Q; 53 year old female with chronic cough but no other major past medical or substance abuse history and otherwise healthy is admitted to ICU with possible pneumonia requiring Non-Invasive-Postive-Pressure-Ventilation (NIPPV). Sputum culture grew M. avium complex (MAC). 
What underlying disease should be suspected?


 Answer: Interstitial Lung Disease (ILD)

MAC pulmonary disease is usually common in malnourished, alcoholics, smokers  or with underlying chronic obstructive lung disease (COPD), prior bronchiectasis, and cystic fibrosis.

Other major group of patient prone to get MAC are nonsmoking women over age 50 who have underlying interstitial disease.


Reference:

Prince DS, Peterson DD, Steiner RM, et al. Infection with Mycobacterium avium complex in patients without predisposing conditions. N Engl J Med 1989; 321:863.