This comprehensive State of the Art review summarizes the current published knowledge base regarding the pathophysiology and microbiology of pulmonary disease in cystic fibrosis (CF). The molecular basis of CF lung disease including the impact of defective cystic fibrosis transmembrane regulator (CFTR) protein function on airway physiology, mucociliary clearance, and establishment of Pseudomonas aeruginosa infection is described. An extensive review of the microbiology of CF lung disease with particular reference to infection with P. aeruginosa is provided. Other pathogens commonly associated with CF lung disease including Staphylococcal aureus, Burkholderia cepacia, Stenotrophomonas maltophilia, Achromobacter xylosoxidans and atypical mycobacteria are also described. Clinical presentation and assessment of CF lung disease including diagnostic microbiology and other measures of pulmonary health are reviewed. Current recommendations for management of CF lung disease are provided. An extensive review of antipseudomonal therapies in the settings of treatment for early P. aeruginosa infection, maintenance for patients with chronic P. aeruginosa infection, and treatment of exacerbation in pulmonary symptoms, as well as antibiotic therapies for other CF respiratory pathogens, are included. In addition, the article discusses infection control policies, therapies to optimize airway clearance and reduce inflammation, and potential future therapies.

We conducted a registry-based study to determine prognostic indicators of 8-year mortality and morbidity in young children with cystic fibrosis (CF). Patients ages 1-5 years from the 1990 U.S. Cystic Fibrosis Foundation (CFF) National Patient Registry served as the study cohort (N = 3,323). Registry data provided information on baseline characteristics in 1990, 8-year mortality, and clinical outcomes in 1998.P. aeruginosa respiratory infection was found to be a major predictor of morbidity and mortality. The 8-year risk of death was 2.6 times higher in patients who had respiratory cultures positive for P. aeruginosa in 1990 (95% confidence interval 1.6, 4.1) than in children without P. aeruginosa in their respiratory cultures. Culture-positive patients in 1990 also had a significantly lower percent predicted forced expiratory volume in 1 sec (FEV(1)) and weight percentile at follow-up, and they had an increased risk of continued P. aeruginosa respiratory infection and hospitalization for acute respiratory exacerbation in 1998. Among the other predictors of increased morbidity and mortality were lower baseline weight percentiles and number of CF-related hospitalizations during the baseline year.These findings confirm reports from previous smaller studies of outcomes among young children with CF, and highlight the potential to decrease the morbidity and mortality of young patients with CF through early intervention.

Pseudomonas aeruginosa lung infection is an important cause of morbidity and mortality in cystic fibrosis (CF). Longitudinal assessment of the phenotypic changes in P. aeruginosa isolated from young children with CF is lacking. This study investigated genotypic and phenotypic changes in P. aeruginosa from oropharynx (OP) and bronchoalveolar lavage fluid (BALF) in a cohort of 40 CF patients during the first 3 years of life; antibody response was also examined. A high degree of genotypic variability was identified, and each patient had unique genotypes. Early isolates had a phenotype distinct from those of usual CF isolates: generally nonmucoid and antibiotic susceptible. Genotype and phenotype correlated between OP and BALF isolates. As determined by culture, 72.5% of patients demonstrated P. aeruginosa during their first 3 years. On the basis of combined culture and serologic results, 97.5% of patients had evidence of infection by age 3 years, which suggests that P. aeruginosa infection occurs early in CF and may be intermittent or undetectable by culture.