The pathogen
Mycobacterium avium complex (MAC) is the most common cause of nontuberculous mycobacterial
pulmonary disease worldwide. The
decision to initiate long-term
antibiotic treatment is difficult for the
physician due to inconsistent
disease progression and
adverse effects associated with the
antibiotic treatment. The
prognostic factors for the progression of MAC
pulmonary disease are low
body mass index, poor
nutritional status, presence of cavitary lesion(s), extensive
disease, and a positive
acid-fast bacilli smear. A regimen consisting of
macrolides (
clarithromycin or
azithromycin) with
rifampin and
ethambutol has been recommended; this regimen significantly improves the
treatment of MAC
pulmonary disease and should be maintained for at least 12 months after negative
sputum culture conversion. However, the rates of default and
disease recurrence after treatment completion are still high. Moreover,
treatment failure or
macrolide resistance can occur, although in some refractory cases, surgical
lung resection can improve
treatment outcomes. However, surgical resection should be carefully performed in a well-equipped center and be based on a rigorous
risk-benefit
analysis in a multidisciplinary setting. New
therapies, including
clofazimine, inhaled
amikacin, and bedaquiline, have shown promising results for the
treatment of MAC
pulmonary disease, especially in
patients with
treatment failure or
macrolide-resistant MAC
pulmonary disease. However, further evidence of the
efficacy and
safety of these new
treatment regimens is needed. Also, a new
consensus is needed for
treatment outcome definitions as widespread use of these definitions could increase the quality of evidence for the
treatment of MAC
pulmonary disease.