3. Emphasis will be primarily on non CF bronchiectasis for elucidation of mechanisms of infection susceptibility. However, select patients with cystic fibrosis or acquired immune defects (such as HIV) may be studied if relevant host defects are suspected or if needed for comparison purposes or to evaluate and study the management of chronic pathogen associated conditions such as nontuberculous mycobacterial infections or allergic bronchopulmonary aspergillosis.