Why screen for cystic fibrosis? A clinician's view

In vitro inhibition of neutrophil elastase activity by inhaled anti-Pseudomonas antibiotics used in cystic fibrosis patients

Background. Inhaled antibiotics are commonly used in the treatment of cystic fibrosis lung disease. A previous study suggested neutrophil elastase activation by colistin in vitro. Here, we investigated direct effects of the commonly used antibiotics colistin and tobramycin on neutrophil elastase activity. Methods. Neutrophil elastase was measured spectrophotometrically. The antibiotics colistin and tobramycin were added in different concentrations with or without the addition of albumin. Results. Generally, neutrophil elastase activity was lower in the absence of albumin compared to its presence. Both antibiotics, colistin and tobramycin, had inhibitory effects on neutrophil elastase activity except for high concentrations of colistin when albumin was absent. Conclusions. Our results suggest inhibitory effects of colistin and tobramycin in vitro. There was a clear dependency of neutrophil elastase measurements on the presence of albumin. Clinical studies are needed to investigate potential direct effects of inhaled antibiotics on neutrophil elastase activity in cystic fibrosis airways.

PGD for all cystic fibrosis carrier couples: novel strategy for preventive medicine and cost analysis

Over 1000 children affected with cystic fibrosis (CF) are born annually in the USA. Since IVF with preimplantation genetic diagnosis (PGD) is an alternative to raising a sick child or to aborting an affected fetus, a cost-benefit analysis was performed for a national IVF-PGD program for preventing CF. The amount spent to deliver healthy children for all CF carrier-couples by IVF-PGD was compared with the average annual and lifetime direct medical costs per CF patient avoided. Treating annually about 4000 CF carrier-couples with IVF-PGD would result in 3715 deliveries of non-affected children at a cost of $57,467 per baby. Because the average annual direct medical cost per CF patient was $63,127 and life expectancy is 37 years, savings would be $2.3 million per patient and $2.2 billion for all new CF patients annually in lifetime treatment costs. Cumulated net saving of an IVF-PGD program for all carrier-couples for 37 years would be $33.3 billion. A total of 618,714 cumulative years of patients suffering because of CF and thousands of abortions could be prevented. A national IVF-PGD program is a highly cost-effective novel modality of preventive medicine and would avoid most births of individuals affected with debilitating genetic disease.

Demographic transition of the Swedish cystic fibrosis community—results of modern care

Assessing the results of modern cystic fibrosis (CF)-care and estimating the future population and its demography is important to evaluate the treatment regimens and to calculate the future needs of health-care resources. This paper updates previous incidence calculations. It assesses the results of modern CF-care in terms of survival and changing demography in Sweden. The incidence of CF in Sweden was calculated as 1/5600 live-births. Of the CF-population alive in 1999, 45% were > or = 18 years old. The mean annual mortality rate since 1991 was 0.9% (+/-0.4) and the median age at death 26 years (range 0-72). Of those born > or = 1991, 95% were estimated to survive their 25th birthday. The incidence of CF in Sweden is low. Modern CF-care in Sweden shows good results. The CF-population is growing rapidly and the adult part of the population will soon be larger than the paediatric. Continuously adapted resources are required to assure the future treatment quality especially for the growing adult CF-population.

[Evaluation of diagnosis and follow-up in screened children with cystic fibrosis in Normandy]

The neonatal screening programme in Normandy (France) allowed the formation of a homogenous cystic fibrosis (CF) cohort of 150 children diagnosed between 1980 and 1997. At the time of this retrospective study, 11 were deceased, out of which nine had meconium ileus (eight deaths after surgery, one at 5 years of age). Sixty children born between 1980 and 1993 in the Basse-Normandie region were followed up during a mean 80 months following similar protocols. The mean age at diagnosis was 41 days (SD = 27 d) for infants without meconium ileus. The occurrence of Pseudomonas aeruginosa (P. aeruginosa) infection and chronic colonization was studied using a monovariate followed by a multivariate analysis including the following variables: sex; meconium ileus; anthropometric data at birth and at diagnosis; pancreatic insufficiency; radiological data (Brasfield score); microbiology data at diagnosis; and genetic data. P. aeruginosa infection appeared earlier in children with pancreatic insufficiency (OR = 2.2; p < 0.05) or with radiological abnormalities (Brasfield score < 21) at diagnosis (OR = 3.9; p < 0.05). Meconium ileus (OR = 5.3; p < 0.01), pancreatic insufficiency (OR = 3.8; p < 0.01) and Brasfield score < 21 at diagnosis (OR = 5.6; p < 0.001) were prognosis factors for early chronic P. aeruginosa colonization. In CF children without meconium ileus, the major risk factor found through multivariate analysis for earlier infection and for earlier chronic colonization by P. aeruginosa was a diagnosis delay > 40 days (respectively OR = 4.6; p < 0.001 and OR = 10.4; p < 0.005). These results must be compared with the lower Brasfield score at diagnosis in infants diagnosed after 40 days of life (p < 0.01).

Neonatal screening for metabolic, endocrine, infectious, and genetic disorders. Current and future directions

There are good reasons to expect that future neonatal screening will expand both to include more disorders and to cover more of the global newborn population. Disorders for which neonatal screening will be given high priority in the health care field in the future are CH and PKU. Screening for CH is likely to expand faster than screening for PKU, especially in the developing world. In the future, screening for CAH will be practiced much more widely than today. Screening for CF is likely to qualify for routine neonatal screening in the future, especially if gene therapy becomes successful. Screening for infectious diseases is an area that is also developing rapidly. Which disorders to screen for neonatally will depend on a number of factors that are unique to each society, such as the prevalence, economy, and ethics. This must be realized when international guidelines are drafted. Technical development, which is of major importance for neonatal screening, includes MS-MS, different DNA techniques, and automation. The expansion of biomedical knowledge in a wide variety of fields will establish new grounds for neonatal screening.