• Tuberculosis and Respiratory Diseases
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• v.58 no.3
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• pp.248-256
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• 2005

Background : Nontuberculous mycobacterial (NTM) infections are increasingly being recognized as a cause of chronic pulmonary disease. This study describes the prevalence of NTM species from clinical specimens and the clinical characteristics of NTM pulmonary disease. Material and Methods : The NTM isolated from March 2003 to December 2003 at the Kosin Medical Center were identified using an oligonucleotide chip containing the internal transcribed space (ITS) sequence. The medical records of the patients with the NTM isolates, who fulfilled the 1997 ATS diagnostic criteria for NTM pulmonary disease, were analyzed, retrospectively. Results : Twenty four species (24.2%) of NTM were isolated from 99 cultured AFB specimens. M. avium complex (MAC) (13 isolates), M. szulgai (3), M. kansasii (2), M. malmoense (2), M. abscessus (1), M. chelonae (1), M. scrofulaceum (1), and unclassified (1). Of the 23 patients with isolated NTM, 11 patients were found to be compatible with a NTM pulmonary infection according to the ATS criteria; MAC was found in 6 cases (54.5%), M. szulgai in 2 cases (18.2%), and M. abscessus, M. szulgai, M. kansasii and M. malmoense in 1 case each (9.1%). Ten patients (91%) were male and the median age at diagnosis was 61 years. In the pre-existing diseases, malignant disease was found in 6 cases including 5 patients with lung cancer, and history of old pulmonary tuberculosis was identified in 4 cases. The radiological patterns showed lung destruction lung in 3 cases, a cavitary mass in 3 cases, a nodular pattern in 2 cases, and reticulonodular, consolidation and a bronchiectasis pattern were in 1 case each. Conclusion : Various types of NTM pulmonary diseases were found in a tertiary hospital at Busan, Korea. The NTM pulmonary diseases were caused by MAC, M. szugai, M. kansasii, M. malmoense, M. abscessus, M. chelonae, and M. scrofulaceum in the order of frequency.

• Tuberculosis and Respiratory Diseases
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• v.47 no.6
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• pp.747-756
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• 1999

Background: Acid-fast stain and cultures for diagnosis of pulmonary tuberculosis are primary and essential method, but have their limitation : low sensitivity and time consuming. The objective of this study is comparison of amplified Mycobacterium tuberculosis direct test(MTD) by the conventional AFB smears and cultures in the detection of Mycobacterium tuberculosis in respiratory specimens. Methods: During the period between November, 1997 and May, 1998 a total of 267 respiratory specimens (sputum 173, bronchial washing 94) from 187 patients suspected pulmonary tuberculosis were subjected to AFB smears, cultures and MID test. MID is based on nucleic acid amplification. We compared the MID with 3% Ogawa culture method. In positive AFB smear and negative MID specimen, positive culture identification between nontuberculous mycobacterium and M.tuberculosis was assesed by using Accuprobe M.tuberculosis complex probe. In negative AFB smear and negative AFB culture, MTD results are assessed by clinical follow-up. Results : 1) Compared with culture in sputum and bronchial fluid specimens, sensitivity and specificity of MTD in positive AFB smear is 79.7% and 20.0%, sensitivity and specificity of MTD in negative AFB smear specimens is 75.0% and 79.7%. 2) Discrepant analysis is assessed by clinical follow-up and other specimen results beyond study. Culture negative but MTD positive specimens were proved to be true positive and gave MTD sensitivity 79.2%, specificity of 84.4%, positive predictive value 80.5% and negative predictive value 83.2%. 3) 14 out of 31 specimens in negative AFB smear, negative AFB culture and positive MTD showed pulmonary tuberculosis diagnosed on clinical follow-up and sensitivity is 45.2%. 4) 2 out of 13 specimens in positive AFB smear, positive AFB culture and negative MID diagnosed as non tuberculous mycobacterium by Accuprobe culture. Conclusion: This study suggested that MID in respiratory specimens is simple and rapid diagnostic method, but considered adjuvant method rather than replace the conventional AFB smear and culture.

