A survey of newborn screening for cystic fibrosis in Europe

Clinical changes of patients with cystic fibrosis during transition from pediatric to adult care

PURPOSE

To evaluate the clinical changes of adults with cystic fibrosis (CF) during transition from a pediatric to adult CF center.

METHODS

Data were collected at the time of transfer, 1 year earlier and 1 year later, for all patients in our adult CF center arriving from one of the three pediatric CF centers in Paris between January 2001 and June 2004.

RESULTS

Sixty-three of the 68 patients (transferred at a median age of 21.0 years) were regularly attending this adult CF center after 1 year and one had died. The mean number of outpatient visits increased in the year after transfer (5.7 vs. 3.8 in the year before, p < .001). The occurrence of clinical events and the rate of bronchial colonization did not change. Pseudomonas aeruginosa was found in about 60% of patients at any time. Pulmonary function declined regularly with no statistically significant difference in the rate of decline between the 2 years of follow-up (FEV 1 was 54.7% predicted at transfer). Nutritional status remained stable (mean body mass index was 19.1 kg/m2). The number and duration of oral and i.v. antibiotic courses did not change, but more patients received them at home (p < .001) and self-administered physiotherapy after transfer (p = .001). The proportion of students decreased from 79.3% to 48.1% (p = .02) and the proportion in the workforce increased from 12.7% to 20.4% after transfer.

CONCLUSIONS

Patients with CF remained clinically stable during transition and progressively acquired autonomy.

Pancreatic enzyme replacement therapy for young cystic fibrosis patients

Maldigestion in cystic fibrosis (CF) affects approximately 90% of patients. As soon as pancreatic insufficiency is identified, enzyme supplementation is prescribed even with breast fed infants. A pancreatic enzyme preparation developed particularly for infants, Creon for children (CfC), contains smaller granules to be administered with a dosing spoon (5000 lipase units per scoop).

PATIENTS AND METHODS

In a prospective, randomised, multi-centre study, 40 infants and toddlers received both CfC and Creon 10000 (C10) for two weeks each in a cross-over design. Dosing of pancreatic enzymes was continued as applied before the study. The primary endpoint was the parents' treatment preference. Secondary endpoints included coefficient of fat absorption (CFA), clinical symptoms and safety parameters.

RESULTS

20 parents (51%) from the N=39 intent to treat sample preferred CfC, 9 (23%) preferred C10, and 10 (26%) had no preference The applied doses led to a mean CFA with similar results for both treatments (77.8% vs. 78.7%). Gastrointestinal symptoms were reported on a number of study days, and some children had abnormal results for laboratory parameters of malabsorption. Safety and tolerability of the preparations were good and all these parameters were comparable for both treatments.

CONCLUSION

Those parents who had a preference favoured CfC over C10. Both enzyme preparations improved malabsorption to a similar degree, although the applied dosages could have been too low in some children reflected in a suboptimal CFA. These data support the use of CfC for young patients with cystic fibrosis improving the daily care of this cohort detected mainly now through neonatal screening programmes.

Implementation of the French nationwide cystic fibrosis newborn screening program

OBJECTIVES

To describe optimization of a nationwide newborn screening program for cystic fibrosis (CF) that combines an immunoreactive trypsinogen (IRT) assay and DNA mutation analysis in dried blood samples at day 3.

STUDY DESIGN

Data from regional screening laboratories and CF care centers were centralized and periodically analyzed to allow adaptation, thus limiting the number of false-positive cases.

RESULTS

A total of 2717905 infants were screened between 2002 and 2005. Flow chart protocol was modified twice. First, the IRT d3 cutoff value increased from 60 to 65 microg/L, thus decreasing the percentage of samples requiring mutation analysis from 0.82% to 0.64%. Second, for infants with no mutations using the screening panel, a recall for IRT was performed only if IRT d3 was > 100 microg/L; the percentage of recalls decreased from 0.51% to 0.12%, and the percentage of infants requiring a sweat test decreased from 0.14% to 0.01%. No significant change in the CF detection rate was observed after these 2 modifications. A total of 625 CF cases were detected, and 22 false-negative findings (3.4%) were observed, most of them inevitable, with a low initial IRT.

CONCLUSIONS

The centralized data analysis led to changes in the screening strategy to optimise the newborn screening program.

Prenatal diagnosis of cystic fibrosis: the 18-year experience of Brittany (western France)

OBJECTIVE

This study reports 18 years of experience in prenatal diagnosis (PD) of cystic fibrosis (CF) in a region where CF is frequent and the uptake of PD is common (Brittany, western France).

METHOD

All PDs made over the period 1989-2006 in women living in Brittany were collected.

