[Clinical evaluation of a line probe assay kit for the identification of Mycobacterium species and detection of drug-resistant Mycobacterium tuberculosis].

BACKGROUND: Multidrug resistance (MDR) involves resistance to both isoniazid and rifampicin, which makes the treatment of tuberculosis very difficult. Extensive drug resistance (XDR) occurs when, in addition to isoniazid and rifampicin resistance, the microorganisms are resistant to a fluoroquinolone and an injectable agent (e.g., kanamycin, amikacin, or capreomycin). Generally, drug susceptibility testing takes more than 3-4 weeks after the initial cultivation. There is an urgent need to identify methods that can rapidly detect both the presence of Mycobacterium tuberculosis and the status of drug resistance. PURPOSE: This study was aimed at evaluating the line probe assay (LiPA; Nipro Co.), for the identification of Mycobacterium species and detection of mutations associated with antituberculous drugs. RESULTS: We found that LiPA enabled the rapid identification of M. tuberculosis, M. avium, M. intracellulare, and M. kansasii. When the results of the LiPA and conventional drug susceptibility tests were compared, there was no difference in the susceptibility to rifampicin, pyrazinamide, and levofloxacin; however, there was a difference in the susceptibility to isoniazid. CONCLUSION: Thus, LiPA can be used for the rapid identification of Mycobacterium species and the determination of susceptibility to drugs, which can help in the early initiation of appropriate treatment, leading to a reduction in infectiousness.

Doctor's delay in endobronchial tuberculosis.

OBJECTIVE: The aim of this study was to investigate the current status of doctor's delay in diagnosing endobronchial tuberculosis (EBTB) and to elucidate the risk factors contributing to the delay. METHODS: Retrospective clinicopathological analysis. PATIENTS: Sixty-two patients with EBTB were admitted at our hospital between 1999 and 2010. Their backgrounds, symptoms, diagnoses at initial consultation, delay in diagnosis, and clinical examination results were analyzed. RESULTS: Of the 62 patients, 59 had acid-fast, bacillipositive sputum smear test results at admission. Among the 40 patients with total diagnostic delay of more than 2 months, only 11 experienced long patient's delay exceeding 2 months. However, 22 patients experienced long doctor's delay of more than 2 months (28% vs. 55%, respectively, p < 0.05), suggesting that doctor's delay contributes more to total delay than patient's delay. Fever was less frequent in patients with long doctor's delays than in those without (0% vs. 18%, respectively), at the initial consultation. In addition, radiographs showed that patients with long doctor's delays more frequently presented with shadows in the lower lung field (50% vs. 23%, p < 0.05), and most of these patients had noncavitary shadows on admission. All 7 patients diagnosed with bronchial asthma at the initial consultation had long doctor's delays. CONCLUSION: These findings demonstrate that long doctor's delays in diagnosing EBTB remain an issue. The clinical features of EBTB with long doctor's delays were confirmed to be quite different from those of pulmonary tuberculosis.

Comprehensive multicenter evaluation of a new line probe assay kit for identification of Mycobacterium species and detection of drug-resistant Mycobacterium tuberculosis.

We evaluated a new line probe assay (LiPA) kit to identify Mycobacterium species and to detect mutations related to drug resistance in Mycobacterium tuberculosis. A total of 554 clinical isolates of Mycobacterium tuberculosis (n = 316), Mycobacterium avium (n = 71), Mycobacterium intracellulare (n = 51), Mycobacterium kansasii (n = 54), and other Mycobacterium species (n = 62) were tested with the LiPA kit in six hospitals. The LiPA kit was also used to directly test 163 sputum specimens. The results of LiPA identification of Mycobacterium species in clinical isolates were almost identical to those of conventional methods. Compared with standard drug susceptibility testing results for the clinical isolates, LiPA showed a sensitivity and specificity of 98.9% and 97.3%, respectively, for detecting rifampin (RIF)-resistant clinical isolates; 90.6% and 100%, respectively, for isoniazid (INH) resistance; 89.7% and 96.0%, respectively, for pyrazinamide (PZA) resistance; and 93.0% and 100%, respectively, for levofloxacin (LVX) resistance. The LiPA kit could detect target species directly in sputum specimens, with a sensitivity of 85.6%. Its sensitivity and specificity for detecting RIF-, PZA-, and LVX-resistant isolates in the sputum specimens were both 100%, and those for detecting INH-resistant isolates were 75.0% and 92.9%, respectively. The kit was able to identify mycobacterial bacilli at the species level, as well as drug-resistant phenotypes, with a high sensitivity and specificity.

