Optimization of performance of Dutch newborn screening for cystic fibrosis.

BACKGROUND: Dutch newborn screening (NBS) for Cystic Fibrosis (CF) introduced in 2011 showed a sensitivity of 90% and a positive predictive value (PPV) of 63%. We describe a study including an optimization phase and evaluation of the modified protocol. METHODS: Dutch protocol consists of four steps: determination of immunoreactive trypsinogen (IRT) and pancreatitis-associated protein (PAP), DNA analysis by INNO-LiPA and extended gene analysis (EGA). For the optimization phase we used results of 556,952 newborns screened between April 2011 and June 2014 to calculate effects of 13 alternative protocols on sensitivity, specificity, PPV, ratios of CF to other diagnoses, and costs. One alternative protocol was selected based on calculated sensitivity, PPV and costs and was implemented on 1st July 2016. In this modified protocol DNA analysis is performed in samples with a combination of IRT ≥60 µg/l and PAP ≥3.0 µg/l, IRT ≥100 µg/l and PAP ≥1.2 µg/l or IRT ≥124 µg/l and PAP not relevant. Results of 599,137 newborns screened between 1st July 2016 and 31st December 2019 were similarly evaluated as in the optimization phase. RESULTS: The modified protocol showed a sensitivity of 95%, PPV of 76%, CF to CF transmembrane conductance regulator-related metabolic syndrome/CF screen positive, inconclusive diagnoses (CRMS/CFSPID) ratio 12/1, CF/CF carrier ratio 4/1. Costs per screened newborn were slightly higher. Eleven children, of whom five with classic CF, would not have been referred with the previous protocol. CONCLUSIONS: The modified protocol results in acceptable sensitivity (95%) and good PPV of 76% with minimal increase in costs.

Cost-effectiveness of newborn screening for cystic fibrosis determined with real-life data.

BACKGROUND: Previous cost-effectiveness studies using data from the literature showed that newborn screening for cystic fibrosis (NBSCF) is a good economic option with positive health effects and longer survival. METHODS: We used primary data to compare cost-effectiveness of four screening strategies for NBSCF, i.e. immunoreactive trypsinogen-testing followed by pancreatitis-associated protein-testing (IRT-PAP), IRT-DNA, IRT-DNA-sequencing, and IRT-PAP-DNA-sequencing, each compared to no-screening. A previously developed decision analysis model for NBSCF was fed with model parameters mainly based on a study evaluating two novel screening strategies among 145,499 newborns in The Netherlands. RESULTS: The four screening strategies had cost-effectiveness ratios varying from €23,600 to €29,200 per life-year gained. IRT-PAP had the most favourable cost-effectiveness ratio. Additional life-years can be gained by IRT-DNA but against higher costs. When treatment costs reduce with 5% due to early diagnosis, screening will lead to financial savings. CONCLUSION: NBSCF is as an economically justifiable public health initiative. Of the four strategies tested IRT-PAP is the most economic and this finding should be included in any decision making model, when considering implementation of newborn screening for CF.

Differences in clinical condition and genotype at time of diagnosis of cystic fibrosis by newborn screening or by symptoms.

BACKGROUND: Early diagnosis through newborn screening (NBS) and early treatment of cystic fibrosis (CF) do lead to better prognosis. In the Netherlands, the median age for a clinical diagnosis is six months, and after newborn screening this is 30 days. It is unknown if being diagnosed at the age of six months or before two months leads to a clinically relevant difference of the clinical condition at the time of diagnosis. AIM: The aim of this study is to assess the differences in clinical parameters at diagnosis between children with CF identified by newborn screening (NBS) or by clinical diagnosis (CD) in the Netherlands. METHODS: From July 1st, 2007 to January 1st, 2012 all newly diagnosed CF patients were reported to the Dutch Paediatric Surveillance Unit (DPSU). All paediatricians received a questionnaire to collect data on mutations and clinical condition at diagnosis. Non-classical CF was excluded from the analysis on clinical condition. RESULTS: 204 new CF diagnoses were reported to the DPSU, 33 were reported twice and three had no CF after further testing. 127 questionnaires were returned (76%); 85 children were diagnosed because of clinical symptoms, 40 after NBS and two because of a positive family history. The median age at diagnosis was 34 weeks for a clinical diagnosis and 3 weeks after NBS. Non-classical CF was more prevalent in the NBS group (6 clinical, 14 NBS), mostly F508del/R117H7T (12). Compared to the NBS group, significantly more patients in the CD group showed failure to thrive, respiratory symptoms, and hospitalizations. 62% of the CD group showed abnormal signs at physical examination compared to 4% of the NBS group. CONCLUSION: At the time of diagnosis infants detected after NBS are in a significantly better condition than after a clinical diagnosis. Growth retardation is already seen when after NBS the diagnosis is confirmed, but NBS leads to a diagnosis before respiratory symptoms have developed.

Parental knowledge reduces long term anxiety induced by false-positive test results after newborn screening for cystic fibrosis.

