[Clinical comparison of male and female patients with pulmonary disease caused by Mycobacterium avium complex (P-MAC)].

OBJECTIVES: The objective of this study was to clarify clinical feature of Pulmonary Mycobacterium avium complex disease (P-MAC). METHOD: The present study was performed in 120 patients with P-MAC diagnosed during the period from January 2000 to March 2007. We divided P-MAC patients into four groups by the clinical disease type and gender, and retrospectively examined the clinical characteristics. RESULTS: The subjects were 15 male (NB-M) and 71 female (NB-F) patients with nodular bronchiectatic disease (NB), and 24 male (FC-M) and 10 female (FC-F) patients with fibrocavitary disease (FC). The average age was lowest in the NB-F group (58.0 yrs), and highest in the FC-M group (65.8 yrs). There were 17 patients in the FC-M group and only two patients in the FC-F group with a history of smoking. The average body mass index (BMI) was 16.9, with the lowest value in the FC-F group. In the FC-M group, most of the patients had underlying pulmonary disease, whereas in the FC-F group, only four patients had underlying old pulmonary tuberculosis. The average anterior-posterior dimension was 75.2 mm, being lowest in the FC-F group, and more than 90 mm in the other groups. The proportion of refractory cases was lowest in the NB-M group. CONCLUSION: We thought that we were able to clarify characteristics of patients with disease caused by MAC by analyzing the types of the disease separately in men and women.

Clinical factors on cavitary and nodular bronchiectatic types in pulmonary Mycobacterium avium complex disease.

BACKGROUND AND OBJECTIVE: Pulmonary Mycobacterium avium complex (MAC) disease is the most common pulmonary non-tuberculous mycobacteriosis (NTM). The clinical and radiological findings were similar to those of pulmonary tuberculosis, both of which are characterized by upper lobe cavities. On the other hand, the presence of middle and lower field lesions with centrilobular nodules and bronchiectasis has been noted. We analyzed the clinical feature of these two radiologically different types and identified their prognostic factors. METHODS: The clinical, laboratory and radiological findings of 273 cases of MAC disease, newly diagnosed during the recent 7 years periods, were investigated. They were radiologically classified into cavitary (Cav) and nodular bronchiectasis (NB) types at the time of diagnosis. The findings of 44 fatal cases were compared with those of the newly diagnosed cases. RESULTS: A prominent increase in the number of cases was recently found only in females. Low body mass index (BMI) and moderately reduced serum albumin were found at the time of first hospital visit in both newly diagnosed and fatal cases. In the latter, peripheral blood lymphocyte count was slightly decreased, and tuberculin skin test was negative in 57.7% of the cases. Radiologically, Cav type was prevalent in males and NB type in females in the newly diagnosed cases, while in the fatal cases Cav type was frequently found in both males and females. The two radiological patterns did not change during the entire disease course. CONCLUSION: Cav type in females was one of the pathogenetic factors. Deterioration of cell-mediated immunity may underlie MAC disease.

[Overview of respiratory infection caused by nontuberculous mycobacteria].

Recently, the clinical importance of nontuberculous mycobacteria (especially, Mycobacterium avium complex [MAC] respiratory infection) has been increasing. In addition, an official ATS/IDSA statement about diagnosis, treatment, and prevention of nontuberculous mycobacterial diseases has been published in February, 2007. In this review article, essence of this official statement will be introduced. In MAC respiratory infection, (i) primarily fibrocavitary disease, (ii) nodular/bronchiectatic disease, and (iii) hypersensitivity-like disease are identified, and (i) and (ii) are clinically important. Primarily fibrocavitary disease is characterized by cavitary lesions in upper lung fields in elderly subjects, smoking patients, or patients with pneumoconiosis. Nodular/bronchiectatic disease is characterized by centrilobular nodules and diffuse bronchiectases in the right middle lobe and the left lingula in middle-aged women. In addition, disseminated MAC disease in patients with acquired immunodeficiency syndrome should be considered. Further studies concerning transmission route as well as mechanism of MAC disease should be performed.