Inter-rater agreement in the assessment of abnormal chest X-ray findings for tuberculosis between two Asian countries.

BACKGROUND: Inter-rater agreement in the interpretation of chest X-ray (CXR) films is crucial for clinical and epidemiological studies of tuberculosis. We compared the readings of CXR films used for a survey of tuberculosis between raters from two Asian countries. METHODS: Of the 11,624 people enrolled in a prevalence survey in Hanoi, Viet Nam, in 2003, we studied 258 individuals whose CXR films did not exclude the possibility of active tuberculosis. Follow-up films obtained from accessible individuals in 2006 were also analyzed. Two Japanese and two Vietnamese raters read the CXR films based on a coding system proposed by Den Boon et al. and another system newly developed in this study. Inter-rater agreement was evaluated by kappa statistics. Marginal homogeneity was evaluated by the generalized estimating equation (GEE). RESULTS: CXR findings suspected of tuberculosis differed between the four raters. The frequencies of infiltrates and fibrosis/scarring detected on the films significantly differed between the raters from the two countries (P < 0.0001 and P = 0.0082, respectively, by GEE). The definition of findings such as primary cavity, used in the coding systems also affected the degree of agreement. CONCLUSIONS: CXR findings were inconsistent between the raters with different backgrounds. High inter-rater agreement is a component necessary for an optimal CXR coding system, particularly in international studies. An analysis of reading results and a thorough discussion to achieve a consensus would be necessary to achieve further consistency and high quality of reading.

Superiority of nebulized corticosteroids over dry powder inhalers in certain patients with cough variant asthma or cough-predominant asthma.

BACKGROUND: The particle distribution might differ between nebulizer therapy and metered-dose inhaler (MDI) or dry powder inhaler (DPI) therapy because the particles repeatedly enter/re-enter the airways with the nebulizer. Inhaled corticosteroids (ICS) were administered with a nebulizer to assess the benefit of changes in the distribution of particles in patients with cough variant asthma (CVA) and cough-predominant asthma (CPA). METHODS: Patients whose symptoms were not controlled by their current therapy were enrolled. In patients receiving high-dose ICS by MDI or DPI (ICS-MDI/DPI), steroid therapy was switched to 1,320µg/day of nebulized dexamethasone (1,600µg as dexamethasone sodium phosphate) (chronic steroid-independent group). In patients receiving systemic steroids regardless of their ICS-MDI/DPI therapy, nebulized dexamethasone was added and any concurrent ICS-MDI/DPI therapy was halted to detect a steroid-sparing effect (chronic steroid-dependent group). In patients with acute exacerbation of CVA or CPA and persistent symptoms despite systemic corticosteroids, nebulized dexamethasone was added to assess its effect (acute group). RESULTS: Superior symptom control was achieved in 10 out of 12 steroid-independent patients, 3 out of 6 steroid-dependent patients, and all 7 acute patients. CONCLUSIONS: Delivery of ICS via a nebulizer has advantages over ICS-MDI/DPI in some patients with CVA or CPA.

[Tuberculosis screening of foreigners in European, North-American, and Oceanian countries].

PURPOSE: To plan a tuberculosis control program of foreign-born people in Japan, we reviewed the policies of tuberculosis screening on entrance for immigrants and non-immigrant visitors other than refugees and asylum-seekers in European, North American and Oceanic countries. METHODS: Medical literature review and Internet search for the official governmental web sites. RESULTS: In most countries, the main targets of tuberculosis screening programs for foreign-born people are refugees and asylum-seekers. Very few countries have a tuberculosis screening system on entrance for non-immigrant visitors. Such counties include Norway, The Netherlands, UK, Canada, New Zealand and Australia. The USA only screens immigrants who will settle permanently in USA. Screening policies and methods are highly variable, but many of the screening systems are not working well. The effectiveness of mass screening on entrance by chest X-ray, as a tuberculosis control program, is not well analyzed, and the validity of such screening is questionable. CONCLUSION: It is not accurate to think that a tuberculosis-screening program for foreign-born people on entrance to a country is an effective world standard. We must adopt a wider perspective in planning a tuberculosis control program for foreign-born people, including community-based approaches.