RESULTS

We recorded 268 PDs made in 1 in 4 risk couples, plus 22 PDs directly made following the sonographic finding of echogenic bowel. Most of the 268 PDs were done in couples already having CF child(ren) (n = 195, 72.8%). Close to one-fifth followed cascade screening (n = 49, 18.3%), which identified 26 new 1 in 4 risk couples among the relatives of CF patients or of carriers identified through newborn screening (NBS). The remaining PDs were mainly made in couples whose 1 in 4 risk was evidenced following the diagnosis of echogenic bowel in a previous pregnancy (n = 22, 8.2%). Although patients' life expectancy has considerably improved, in our population the great majority of couples chose pregnancy termination when PD indicated that the foetus had CF (95.9%).

CONCLUSION

This study describes the distribution of PDs according to the context in which the 1 in 4 risk was discovered and highlights the real decisions of couples as regards pregnancy termination after a positive PD.

The prevalence of cystic fibrosis in the European Union

This study combined a variety of methods to determine the prevalence of cystic fibrosis in the European Union. The results of literature reviews, surveys, and registry analyses revealed a mean prevalence of 0.737/10,000 in the 27 EU countries, which is similar to the value of 0.797 in the United States, and only one outlier, namely the Republic of Ireland at 2.98.

Cystic fibrosis and neonatal screening

The clinical and diagnostic aspects of cystic fibrosis have been extensively reviewed, with an emphasis on neonatal screening. This systematic literature review involved a search for relevant contributions in the PubMed and SciELO databases. The first references to cystic fibrosis date to the Middle Ages. Cystic fibrosis is the most frequent autosomal recessive hereditary disease among Caucasians (1:2,000 to 3,500). More than 1,000 mutations lead to the disease, the most common being "F508, with 70% prevalence among Canadian, Northern European, and American Caucasians and 23 to 55% prevalence among Brazilians. The basic defect is in chloride ion secretion. Cystic fibrosis screening has long been controversial, and after almost three decades, there are few nationwide programs (most are regional or local). However, the U.S. Centers for Disease Control and Prevention (CDC) has concluded that screening for cystic fibrosis is justified. The lack of a specific screening test and the ethnic heterogeneity of the Brazilian population pose challenges for neonatal screening.

Time trends in birth incidence of cystic fibrosis in two European areas: data from newborn screening programs

OBJECTIVE

To determine the incidence of cystic fibrosis (CF) and its time trends over a 16-year period (1990 to 2005) in 2 European regions with a long history of newborn screening (NBS) for CF, and to investigate the impact of some external factors.

STUDY DESIGN

This study focused on data from NBS and prenatal diagnosis (PD) in Brittany (western France) and Veneto/Trentino Alto-Adige (northeastern Italy).

RESULTS

Similar birth incidences of CF were observed in the 2 regions (1/3153 vs 1/3540; P = .245). Time trend analysis using Poisson regression revealed that the birth incidence decreased significantly in the Italian area only (average annual percent change [AAPC] = -4.7%; 95% confidence interval [CI] = -7.3 to -2; P = .0008). The use of PD appeared more common in Brittany, and considering the terminations of CF-affected fetuses, the adjusted incidence was 1/2191 in Brittany and 1/3116 in Veneto/Trentino, corresponding to variations of 30.5% (highly significant; P = .0002) and 12% (not significant; P = .16), respectively. Recording the reason for each PD allowed ready assessment of the affect of various public health policies on incidence. The affect of population mixing also appeared to be relevant in the Italian area.

CONCLUSIONS

This study highlights how the incidence of CF has evolved in 2 European regions that have different attitudes toward PD and immigration policy.

Imparting carrier status results detected by universal newborn screening for sickle cell and cystic fibrosis in England: a qualitative study of current practice and policy challenges

BACKGROUND

Universal newborn screening for early detection of children affected by sickle cell disorders and cystic fibrosis is currently being implemented across England. Parents of infants identified as carriers of these disorders must also be informed of their baby's result. However there is a lack of evidence for most effective practice internationally when doing so. This study describes current or proposed models for imparting this information in practice and explores associated challenges for policy.

METHODS

Thematic analysis of semi-structured interviews with Child Health Coordinators from all English Health Regions.

RESULTS

Diverse methods for imparting carrier results, both within and between regions, and within and between conditions, were being implemented or planned. Models ranged from result by letter to in-person communication during a home visit. Non-specialists were considered the best placed professionals to give results and a similar approach for both conditions was emphasised. While national guidance has influenced choice of models, other factors contributed such as existing service structures and lack of funding. Challenges included uncertainty about guidance specifying face to face notification; how best to balance allaying parental anxiety by using familiar non-specialist health professionals with concerns about practitioner competence; and extent of information parents should be given. Inadequate consideration of resource and service workload was seen as the main policy obstacle. Clarification of existing guidance; more specific protocols to ensure consistent countrywide practice; integration of the two programmes; and 'normalising' carrier status were suggested as improvements.

