ABSTRACT
I. Introduction Advances in our understanding of the pathophysiology of cystic fibrosis (CF) lung disease have resulted in the development of therapies to restore airway surface liquid (1), improve mucociliary clearance (2-4), reduce inflammation (5,6), and control infection (7,8). At the same time, CF newborn screening has been recommended in the United States and other countries (9) and is anticipated to be performed in almost every state in the United States by 2010 (P. M. Farrell, personal communication). These developments will result in a growing population of infants and young children with CF for whom methods to assess disease progression and to serve as outcome measures for clinical trials of new therapeutics will be critical.