[A case of tuberculous pleurisy developing contralateral effusion during anti-tuberculosis chemotherapy].

A 55-year-old woman was admitted to our hospital because of chest pain, fever, and right pleural effusion that was exudative and lymphocyte-dominant with a high level of adenosine deaminase (ADA). Since her blood QuantiFERON-TB 3G test (QFT) was positive, she was diagnosed with tuberculous pleurisy. After initiation of anti-tuberculosis chemotherapy with isoniazid, rifampicin, ethambutol, and pyrazinamide, her symptoms improved. Later, liquid culture of the pleural effusion turned positive for Mycobacterium tuberculosis. On the 18th day of treatment, her chest X-ray and computed tomography exhibited pleural effusion in a moderate amount in the left thorax, with subsiding pleural effusion in the right thorax. Thoracocentesis demonstrated that the left thorax effusion was also exudative and lymphocyte-dominant, with elevated QFT response and high ADA concentration, suggesting tuberculous pleurisy. Mycobacterium tuberculosis was detected in the culture of a left pleural biopsy specimen obtained by thoracoscopy. We assumed that the left pleural effusion was due to paradoxical worsening because (1) on admission no effusion or lung parenchymal lesion was detected in the left hemithorax, (2) on the 14th day of treatment she was afebrile without pleural effusion on both sides, and (3) the bacilli were sensitive to the drugs she had been taking regularly. We performed drainage of the left effusion and continued the same anti-tuberculosis drugs, which led to the elimination of all her symptoms and of the pleural effusion on both sides. In conclusion, paradoxical worsening should be included in the differential diagnosis when contralateral pleural effusion is detected during the treatment of tuberculosis.

[Evaluation of tuberculosis treatment including levofloxacin (LVFX) in cases who could not continue standard regimen].

OBJECTIVE: The purpose of this study was to evaluate tuberculosis treatment including levofloxacin (LVFX) and to investigate the effectiveness of changing drug regimens at our hospital. SUBJECTS AND METHODS: A retrospective study was conducted on 331 patients with tuberculosis admitted to Tokyo National Hospital in 2005. Out of these 331 patients, LVFX was used in 48 (14.5%), 41 of which were initial-treatment cases. We studied why and how LVFX was used and compared bacteriological negative conversion rates between the initial-treatment cases in which the initial standard regimen was changed to regimens including LVFX, and those in which the initial standard regimen was either maintained throughout or modified with drugs other than LVFX. Sputum cultures were examined with Mycobacteria Growth Indicator Tube System (BACTEC MGIT 960). RESULTS: LVFX was used in 41 (13.6%) of 302 initial-treatment cases and in 7 (24.1%) of 29 retreatment cases. Out of the 269 initial-treatment cases starting with the standard regimen, LVFX was later used in 26 cases (9.7%). The reasons for using LVFX were adverse reaction to antituberculosis drugs in 23 cases (88.5%) and resistance to antituberculosis drugs in 3 cases (11.5%). We investigated the bacteriological conversion rate in 228 patients who could be followed up for more than five months. The conversion rates in 105 cases under the standard regimen including PZA (PZA+) were 92.4% in three months, 98.1% in four months, and 100% in five months. The rates in 56 cases under the standard regimen without PZA (PZA-) were 92.9 %, 98.2% and 100%,respectively. The rates of 22 cases under the initial regimen modified with LVFX (LVFX +) were 68.2 %, 95.5% and 100%, respectively. In 45 cases under the initial regimen modified with drugs other than LVFX (LVFX-), the rates were 80.0%, 97.8% and 100%, respectively. CONCLUSION: This study showed that LVFX was an effective drug in terms of the bacteriological conversion rate, without adverse reaction. LVFX is not approved as an antituberculosis drug in Japan, but it is often used in cases of MDR-TB or in situations in which the patients cannot continue treatment with the standard regimen. We hope that LVFX will be approved as an antituberculosis drug as soon as possible in Japan.

Identification of katG mutations associated with high-level isoniazid resistance in Mycobacterium tuberculosis.

Isoniazid (INH) is an effective first-line antituberculosis drug. KatG, a catalase-peroxidase, converts INH to an active form in Mycobacterium tuberculosis, and katG mutations are major causes of INH resistance. In the present study, we sequenced katG of 108 INH-resistant M. tuberculosis clinical isolates. Consequently, 9 novel KatG mutants with a single-amino-acid substitution were found. All of these mutants had significantly lower INH oxidase activities than the wild type, and each mutant showed various levels of activity. Isolates having mutations with relatively low activities showed high-level INH resistance. On the basis of our results and known mutations associated with INH resistance, we developed a new hybridization-based line probe assay for rapid detection of INH-resistant M. tuberculosis isolates.