• Tuberculosis and Respiratory Diseases
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• v.39 no.5
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• pp.425-432
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• 1992

Background: The prevalence of tuberculosis in Korea decreased remarkably for the past 30 years, while for at least the recent 10 years, the frequency of disease attributable to mycobacteria other than tuberculosis (MOTT) began to increase both in actual numbers and in the proportion of the total burden of mycobacterioses. Method: Twenty nine cases, diagnosed as having pulmonary disease due to MOTT on the basis of repeated isolations of the relevant organisms from sputum specimens and chest X-ray findings from Jan. 1982 throught Dec. 1991 at the Chest Clinic of the Korean Institute of Tuberculosis, were reviewed in terms of clinical features and courses. Results: 1) Nineteen cases (66%) were infected with Mycobacterium avium-intracellulare, 5 cases (17%) with M. fortuitum, 4 cases (14%) with M. chelonei, and 1 cases (3%) with M. szulgai. 2) The ratio of male versus female patients was 1.9:1. 3) The peak incidence was in the fifth decade. 4) Eighteen cases (62%) had moderately advanced disease and 11 cases (38%) had far advanced disease on chest P-A film. 5) The common symptoms were cough (59%), sputum (52%), and dyspnea (34%). 6) All cases had a previous history of tuberculosis. 7) Most of the isolates were highly resistant to the major antituberculosis drugs and 48~52% showed a sensitivity to cycloserine, kanamycin or enviomycin. 8) Of 19 cases which were treated and followed-up for over 12 months, 3 cases attained negative conversion on cultures (2 M. fortuitum infections, 1 M. szulgai infection). Sixteen cases failed in attaining negative conversion on cultures. However, their clinical courses were chronic and indolent despite of persistant culture positivity. Conclusion: Treatment of these patients has been difficult because of the frequency of severe underlying conditions and the natural resistance of most of the nontuberculous mycobacteria to the presently available drugs.

• 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.54 no.1
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• pp.33-44
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• 2003

Background : Mycobacterium avium complex(MAC) is the most common respiratory pathogen in nontuberculous mycobacterial pulmonary disease. This study described the clinical characteristics of the patients with pulmonary disease caused by MAC. Materials and Methods : The clinical characteristics of 24 patients with pulmonary disease caused by the MAC, who fulfilled the 1997 American Thoracic Society diagnostic criteria for nontuberculous mycobacterial pulmonary disease, were retrospectively analyzed. Results : Fourteen patients(58%) were male and the median age at diagnosis was 61 years(range 46-75). Of the 24 patients, 16(67%) had a M. intracellulare infection, 7(29%) had a M. avium infection and one patient was not identified. Coughing (92%) and sputum (88%) were most frequently observed symptoms. The sputum smear for acid-fast bacilli was positive in 17(71%) patients. Fourteen(58%) patients had the upper lobe cavitary form and 10(42%) patients had the nodular bronchiectatic form. In a comparison between the patients with the upper lobe cavitary form and those with the nodular bronchiectatic form, significant differences were found according to sex(male 86% vs. 20%, p=0.003), smoking history(79% vs. 10%, p=0.008), the presence of an underlying disease(64% vs. 20%, p=0.036), the pulmonary function(% forced vital capacity, median 71% vs. 88%, p=0.022; % forced expiratory volume in one second, median 69% vs. 89%, p=0.051) and bilateral disease at chest radiography(29% vs. 90%, p=0.005). The time from the onset of symptoms to diagnosis was longer in those with the nodular bronchiectatic form(median 72 months, range 8-132) than those with the upper lobe cavitary form(median 22 months, range 6-60) Conclusions : MAC pulmonary disease occurs in two distinct populations with two distinct clinical presentations. For a correct diagnosis of MAC pulmonary disease, knowledge of the diverse clinical and radiological findings is essential.

• Tuberculosis and Respiratory Diseases
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• v.58 no.1
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• pp.11-17
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• 2005

Background : Interferon-gamma ($IFN-{\gamma}$) is essential in the immune response to mycobacterial infections, and a complete or partial deficiency in the $IFN-{\gamma}$ receptor 1 ($IFN{\gamma}R1$) or the $IFN-{\gamma}$ receptor 2 ($IFN{\gamma}R2$) have been reported to confer susceptibility to a disseminated infection with nontuberculous mycobacteria. However, similar mutations in the $IFN-{\gamma}$ receptor have not been specifically examined in the patients with clinical tuberculosis. Methods : This study searched for mutations in the $IFN-{\gamma}$ receptor gene that resulted in a partial $IFN-{\gamma}$ receptor deficiency in six patients with disseminated tuberculosis. The previously identified $IFN{\gamma}R1$ and $IFN{\gamma}R2$ coding regions were sequenced after amplification. Results : There was no partial $IFN{\gamma}R1$ deficiency including a homozygous recessive missense mutation causing an amino-acid substitution in the extracellular domain of the receptor (I87T) and a hotspot for small deletions (818delT, 818del4, 818insA) found in any of the patients. In addition, a partial $IFN{\gamma}R2$ deficiency of the homozygous missense mutation (R114C) was not found in any of the patients. Conclusion : Genetic defects causing a partial $IFN-{\gamma}$ receptor deficiency were not identified in our patients with disseminated tuberculosis.