Mycobacterium avium complex pulmonary disease: management options in HIV-negative patients

We present a case series and review of the literature of the management options in non-HIV-infected patients with Mycobacterium avium complex pulmonary disease (MAC-PD) with a focus on treatment failure and drug resistant disease.

Five case histories are presented, depicting various clinical scenarios necessitating different approaches to therapy and highlighting the limitations and complications of these options.

Mycobacterium avium complex (MAC) is well recognized as a significant cause of pulmonary disease in non-HIV infected patients and in those with intact immunity. Isolation of non-tuberculous mycobacteria (NTM) in culture is essential for the diagnosis of NTM lung disease. The typical presentation of MAC lung disease is apical fibrocavitary lung disease in men in their late 40s and early 50s who have a history of cigarette smoking and, frequently, excessive alcohol use. Other presentations of NTM lung disease include nodular bronchiectasis, solitary or multiple pulmonary nodules, and hypersensitivity pneumonitis. When indicated, the standard recommended treatment for most patients is a three-times-weekly regimen of clarithromycin or azithromycin, rifampin, and ethambutol with or without amikacin. Daily therapy is recommended for fibrocavitary disease. Based on published studies, macrolides are the only agents used for treatment of MAC disease for which there is a correlation between in vitro susceptibility and in vivo (clinical) response. Data regarding treatment of macrolide-resistant MAC (MRMAC) and multi-drug resistant MAC (MDRMAC) is sparse. Several drugs have been evaluated in drug-resistant MAC and have potential as effective therapy. Use of multiple drugs to which the isolate is susceptible is preferred to avoid development of future resistance. Surgery in mycobacterial disease is technically difficult, but selected patients with focal disease do benefit from resection of the involved lung.

MAC has protean pulmonary manifestations, especially in those with no recognizable impairments in their immune system. Drug treatment, however, remains difficult with high failure rates and poor long-term sputum conversion. This case series is based on our clinical experience highlighting treatment options and the often unrecognized morbidity and mortality of severe, progressive MAC-PD. It underscores the need for increased awareness of MAC-PD and MDRMAC and the difficulties encountered in their management.