[A case of cold abscess of the chest wall due to thoracic drainage for tuberculous pleuritis].

A 56-year-old man underwent thoracic drainage for two weeks for tuberculous pleuritis. He was put on antituberculosis chemotherapy with INH (400 mg), RFP (450 mg), and EB (750 mg). Two months later, he developed an elastic hard subcutaneous mass in the area of the previous thoracic drainage. The mass was 10 cm in diameter, warm, reddish and painful. Chest computed tomography (CT) revealed localized and encapsulated empyema in the left thoracic space and a subcutaneous abscess with rim enhancement in the left lateral chest wall. Magnetic resonance imaging (MRI) demonstrated a dumbbell abscess in the subcutaneous tissue communicating with the empyema through the chest wall. A needle aspiration of the subcutaneous abscess had acid-fast bacilli smears of 2+ and tested positive by polymerase chain reaction (PCR) for Mycobacterium tuberculosis. Thus, he was diagnosed with a cold abscess of the chest, with the empyema in the thoracic space draining into the chest wall through the cut for artificial drainage. Continuation of the anti-tuberculosis treatment and the drainage of the empyema with repeated aspiration reduced the subcutaneous mass, and the clinical and radiological course was favorable. Both the smear and culture for acid-fast test became negative. After completion of chemotherapy, there has been no disease recurrence.

[Review of pulmonary Mycobacterium xenopi infection cases: 11 cases of our own and 18 other cases reported in Japan].

OBJECTIVE: To investigate clinical features of patients with pulmonary Mycobacterium xenopi infection treated at our hospital. SUBJECTS AND METHODS: We diagnosed 11 cases of M. xenopi infection at Tokyo National Hospital between 2000 and 2008 and recorded the drug susceptibility, patient characteristics, radiographic findings, treatments given and clinical courses. Eighteen other Japanese cases from the literature were discussed along with our findings. RESULTS AND METHODS: The cases of M. xenopi infection at our hospital consisted of 10 men and 1 woman with a mean age (+/- SD) of 55.1 +/- 19.4 years. Among the patients, 10 were smokers, 4 were heavy drinkers, and 6 had sequelae of pulmonary tuberculosis as an underlying disorder. Four patients had chronic obstructive pulmonary disease and 2 had diabetes mellitus, while there were 2 patients who had no underlying disease. All cases had radiographic opacities, predominantly found in the upper lung region, and cavernous lesions. These findings were demonstrated in both lungs in 5 patients, in the right lung only in 5 patients and in the left lung only in 1 patient. Concurrent aspergillosis was observed in 8 patients. The bacterial isolates from 7 cases were tested for drug sensitivity to levofloxacin (LVFX) and were found to be susceptible. M. xenopi disease was treated in 5 cases with INH+RFP+EB, in 2 cases with INH+RFP+Clarithromycin (CAM), and in 1 case with RFP+EB+CAM. Concurrent aspergillosis was treated with itraconazole in 2 cases. One patient underwent surgery for lung cancer. The duration of treatment was 16.4 +/- 12.8 months (range, 4-36 months). The radiographic findings were improved in 4 cases, deteriorated in 2 and unchanged in 5. M. xenopi was eradicated bacteriologically in 6 cases. The combination of radiographic and bacteriological findings indicated improvement in 3 cases, no change in 6 and deterioration in 2. DISCUSSION: The review of our cases disclosed that medical treatment alone was not sufficient in most cases for the control of clinical M. xenopi infection as reported overseas. Although we did not use LVFX for treatment, LVFX might be recommended for the treatment since all isolates tested proved to be susceptible to LVFX.

[Clinical investigation among elderly patients with tuberculosis].

