Korean guidelines for diagnosis and treatment of tuberculosis in children and adolescents provide evidence based recommendations in the optimal diagnosis and treatment for active and latent tuberculosis in children and adolescents based on the current Korean situation.

• Tuberculosis and Respiratory Diseases
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• v.57 no.3
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• pp.221-225
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• 2004

• Tuberculosis and Respiratory Diseases
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• v.76 no.6
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• pp.261-268
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• 2014

Patients with immune-mediated inflammatory diseases (IMIDs) are increasingly being treated with anti-tumor necrosis factor (TNF) agents and are at increased risk of developing tuberculosis (TB). Therefore, diagnosis and treatment of latent TB infection (LTBI) is recommended in these patients due to the initiation of anti-TNF therapy. Traditionally, LTBI has been diagnosed on the basis of clinical factors and a tuberculin skin test. Recently, interferon-gamma releasing assays (IGRAs) that can detect TB infection have become available. Considering the high-risk of developing TB in patients on anti-TNF therapy, the use of both a tuberculin skin test and an IGRA should be considered to detect and treat LTBI in patients with IMIDs. The traditional LTBI treatment regimen consisted of isoniazid monotherapy for 9 months. However, shorter regimens such as 4 months of rifampicin or 3 months of isoniazid/rifampicin are increasingly being used to improve treatment completion rates. In this review, the screening methods for diagnosing latent and active TB before anti-TNF therapy in patients with IMIDs will be briefly described, as well as the current LTBI treatment regimens, the recommendations for managing TB that develops during anti-TNF therapy, the necessity of regular monitoring to detect new TB infection, and the re-initiation of anti-TNF therapy in patients who develop TB.