• Tuberculosis and Respiratory Diseases
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• v.87 no.3
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• pp.302-308
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• 2024

In cases where pulmonary tuberculosis (PTB) is not microbiologically diagnosed via sputum specimens, bronchoscopy has been the conventional method to enhance diagnostic rates. Although the additional benefit of bronchoscopy in diagnosing PTB is well-known, its overall effectiveness remains suboptimal. This review introduces several strategies for improving PTB diagnosis via bronchoscopy. First, it discusses how bronchoalveolar lavage or an increased number of bronchial washings can increase specimen abundance. Second, it explores how thin or ultrathin bronchoscopes can achieve specimen acquisition closer to tuberculosis (TB) lesions. Third, it highlights the importance of conducting more sensitive TB-polymerase chain reaction tests on bronchoscopic specimens, including the Xpert MTB/RIF assay and the Xpert MTB/RIF Ultra assay. Finally, it surveys the implementation of endobronchial ultrasound with a guide sheath for tuberculomas, collection of post-bronchoscopy sputum, and reduced use of lidocaine for local anesthesia. A strategic combination of these approaches may enhance the diagnostic rates in PTB patients undergoing bronchoscopy.

• Tuberculosis and Respiratory Diseases
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• v.59 no.3
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• pp.257-265
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• 2005

Background : Rifabutin (ansamycin) is a spiro-piperidyl rifamycin, which is highly active against Mycobacterium tuberculosis. It has been found that some clinical isolates of tubercle bacilli that are resistant to rifampicin are susceptible to rifabutin, with some patients with multi-drug resistant pulmonary tuberculosis having shown favorable clinical and bacteriological responses to the rifabutin. This study was conducted to find the proportion of rifabutin-susceptible strains among rifampicin-resistant isolates from Korean MDR-TB patients, and investigate the presence of specific rpoB mutations, which may confer resistance to rifampicin, but not to rifabutin. Methods : 201 rifampicin-resistant and 50 pan-susceptible M. tuberculosis isolates were randomly selected for this study. The isolates were retested at rifampicin and rifabutin concentrations of 0, 20, 40 and $80{\mu}g/ml$, respectively. The isolates that grew at and/or over a rifabutin concentration of $20{\mu}g/ml$ were judged rifabutin-resistant. The rpoB gene was extracted from the isolates, and then amplified for direct sequencing to investigate specific rpoB mutations that conferred rifabutin- susceptibility but rifampicin-resistance. Results : Out of the 201 rifampicin-resistant M. tuberculosis, 41 strains (20.4%) were susceptible to rifabutin using the absolute concentration method on Lowenstein-Jensen media. The rpoB mutation types that showed susceptibility to rifabutin were Leu511Pro, Ser512Arg, Gln513Glu, Asp516Ala, Asp516Gly, Asp516Val, Asp516Tyr, Ser522Leu, His526Asn, His526Leu, His526Cys, Arg529Pro and Leu533Pro. A reverse hybridization technique was able to detect 92.5% of the rifabutin-susceptible isolates, with a specificity of 96.1% among 195 M. tuberculosis isolates with the rpoB mutation. Conclusions : Around 20% of the rifampicin-resistant isolates in Korea showed susceptibility to rifabutin, which was associated with some specific mutations of rpoB. Rifabutin could be used for the treatment of MDR-TB patients, especially when drug susceptibility testing reveals susceptibility to rifabutin.

• Tuberculosis and Respiratory Diseases
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• v.46 no.4
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• pp.473-480
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• 1999

Background: Early diagnosis of tuberculosis is critical, especially in Korea, an area where tuberculosis is endemic. Because antibody responses to some membrane proteins of Mycobacterium tuberculosis are not comparable, and the policy of BCG vaccination and the prevalence of tuberculosis are different from country to country, the usefulness of the serological diagnostic tests is questionable in Korea, even though they have been confirmed to be useful in other countries. In the specific context of Korea, we tried to evaluate the validity of the ICT Tuberculosis Test (ICT), a membrane-based antibody kit that purports to detect the 5 M. tuberculosis complex-specific antigens including 38-kDa protein. Method: 68 patients with tuberculosis were tested : 37 had no history of previous tuberculosis, and 31 were reactivated cases. The control group comprised 77 subjects : 25 healthy adults, 35 hospital workers with frequent contact with tuberculosis patients, and 17 in-patients with non-tuberculous respiratory diseases. Results: The diagnostic sensitivities of the ICT were 87% and 73% in patients with versus without previous history of tuberculosis, respectively. The sensitivities of smear-positive and smear-negative patient groups were 81% and 73%, respectively. Both of the two patients with extrapulmonary tuberculosis tested positive through the ICT. The specificities of the ICT were 88%, 94%, and 94% in healthy adults, hospital workers, and non-tuberculous patients, respectively, with an overall specificity of 92%. Conclusion: It is suggested that when combined with traditional techniques, the ICT is an useful tool for the diagnosis of pulmonary tuberculosis. The procedure is simple, easy to perform, rapid, and needs no equipment. It shows 73% sensitivity and 92% specificity for the diagnosis of tuberculosis.