OBJECTIVES: We discussed the factors which may confuse diagnosis and treatment of tuberculosis (TB) in elderly patients, in order to improve the situation. SUBJECTS AND METHODS: 414 patients who were hospitalized for active tuberculosis in Tokyo National Hospital were divided into three groups according to their ages (in years): less than 65, 65 to 74, and greater than 75. The three groups were compared in terms of performance status (PS), serum albumin level (whether over 3 g/dl or not), underlying diseases, symptoms at onset, sputum smear findings for acid-fast bacilli, presence or absence of cavitary lesion, regimen of treatment, adverse reaction to medications, and treatment outcome. RESULT: The older group had significantly poorer PS (3 or 4), lower albumin level, more complications, a larger proportion of non-respiratory to respiratory symptoms, less cavity formation, less likelihood of continuing to take drugs regularly and higher mortality. It is supposed that these characteristics are mostly due to the aging itself. CONCLUSION: Diagnosing and treating active tuberculosis among elderly people is difficult because of nonspecific and thus confusing findings due to other diseases or aging. Delay in diagnosis and start of treatment makes prognosis of their TB poorer. To improve this situation we should keep a high index to TB and make better use of novel diagnostic technologies. For satisfactory treatment that allows maintenance of a high level of activity of daily life, it is necessary to pay more attention to such aspects as nutrition and rehabilitation and to offer appropriate supports.

[Two cases of tuberculosis after treatment of rheumatoid arthritis with infliximab].

We report two cases of tuberculosis (TB) after treatment with infliximab (IFX) for rheumatoid arthritis (RA). The first case, a 69-year-old woman with RA, developed miliary TB with acute respiratory distress syndrome 21 months after initiation of IFX therapy. Sputum samples revealed smears and cultures positive for Mycobacterium tuberculosis and also positive polymerase chain reaction for TB (PCR-TB); in addition urine samples were smear-negative and culture-positive for TB. She was treated with corticosteroid pulse therapy and anti-tuberculosis drugs, and recovered. The second case, a 51-year-old man with RA, had had contact with a tuberculosis patient four years after initiation of IFX therapy. One year later, he developed pulmonary and pleural tuberculosis. Mycobacterium tuberculosis was detected in the bronchial lavage fluid and pleural effusion (smear-negative and culture- and PCR-TB positive). He clinically improved by treatment with anti-tuberculosis drugs. In both cases, the enzyme-linked immunosorbent spot (ELISPOT) tests revealed positive responses although the QuantiFERON TB-2G tests were not positive. We suggest that the ELISPOT test may be useful as a supportive diagnostic tool for tuberculosis in immunocompromised conditions including RA treated with a tumor necrosis factor-alpha (TNF-alpha) inhibitor.

[Clinical analysis on tuberculosis cases among foreigners in our hospital].

BACKGROUND: Although the incidence rate in Japan has been decreasing since the declaration of tuberculosis emergency in 1999, the reported tuberculosis cases among foreigners have been increasing year by year (from 5.1% in 2000 to 6% in 2003). As the number of foreign residents in Japan has been increasing every year, tuberculosis cases among them are also expected to increase. PURPOSE: The aim of this study is to investigate and clarify clinical features of recent tuberculosis patients among foreigners. OBJECT: Fifty-two cases were analyzed, who were admitted to our hospital because of active tuberculosis from January 2004 to April 2007. RESULTS: Among total 52 cases, male was 29, female 23, and the mean age (SD) of the patients was 31.8 (+/- 8.8) years old. Their mother countries were China, Republic of Korea and so on. The cavitary lesions were found on chest X-ray in 54%, the drug resistant rate was 8.2%, and the treatment completion rate was 92%. DISCUSSION & CONCLUSION: Comparing with reports in the past, almost parameters about tuberculosis control have improved, for example the drug resistant rate was decreased and the treatment completion rate was increased. The promotion of DOTS strategy in Japan might be attributed to the improvement of these parameters. Because more immigrants from the developing countries are expected in near future, not only strengthening current DOTS strategy but also new countermeasures such as QFT-2G and Electronic-Nose Technology should be introduced into tuberculosis control of foreigners living in Japan to decrease tuberculosis incidence and improve treatment outcome by early detection and adherence to treatment.

[Clinical research on multi-drug resistant and extensive drug-resistant tuberculosis in Japan].

