Cystic fibrosis

• On the basis of consensus, (11) the diagnosis of cystic fibrosis (CF) is based on (1) the presence of one or more characteristic phenotypic features of chronic, recurrent sinopulmonary disease, nutritional and gastrointestinal abnormalities, male urogenital abnormalities, and salt depletion syndromes; (2) a family history of CF in a sibling; and (3) a positive newborn screening test result associated with laboratory-demonstrated evidence of cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction, such as abnormal sweat chloride concentration, identification of 2 disease-causing CFTR mutations, or demonstration in vivo of characteristic ion transport abnormalities. • On the basis of consensus, (40) annual oral glucose tolerance tests are recommended for people with CF older than 9 years to screen for CF-related diabetes mellitus. • On the basis of research evidence, (21)(22) the long-term therapies to maintain optimal lung health for children and adults with CF include control of chronic airways infection and inflammation, clearance of mucous secretions, and, where clinically applicable, treatments aimed at the basic CF genetic defect. • On the basis of strong research evidence, (24)(25) treatment with ivacaftor, the first US Food and Drug Administration-approved drug that targets the basic CF genetic defect, resulted in improvements in lung function, weight, quality of life, and sweat chloride levels and reduction in exacerbation frequency in people with CF carrying at least one G551D mutation.