Early detection of lung disease and its association with the nutritional status, genetic background and life events in patients with cystic fibrosis.

Progression of lung disease is the most prominent cause of morbidity and death in patients with cystic fibrosis (CF), but the severity of lung disease and the rate of lung function decline are highly variable. An attempt was made to define accurate estimates of disease progression in these patients early diagnosed and prospectively evaluated until 10 years of age. The primary question to ask was whether functional abnormalities detected already in infancy are associated with functional derangements later on in life, and may be useful as parameters of prognostic value. Early diagnosis of CF can best be achieved by screening of mutation by new techniques (buccal cell brushing) in infants, even when the sweat test or accurate blood sampling is not available. Moreover, in infants lung function can be assessed by infant whole-body plethysmography enabling the study of the interrelationship with delayed weight gain and growth retardation, as well as the associations with the most common disease-causing mutations. Out of a cohort of 80 infants (39 males, 41 females) with CF a follow-up study was started with 50 CF infants diagnosed during infancy (mean age 4.6 +/- 4.0 months; range 0.1-12.7 months) and prospectively evaluated at 6-month intervals during the first 2 years of life. Moreover, in 32 CF children out of this cohort, follow-up was continued until 10 years of age. Differences were encountered with respect to the different events occurring during the first years of life, especially the onset of chronic colonization with Pseudomonas aeruginosa. The association between infant lung function and specific mutations (DeltaF508 homozygotes, frameshift DeltaF508/3905insT compound heterozygotes and nonsense DeltaF508/R553X compound heterozygotes) furthermore revealed that differences in lung function within the genetic groups are mainly related to the degree of pulmonary hyperinflation. Pulmonary hyperinflation was also associated with the degree of impaired nutritional status. An association between impaired gas exchange characteristics at 10 years of age and the degree of pulmonary hyperinflation during infancy finally demonstrates that by early mutation screening, lung function testing and assessment of the nutritional status predictors of disease progression later on in life can be defined. Therefore, preventive therapeutic measures should primarily be based on such prognostic factors.