PURPOSE: To know the number of patients with MDR-TB and XDR-TB newly diagnosed annually and the number of those with continuously culture-positive in spite of continued treatment. METHODS: To fill the questionnaire sent to all the TB hospitals in Japan and to investigate the number of beds for TB, MDR-TB cases newly admitted to each hospital in 2006 and chronic bacillary cases in spite of continued treatment. RESULT: We sent the questionnaires to all the TB hospitals in Japan and 81% of 270 hospitals replied. As the result, 93 MDR-TB were newly hospitalized (12 cases were with XDR-TB). 76 cases of them were newly diagnosed MDR-TB. Almost after 1 year treatment, patients with XDR-TB showed lower negative conversion rate than other MDR-TB (42.9% vs 63.8%) and higher fatality rate (42.9% vs 7.2%). Excluding above 93 new MDR-TB cases, 103 cases with chronic MDR-TB including 44 cases with XDR-TB had been treated during the observation period, 84 case had been hospitalized and other 19 cases at OPD. DISCUSSION: Since 2000, extensive multi-resistant (XDR) TB has been a global topic. In Japan, nation-wide survey on 2002 showed the ratio of MDR and XDR were 1.9% and 0.6% respectively out of 3122 TB stains investigated. XDR/MDR rate was higher than those in other countries. Our clinical based investigation showed total XDR/MDR rate was 28.6% (56/196) and it was similar to that of previous bacteriological survey in 2002. CONCLUSION: We investigated the number of patients with MDR-TB and XDR-TB newly diagnosed in 2006 and the number of those who were continuously culture-positive. The survey showed that there were 196 patients with MDR-TB, and 56 patients of them (28.6%) were with XDR-TB. Many of them were in the districts of Kinki area and Kanto-Shinetsu area and 70% of them had been treated in the hospitals belonging to the National Hospital Organization.

[Usefulness of bronchofiberscopy for the diagnosis of pulmonary non-tuberculous mycobacteriosis--an analysis mainly on pulmonary M. avium complex disease].

OBJECTIVES: The aim of this study was to evaluate the usefulness of bronchofiberscopy (BFS) in the diagnosis of pulmonary non-tuberculous mycobacteriosis (PNTM). MATERIALS AND METHODS: Among 909 PNTM patients admitted to our hospital during the period from 1995 to 2006, BFS was performed for the diagnosis of PNTM in 107 patients (12%) who had either a negative sputum-smear for acid-fast bacilli (AFB) (n = 100) or from whom it had been impossible to collect sputum (n =7). For these 107 cases, we retrospectively compared and analyzed the findings from specimens obtained by BFS, such as smears, cultures, polymerase-chain reaction (PCR), and transbronchial lung biopsy (TBLB), with clinical, radiological, and sputum examination disease, was also seen in the positive ratios of other nontuberculous mycobacteriosis cases. Type and/or spread of MAC disease on chest radiographs did not relate to positive ratios of BFS obtained specimens. Based on overall BFS findings, including the examination of sputum immediately after BFS, 68 of 92 (74%) patients met the diagnostic criteria of MAC disease. Furthermore, through a combination of positive-TBLB findings and positive-PCR findings of BFS specimens, we were able to obtain an early and strong indication of MAC disease in 17 of 36 (47%) patients. CONCLUSION: Using BFS to obtain various kinds of specimens is a useful tool for the early and definite diagnosis of PNTM/pulmonary MAC disease.

[A patient with Mycobacterium avium lung disease presenting with rapid, progressive and multiple cavity formation, who had been treated rheumatoid arthritis with disease modifying anti-rheumatic drugs (DMARDs)].

An 80-year-old woman presented with rapid, progressive and multiple cavitary lesions in both lungs. Rheumatoid arthritis had been diagnosed and been treated with prednisolone (5 mg/day) and bucillamine since 1996. Due to worsening of arthralgia, methotrexate (6 mg/week) and leflunomide (10 mg/day) had been added to the medication since 2003. In April 2005, her chest radiography revealed multiple cavities and nodules predominantly in both upper lung fields, although she complained of no respiratory symptoms. No pathogenic organisms were found, and the cavitary and nodular shadows were increased rapidly within the next 2 months. Therefore, the patient was referred to our hospital in July 2005. Repeat microbiologic findings of sputum were negative for bacteria and fungi, except for Mycobacterium avium (M. avium). She was given a diagnosis of M. avium lung disease, and it seemed to be associated with her compromised status caused by disease modifying anti-rheumatic drugs (DMARDs). She was then successfully treated with combined chemotherapy employed clarithromycin, rifampicin, ethambutol and streptomycin. So far, rapid and progressive deterioration of non-tuberculous mycobacterial lung disease accompanied with an intake of DMARDs had not been reported in Japan. An increase of M. avium complex lung disease in the elderly is now becoming a problem among respiratory physicians. This case highlights the fact that patients who are scheduled to be given DMARDs, particularly elderly case, should be considered to be at an elevated risk of developing non-tuberculous mycobacterial (NTM) lung disease, and the risk of NTM infection should be excluded before prescribing drugs.