• Tuberculosis and Respiratory Diseases
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• v.48 no.3
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• pp.315-323
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• 2000

Background : An immunochromatographic assay (ICT Diagnostics) which facilitates the diagnosis of tuberculosis(TB) by detecting serum antibodies mainly directed against specific 38KDa of Mycobacterium tuberculosis has come into the market. The test consists of a cardboard folding device containing nitrocellulose strip and absorbent pads. The whole procedure is completed within 15 min and does not require any additional equipment. The test has been reported to be sensitive and specific in diagnosing active TB. Thus the test had been evaluated with sera from TB patients and TB-free subjects. Method : Sera from patients with active pulmonary tuberculosis(40 sputum positives for Mycobacterium tuberculosis, 79 sputum negatives, and 3 extrapulmonary tuberculosis) were obtained from the Double-Cross Chest Clinic of the Korean National Tuberculosis Association (KNTA) in Seoul. The control group consisted of TB-free 68 subjects(21 children under 7 years old and 47 healthy staff members of KNTA). Results : Nine out of 68(13.2%) TB-free controls had positive antibody response. Total 106 of 122(86.9%) radiologically active patients had positive antibodies while 16 (13.1%) showed negative reaction. Antibody was detected in 38 of 40(95.0%) sputum positive patients and 68 of 82(82.9%) sputum negative patients who were under the antituberculosis chemotherapy. The sensitivity and specificity were all 87% and the positive predictive value was 92.2% while the negative predictive value was 78.7%, when the prevalence of TB in the sample was 64.2%. Our results clearly show that the detection of antibodies which mainly react with the 38KDa antigen of M. tuberculosis is not suitable as the first-line method of diagnosis but considered only as an adjunctive test to standard techniques of tuberculosis diagnosis. when considering its high false positivity.

• Tuberculosis and Respiratory Diseases
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• v.41 no.3
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• pp.239-247
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• 1994

Background: T cell mediated immunity is important in the defense mechanism of tuberculosis. Since ${\gamma}{\delta}$ T cell receptor was found to react with 65 kD heat shock protein of M.tuberculosis, there have been some reports on the role of ${\gamma}{\delta}$ T cells in the defense against M.tuberculosis. But until now, the role of the ${\gamma}{\delta}$ T cells in tuberculosis is not clear. Methods: We therefore measured the percentage of ${\gamma}{\delta}$ T cells of peripheral blood by flowcytometry before and after stimulation with Con-A, PPD and H37Ra lysate and compared between tuberculosis patients and healthy controls. Results: ${\gamma}{\delta}$ T cells of pheripheral blood in pulmonary tuberculosis patients was $7.5{\pm}5.2%$, showing no difference compared with healthy control($10.0{\pm}4.8%$). But IL-2R(+) ${\gamma}{\delta}$ T cells were higher in tuberculosis compared with healthy control($4.8{\pm}5.1%$ vs. $1.8{\pm}2.8%$). After stimulation with PPD or Con-A, the percentage of ${\gamma}{\delta}$ T cells showed no significant change, but IL-2R(+) ${\gamma}{\delta}$ T cells increased significantly in both tuberculosis($17.9{\pm}13.4%,\;57.6{\pm}20.2%$ respectively) and healthy control group($11.5{\pm}9.1%,\;80.8{\pm}9.3%$). After stimulation with H37Ra lysate, percentage of ${\gamma}{\delta}$ T cells showed increasing tendency in healthy control group, but it was not statistically significant. Conclusion: In this study, we could not demonstrate the role of ${\gamma}{\delta}$ T cells in the peripheral blood of pulmonary tuberculosis. It is suggested that further studies will be needed in the regional sites of M.tuberculosis infection.

• Tuberculosis and Respiratory Diseases
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• v.43 no.6
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• pp.842-851
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• 1996

Background : Rifampicin(RFP) is a key component of the antituberculous shon-course chemotherapy and the RFP-resistance is a marker of multi-drug resistant(MDR) M. tuberculosis. rpoB gene encodes the ${\beta}$-subunit of RNA polymerase of M. tuberculosis which is the target of RFP. Recent reports show that rpoB gene mutations are the cause of RFP resistance of M. tuberculosis and the main mechanism of rpoB gene mutation is point mutation. And PCR-SSCP is a rapid and easy method for detecting point mutations. So we performed PCR-SSCP of rpoB gene of M. tuberculosis and compared the result with traditional RFP sensitivity test. Method : The 27 RFP sensitive M. tuberculosis culture isolates and 25 RFP resistant isolates were evaluated. The RFP sensitivity test was done at the Korean Tuberculosis istitute. The DNA was extracted by bead beater method and was amplified with primers TR-8 and TR-9 in a 20ul PCR reaction containing 0.1ul(luCi) [${\alpha}-^{32}P$] - dCTP. After amplification, SSCP was done using non-denaturaring polyacrylamide gel electrophoresis. Then direct sequencing was done in cases of different eletrophoretic mobility compared with that of H37Rv. In 19 cases, we compared PCR-SSCP results with patient's clinical course and the results of traditional RFP sensitivity test. Results : 1) All 27 RFP sensitive M. tuberculosis isolates showed the same electrophoretic mobility compared with that of H37Rv. And all 25 RFP resistant M. tuberculosis isolates showed different electrophoretic mobility. 2) The mechanism of rpoB gene mutation of M. tuberculosis is mainly point mutation. 3) The PCR-SSCP results correlate well with traditional RFP sensitivity and patient's clinical response to antituberculous treatment. Conclusion: The PCR-SSCP of rpoB gene is a very sensitive and rapid mehod in detecting RFP- resistant M. tuberculosis.

