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Volume 40, Number 4, August 2007

Factors that affect sputum conversion and treatment outcome in patients with Mycobacterium avium-intracellulare complex pulmonary disease

Jung-Jr Ye, Ting-Shu Wu, Ping-Cherng Chiang, Ming-Hsun Lee
Division of Infectious Diseases, Department of Internal Medicine, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan

Received: April 13, 2006    Revised: July 5, 2006    Accepted: July 20, 2006   


Corresponding author:

Dr. Ming-Hsun Lee, Division of Infectious Diseases, Department of Internal Medicine, Chang Gung Memorial Hospital, 5 Fu-Shin St, Kweishan 333, Taoyuan, Taiwan. E-mail: This e-mail address is being protected from spam bots, you need JavaScript enabled to view it



Background and purpose: 

To investigate factors that might affect the sputum conversion and treatment outcome of Mycobacterium avium-intracellulare complex (MAC) pulmonary disease.




This retrospective study reviewed 46 patients diagnosed with MAC pulmonary disease at the Chang Gung Memorial Hospital at Linkou between July 1998 and February 2005. The diagnosis was based on the American Thoracic Society criteria for diagnosis of disease due to non-tuberculous mycobacteria of 1997.




Of the 46 patients reviewed, 30 were men and 16 women, with a mean age of 64.39 years (range, 28-87 years). Thirty one patients had preexisting lung diseases, including history of pulmonary tuberculosis in 23 patients. Follow-up of sputum cultures could be traced in 28 patients, and sputum conversion was found in 17 patients. Of the 28 patients, 9 were treated with anti-MAC drugs for <5 months or with a regimen not containing at least 2 anti-MAC drugs. These treatment regimens were significantly associated with failure of sputum conversion to culture negativity (adjusted odds ratio [OR], 16.83; 95% confidence interval [CI], 1.16-245.06; p=0.039). Eleven of the remaining 19 patients were treated with an anti-MAC regimen containing clarithromycin for >5 months. However, there was no statistically significant association between sputum conversion and clarithromycin-containing anti-MAC regimens (OR, 0.42; 95% CI, 0.08-2.16; p=0.435).




MAC pulmonary disease often occurs in the context of preexisting lung disease, especially pulmonary tuberculosis. Patients tend to be older. Inappropriate treatment might lead to failure of sputum conversion. Treatment with rational combination regimens for at least 5 months could be necessary for sputum conversion.



Key words:

Lung diseases; Mycobacterium avium complex; Mycobacterium avium-intracellulare infection



J Microbiol Immunol Infect. 2007;40:342-348.