Association of rpoB mutations with rifampicin resistance in Mycobacterium avium.

The susceptibility of clinical isolates of Mycobacterium avium to rifampicin (RIF) was examined. All 32 clinical isolates tested, including 18 from Japan, 13 from Poland and 1 from Thailand, were resistant to RIF (minimum inhibitory concentrations (MICs) > or =32 microg/mL for 17 isolates and 2-16 microg/mL for 15 isolates), whereas the type strain of M. avium ATCC 25291 was susceptible to RIF (MIC < or = 0.03 microg/mL). Mutations in nucleotides 1276-1356 of the rpoB gene, termed the 81 bp core region, are associated with RIF resistance in Mycobacterium tuberculosis. No mutations were found in this region in any of the M. avium clinical isolates tested. However, mutation of G-->A to give a Gly544-->Asp substitution was identified within the rpoB gene downstream of the 81 bp region in all clinical isolates. A RIF-resistant strain (ATCC 25291 Rif(r); MIC> or =32 microg/mL) obtained by culturing the type strain in RIF-containing broth possessed a mutation C-->T to give a His445-->Tyr substitution within the 81 bp region. When the rpoB gene of the ATCC 25291 Rif(r) strain and of a clinical isolate were inserted into Mycobacterium smegmatis, organisms with the ATCC 25291 Rif(r) sequence, but not those with the clinical isolate sequence, showed resistance to RIF. These results suggest that mutations of the 81 bp region of rpoB, as well as factors other than rpoB mutation, confer RIF resistance in M. avium.

[Criteria of hospitalization and discharge for tuberculosis in the western developed countries and comparison with that of Japan].

We studied the criteria of hospitalization and discharge in western developed countries, and compared with the criteria of Japan. For 9 regions of USA, New York, Canada, EU, UK, Germany, France, Spain, and Italy we investigated using inter-net search, Pub-Med and other electrical document search webs, official documents expressing opinion on infectiousness after starting chemotherapy and criteria for discontinuing isolation, hospitalization and discharge. In western developed countries, it is the standard opinion that time interval to lose infectiousness after starting chemotherapy is unknown. In many countries there are still remained the hospitalizations for short-term isolation or secure treatment adherence. In criteria for discontinuing isolation or discharge from hospitals, integrated risk of contact with tuberculosis patients (risk of progression to disease when infected and of severe form of tuberculosis such as drug-resistant cases and disseminated or meningitis) is more important determinant than infectiousness itself of tuberculosis patients. In western developed countries, they did not insist on outpatient treatment but adopted flexible policy for hospitalization. In the USA too, inpatient treatment for early treatment phase is frequently seen, and for necessary cases long-term hospitalization is made. The criteria of Japan were thought to focus too strictly on the infectiousness itself of tuberculosis patients.

[A case of pulmonary tuberculosis complicated with an orthotopic liver transplantation].

The infectious disease is one of the most important complications related to the organ transplantation. Patients using immunosuppressive agents often present atypical tuberculosis and the treatment of such case is far more difficult in some cases due to the liver damage and/or the drug interaction. We report a case of pulmonary tuberculosis in a patient of 60-year-old man using tacrolimus after an orthotopic liver transplantation. He had liver transplanted orthotopically for the long-term history of chronic hepatitis B and subsequent liver failure on January 28, 2004. An abnormal shadow was first detected on his chest X-ray film on October, 2004. He was admitted to our hospital after the smear of the gastric juice showed some acid-fast bacilli and tubercle bacilli were confirmed by polymerase chain reaction (PCR). Tuberculin skin test was positive (erythema 10 x 10) and the computed tomography (CT) scan of his chest revealed a nodular opacity with some smaller nodules scattered around in the right upper lobe. We started four anti-tuberculous drugs other than pyrazinamide (PZA) and rifampicin (RFP), which included isoniazid (INH), ethambutol (EB), streptomycin (SM), levofloxacin (LVFX). The liver enzyme was transiently elevated (AST 123 IU/I, ALT 103 IU/I) but improved after desensitization against INH. The blood concentration of tacrolimus preserved between 5 and 7 ng/ml and there was no need to change the dosage.