• Tuberculosis and Respiratory Diseases
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• v.43 no.2
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• pp.138-146
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• 1996

Background : Known as a kind of complication or a specific form of pulmonary tuberculosis, endobronchial tuberculosis caused several kinds of problems in diagnosis and managements. But the frequency of this disease are is widely variable, generally reported from as low as 10 - 20 % to as high as 40 - 50 %. We prospectively performed bronchoscopy in patients diagnosed as pulmonary tuberculosis to evaluate the frequency of endobronchial tuberculosis and its related findings. Method : From March, 1995 to February, 1996, we prospectively performed bronchoscopy in patients newly diagnosed as pulmonary tuberculosis and evaluated the frequency of endobronchial tuberculosis, its clinical features and laboratory findings including raiologic, microbiologic and physiologic aspects. Results : Number of patients diagnosed as pulmonary tuberculosis was 103 and 55 patients(53.4%) were found to have endobronchial tuberculosis. But the frequency were 43.8% in male and 76.7% in female, respectively. Frequently noted symptoms were nonspecific including cough, sputum, fever, weight loss in the order of frequency but cough was more frequent than in pulmonary tuberculosis. Physical examination showed rale, decreased breathing sound and wheezing and wheezing was more frequent than in pulmonary tuberculosis. All 7 subtypes were noted bronchoscopically and edema-hyperemia (stenotic without fibrosis) type was most frequently(32.7%) noted, and followed by chronic nonspecific bronchitis type, stenotic with fibrosis type and actively caseating type in the order of frequency. The relationship between subtypes of endobronchial tuberculosis and radiologic findings was insignificant. Right lung was involved more frequently than left lung and left upper lobe was most commonly involved site, and followed by right upper lobe and trachea. Acid-fast bacilli(AFB) positivity in sputum and / or bronchial washing fluid was 73% and suggested high risk of infectivity. Conclusion : The frequency of endobronchial tuberculosis in patients with pulmonary tuberculosis was higher than known and also suggested bronchoscopic examination to detect endobronchial involvement should be recommanded and careful management is also needed to prevent complications.

• Tuberculosis and Respiratory Diseases
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• v.56 no.3
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• pp.268-279
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• 2004

Background : The tuberculin skin test has been used to diagnose latent tuberculosis infection, but is not widely used to diagnose or exclude pulmonary tuberculosis. The objective of this study was to evaluate the diagnostic utility of the tuberculin test in diagnosing and excluding pulmonary tuberculosis, and differentiating pulmonary tuberculosis from nontuberculous mycobacteria (NTM) pulmonary disease, when a sputum acid-fast bacilli (AFB) smear was positive. Material and Methods : From October 2002 to August 2003, among all the inpatients of the Division of Pulmonary and Critical Care Medicine at Samsung Medical Center, 258 patients with clinical suspicion of pulmonary tuberculosis were enrolled and underwent a tuberculin test. Results : 156 males and 102 females were included, with a mean age of 57.5 years. The final diagnoses included lung cancer in 89 cases (34.5%), pulmonary tuberculosis in 59 cases (22.9%), bacterial pneumonia in 33 cases (12.8%) and NTM pulmonary disease in 24 cases (9.3%). The positive tuberculin test rate was higher in the tuberculosis than non-tuberculosis group; 81.4 (48/59) vs. 42.4% (81/199). (p<0.001). In 208 patients with a negative sputum AFB smear, the result of the tuberculin test was positive in 69.4% (25/36) of the tuberculosis group and in 44.8% (77/172) of the non-tuberculosis group (p=0.007), so a positive result of the tuberculin test could predict pulmonary tuberculosis with 69.4% sensitivity, 55.2% specificity, a 24.5% positive predictive value and a 89.6% negative predictive value. In 50 patients with a positive sputum AFB smear, the positive rates of the tuberculin test were 83.9% (26/31) in tuberculosis group and 21.1% (4/19) in NTM pulmonary disease group (p<0.001), so a positive result of the tuberculin skin test could predict pulmonary tuberculosis with 83.9% sensitivity, 78.9% specificity, a 86.7% positive predictive value and a 75.0% negative predictive value. Conclusion : The tuberculin test could be useful in excluding pulmonary tuberculosis when the sputum AFB smear is negative, and to differentiate pulmonary tuberculosis from NTM pulmonary disease when the sputum AFB smear is positive.

• Tuberculosis and Respiratory Diseases
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• v.80 no.2
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• pp.210-211
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• 2017

• 보건세계
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• v.53 no.11 s.603
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• pp.47-49
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• 2006

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