Mycobacterium avium complex pulmonary disease in immunocompetent patients.

Mycobacterium avium complex is becoming increasingly recognized as one of the most common mycobacterial pathogens in humans. It is rapidly becoming a significant cause of pulmonary disease even in those with an intact immunity. In 1997, the American Thoracic Society published recommendations for the diagnosis and treatment of nontuberculous mycobacteria. On the basis of the authors' clinical experience of the myriad presentations of pulmonary Mycobacterium avium complex disease in an immunocompetent host, a clinical classification is proposed. The current data are summarized, and a practical approach to management of the various pulmonary forms of the disease is provided.

[A clinical study of deceased cases of pulmonary M. Avium complex (MAC) disease--: in contrast with survived cases followed-up for 5 years or longer].

We performed a clinical study of pulmonary M. avium complex (MAC) disease comparing decreased cases and survived cases followed-up for 5 years or longer. The results were as follows: 1. At the time of starting the initial medical treatment for pulmonary MAC disease, the deceased cases were older than the survived cases, and the deceased cases were severe than the survived cases in clinical conditions. The spread of the lesions was more extensive and cavities were more frequently observed in the deceased cases than in the survived cases. 2. We classified the clinical pattern of pulmonary MAC disease into a primary infection type and a secondary infection type. Then, we subclassified the primary infection type into a localized type, which contained a tuberculosis-like type and middle, lingular or other lobar pneumonia type, and a diffuse type. The secondary infection type was more frequent in the deceased cases than in the survived cases, and any middle, lingular or other lobar pneumonia type was not observed in the deceased cases. 3. We classified the mode of progression of pulmonary MAC disease in the deceased cases into a tuberculosis-like progression and a diffuse progression. The tuberculosis-like type and the secondary infection type frequently showed the tuberculosis-like progression and the diffuse type frequently showed the diffuse progression. The patients who showed the tuberculosis-like progression were frequently sputum culture positive for MAC, while all patients showing the diffuse progression were culture negative at the time of death. An interval from the estimated onset of the disease to death was shorter in the tuberculosis-like progression type than in the diffuse progression type.

Biologically distinct subtypes of Mycobacterium avium differ in possession of insertion sequence IS901.

Mycobacterium avium causes disease, principally tuberculosis in immunocompromised individuals. It is the most frequent cause of disseminated infections in AIDS patients in the West. The pathogen is also associated with disease in animals, chiefly birds and livestock, and may be isolated from environmental samples such as soil and water. Analysis of strains of M. avium isolated from clinical, veterinary, and environmental sources for the presence of the mycobacterial insertion sequences IS900 and IS901 demonstrates the specific association of IS901 to animal pathogenic M. avium strains. In contrast, most clinical M. avium strains and all AIDS-derived strains examined so far lacked IS901. Significant differences in the plasmid contents and serotypes of strains with and without IS901 were also found. We therefore suggest that the presence of IS901 divides M. avium into two clearly distinct subtypes with differing host range, virulence, plasmid possession, and serotyping antigens. By using DNA sequence data from IS901 and M. avium DNA, a set of polymerase chain reactions were developed for the specific detection and differentiation of these subtypes.

[Clinical characteristics of the lung diseases due to Mycobacterium avium and Mycobacterium intracellulare classified by DNA probe test].

Clinical characteristics of the lung diseases due to M. avium and M. intracellulare classified by DNA probe test were investigated. Between M. avium and M. intracellulare, there was no significant differences in the samples' backgrounds and the clinical characteristics except for their prognoses. The prognosis of the lung diseases due to M. intracellulare was better than those due to M. avium, and M. avium was revealed to be highly susceptible to Cyclocerine than M. intracellulare. No remarkable difference was found in the susceptibility to other antituberculous drugs.