2008 A Retrospective Study of Clinical, Radiological and Micro- biological Features and Outcomes in Chinese Non-HIV Patients with Pulmonary Mycobacterium Avium Complex Infection
Dr Wong Lan
Department of Medicine, Haven of Hope Hospital
Objectives: To describe the clinical, radiological and microbiological characteristics and outcomes in a cohort of Chinese non-HIV population with Mycobacterium avium complex (MAC) pulmonary disease, and to identify the potential risk factors associated with adverse outcomes.
Design: Retrospective review.
Setting: Chest hospital, Hong Kong.
Patients: All patients with respiratory tract isolates’ culture positive for MAC in the Haven of Hope Hospital, from January 2000 to December 2004.
Measurement and results: There were 69 patients identified, with a mean age of 69 (standard deviation, 13) years and a male to female ratio of 38:31. A significant proportion of patients had underlying lung disease (54%), and past history of pulmonary tuberculosis (42%). Cough was the chief complaint (80%). Small nodules <10mm (76%) and air-space disease (64%) were frequently observed on computed tomography of the thorax and chest radiography respectively. One third of patients had cavitary lung disease. Twenty nine (42%) had smear positive sputum on initial assessment, and 17 (25%) had heavy growth on culture. With a median follow-up duration of 29 months, the mortality rate was 47%. A higher serum albumin level at diagnosis was independently associated with lower mortality (hazard ratio, 0.80; 95% confidence interval [CI], 0.74-0.87; p<0.001). Sputum conversion rate was 67% in the whole group, a prior history of anti-MAC treatment (p=0.016), baseline positive smear status (p=0.010), heavy growth (p=0.002), presence of cavity (p=0.008), ever-smokers (p=0.035), and macrolide-based treatment (p=0.031) were associated with less likelihood of sputum conversion. If both clinical and radiological responses were taken into account, 63% of the patients receiving treatment fulfilled our criteria for treatment success. The absence of baseline positive smear status was independently associated with treatment success (odds ratio 29.4; 95% CI 3.3-250; p<0.001).
Conclusion: The clinical, radiological and microbiological features and outcomes in Hong Kong Chinese were comparable to other studies. The efficacy of current combined chemotherapy for pulmonary MAC disease was suboptimal. For patients with adverse risk factors, more aggressive interventions may be warranted.
