[Mycobacterial lung disease in patients with cystic fibrosis--report of three cases].

Mycobacterial lung disease is caused by nontuberculous mycobacteria (NTM), also known as atypical mycobacteria. NTM are widely distributed in the environment, particularly in soil and water. Although generally of low pathogenicity to humans, NTM can affect patients with underlying chronic lung diseases, such as cystic fibrosis, bronchiectasis, pneumoconiosis, or healed tuberculosis. Some patients with cystic fibrosis (CF) have disease progression due to NTM, others can have NTM cultured intermittently from respiratory specimens without a significant decline in lung function. Identifying which patients will worsen from NTM and therefore need treatment remains difficult because of the similarity of symptoms in CF and NTM lung disease. The most common species of NTM isolated in CF patients are Mycobacterium avium complex (MAC) and Mycobacterium abscessus. In this paper, we present three different cases of mycobacterial lung disease in patients with cystic fibrosis.