CONCLUSION

Differing models for communicating carrier results raise concerns about equity and clinical governance. However, this variation provides opportunity for evaluation. Timely and more detailed guidance on protocols with clarification of existing recommendations is needed.

A global perspective on newborn screening for cystic fibrosis

PURPOSE OF REVIEW

Cystic fibrosis screening in newborns is occurring in an increasing number of countries, but protocols vary across regions, borders and continents. This review describes recent advances in the rationale for newborn screening and then suggests solutions to the hurdles that need to be overcome by clinicians to ensure long-term clinical outcomes can be measured robustly whilst retaining the confidence of the funding authorities who have many calls on limited budgets. The review is written to address the concerns of the sceptics.

RECENT FINDINGS

Beneficial evidence for screening for cystic fibrosis in newborns is accumulating and will be highlighted to aid those about to introduce screening for cystic fibrosis in competition with other diseases. Future approaches are described to minimize the amount of DNA-based information held but without compromising screening efficacy. Finally, guidelines for a pilot dataset of information that must be collected on each screened infant will be proposed.

SUMMARY

Standardization of international programs for newborns has not yet been achieved. Progress towards this goal is being made but many differences remain. Solutions to the practical difficulties of implementation of screening for newborns are described to help cystic fibrosis clinicians convince their colleagues of the merits of this practice.

Newborn screening for cystic fibrosis: techniques and strategies

Newborn screening for cystic fibrosis has been carried out for over 25 years, and clinical and cost benefits have been documented. There is still much variation in the methods and strategies adopted. All current screening programmes use a measurement of immunoreactive trypsin as a primary screening test, and in most, a second tier test involves analysing DNA mutations. The choice of DNA mutations depends on the genetic background in the region, and considerations of cost. Using DNA analysis as part of a screening procedure has introduced unwanted carrier detection, and protocols have now been devised in an attempt to avoid this. There are at least seven distinct protocols in use, all of which have different advantages and disadvantages, and no method or strategy will suit every region. Further careful study of performance and costs of various strategies is needed.

Unexpected diagnosis of cystic fibrosis at liver biopsy: a report of four pediatric cases

We report here four cases of pediatric patients in whom the diagnosis of cystic fibrosis was made only after the histological examination of a liver specimen obtained by biopsy (three cases) or at autopsy (one case). There were two boys and two girls, aged 13 months to 7.5 years. None had a personal or familial history suggestive of cystic fibrosis. One patient, presenting with myocardial lesion and hepatomegaly, died of heart failure; at autopsy, the liver showed a typical aspect of focal biliary cirrhosis. In the three other cases, liver disease was the only manifestation of cystic fibrosis at the time of diagnosis. Liver biopsy examination showed focal biliary cirrhosis in one case and massive steatosis in two. In all four cases, the diagnosis was confirmed by the existence of known pathogenic mutations in the CFTR gene. The evolution was variable; one patient had progressive liver disease with severe portal hypertension after 7 years; another one had lung complications after 1 year. In conclusion, our experience recalls that the diagnosis of cystic fibrosis must be considered in children presenting with unexplained liver disease; its confirmation by molecular techniques makes it possible to set up an appropriate follow-up.

Cystic Fibrosis and Formes Frustes of CFTR-Related Disease

Cystic fibrosis (CF) is the commonest genetic cause of bronchiectasis in the Caucasian population. Since identification of the putative gene in 1989, the molecular basis of the condition has become clearer with characterisation of the unique pathophysiology. The small airways are the primary site of lung disease, with an intense but localised inflammatory picture, dominated by neutrophils. The clinical heterogeneity is explained to some degree by the distinct molecular consequences of the many mutations that have been recognised to affect the CF transmembrane conductance regulator (CFTR) gene; however other genes appear to modify the phenotype as well as environmental exposure. It has become increasingly apparent that certain conditions may result from CFTR dysfunction without fulfilling diagnostic criteria for CF. In some cases this may result in single organ disease for which the term CF (or CFTR)-related disease has been advocated. Congenital bilateral absence of the vas deferens is the most clearly characterised of these. In other cases where a mild CF phenotype is apparent, atypical CF is probably a better term. It remains unclear whether carrier status predisposes to certain conditions such as chronic rhinosinusitis or pancreatitis.