Hypertonic Saline Inhalation for Mycobacterium Avium Complex Pulmonary Disease

Inclusion Criteria: * International guideline criteria for nodular-bronchiectatic MAC lung disease, i.e. symptomatic, nodular bronchiectatic lesions seen on thorax radiography and ≥2 positive cultures of the same MAC species or one positive culture from a bronchoalveolar lavage; * ≥1 positive MAC sputum cultures must be collected in the previous 4 months; * Signed and dated patient informed consent. Exclusion Criteria: * Fibrocavitary MAC lung disease; * Antimycobacterial treatment in the last 6 months; * Previous MAC lung disease treatment failure, defined as persistent culture positivity despite \>6 months of guideline-recommended treatment; * Current clinical relevant asthma or otherwise bronchial hyperresponsiveness that is judged to be a contra-indication for HSi. * Current HSi use * Former adverse reaction to HSi (note: former HSi use that was stopped due to a lack of clinical improvement is not an exclusion criterium); * Hypertonic saline intolerability during the screening test inhalation * Diagnosis of HIV; * Diagnosis of Cystic fibrosis (CF); * Active pulmonary malignancy (primary or metastatic) or any other malignancy requiring chemotherapy or radiotherapy within 6 months before screening or anticipated during the study period; * Active pulmonary tuberculosis, fungal or nocardial disease requiring treatment * Current use of chronic systemic corticosteroids at doses of 15 mg/day for more than 3 months * Prior lung or other solid organ transplant * Known or suspected current drug or alcohol abuse, that is, in the opinion of the Investigator, sufficient to compromise the safety or cooperation of the patient.