BACKGROUND: False-positive screening results in newborn screening for cystic fibrosis may lead to parental stress, family relationship problems and a changed perception of the child's health. AIM OF THE STUDY: To evaluate whether parental anxiety induced by a false positive screening result disappears after six months and to assess whether a special program to inform parents prior and during the screening procedure prevents or diminishes parental anxiety. METHODS: Prospective controlled study assessing the long term effects of false-positive test results of newborn screening for cystic fibrosis (NBSCF) on parental anxiety and stress by means of questionnaires sent to parents of 106 infants with a false positive newborn screening test and 318 randomly selected infants with a true negative screening test. Additionally we interviewed 25 parents of the false-positive group. RESULTS: Parents showed negative feelings after being informed about the positive screening test result. After confirmation that their child was healthy and not suffering from CF, most parents felt reassured. After six months no difference in anxiety levels between both groups of parents was found. Well-informed parents in the false positive group experienced less stress. CONCLUSIONS: A positive screening test result induces parental anxiety but false positive test results in NBSCF do not seem to cause long-term anxiety. Well-informed parents show lower stress and anxiety levels.

Paediatrics in Barcelona: highlights from the 2010 ERS Annual Congress.

The aim of this update is to describe the paediatric highlights from the 2010 European Respiratory Society Annual Congress in Barcelona, Spain. Abstracts from the seven groups of the Paediatric Assembly (Respiratory physiology, Asthma and allergy, Cystic fibrosis, Respiratory infection and immunology, Neonatology and paediatric intensive care, Respiratory epidemiology and Bronchology) are presented in the context of the current literature.

Paediatrics in Vienna.

The aim of this article is to describe the paediatric highlights from the 2009 European Respiratory Society Annual Congress in Vienna, Austria. The best abstracts from the seven groups of the Paediatric Assembly (asthma and allergy, respiratory epidemiology, cystic fibrosis, respiratory physiology, respiratory infections and immunology, neonatology and paediatric intensive care, and bronchology) are presented alongside findings from the current literature.

[A Dutch family with the hereditary periodic fever or tumour necrosis factor receptor-associated periodic syndrome (TRAPS)]. / Een nederlandse familie met het erfelijke periodieke koortssyndroom 'tumornecrosisfactor receptor-associated periodic syndrome' (TRAPS).

A 9-month-old girl was referred to the paediatrician because of fever of unknown origin. Since the age of 4 years she had recurrent attacks of muscle, joint and abdominal pain, in addition to periodic fever. Her sister and her mother had similar symptoms. The tumour necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS) was suspected and confirmed by DNA analysis. Several members of the extended family were carriers of the same mutation. In patients with recurrent unexplained periods offever in combination with myalgia, arthralgia and abdominal pain, and in whom these symptoms also occur in members of the family, TRAPS should be considered as the cause. Glucocorticosteroids and etanercept, a TNF-receptor antagonist, may be effective in the treatment of attacks. Early recognition of this syndrome is important because of the risk of developing amyloidosis.

[Young children with serious disorders as a result of late diagnosis of cystic fibrosis]. / Jonge kinderen met ernstige afwijkingen door laat herkende cystische fibrose.

A girl and a boy, who both presented with recurrent respiratory infections from birth, were referred to a paediatrician at the age of 2.5 years: they were diagnosed with cystic fibrosis (CF). The girl died from respiratory insufficiency at the age of 6 years and the boy at the age of 13 years from pulmonary aspiration. A further girl and boy who presented with abnormal faeces and failure to thrive were referred to the paediatrician at the ages of 2.5 months with haematomas and 2 weeks with anaemia respectively, as a result of vitamin deficiencies due to malabsorption. They too had CF. The girl had a brain haemorrhage in the meantime that left her with serious impairments. The boy recovered. A delay in diagnosing CF is not uncommon, as the symptoms of CF are hard to differentiate from those of common childhood diseases. However, this diagnostic delay can result in serious organ damage. Current treatment of CF has a predominantly prophylactic character and aims at maintaining normal growth and nutritional status as well as at preventing or postponing chronic bacterial infection of the lower respiratory tract. This treatment is most effective when it is started before any organ damage has occurred: a state that can only be achieved when patients with CF are identified shortly after birth. Therefore, it is important to add CF-screening to the neonatal screening program.

Influence of neonatal screening and centralized treatment on long-term clinical outcome and survival of CF patients.

After an experimental neonatal screening program for cystic fibrosis (CF) from 1973-1979, a follow-up study took place from 1980-1997. Patients were treated at specialized centres (C) or at local hospitals (non-C). Aims of the study were: 1) to determine whether the previously reported benefits from screening persisted with time and after adjustment for confounding variables; and 2) to investigate whether centre treatment was associated with improved prognosis of CF patients. Prognosis of patients detected by screening (S; n=24) was compared with patients detected clinically, born during (non-S; n=29) and after the screening programme (post-S; n=39). In addition, prognosis was compared between 45 C and 47 non-C patients. Multivariable regression analysis was used to compare survival and mixed-effects model regression analysis was used to compare clinical outcome between patients. The analyses included the variables screening, centre treatment, sex, meconium ileus and genotype. S patients had a significantly smaller decline in forced expiratory volume in one second (FEVI) (difference +2.74% predicted) and significantly lower immunoglobulin-G (IgG) levels (difference -473.69 mg x dL(-1)) than non-S patients until 12 yrs of age. At 12 yrs of age, vital capacity was significantly higher in S patients than in non-S patients (difference +362.79 mL). Survival seemed to be best for S patients compared to both non-S and post-S patients. Post-S patients were significantly heavier (difference in SD weight +0.77), had a significantly smaller decline in FEV1 (difference +2.80% pred) and lower IgG levels (difference -453.04 mg x dL(-1)) than non-S patients until 12 yrs of age. C patients had a significantly improved survival (relative risk (RR) 0.18, 95% confidence interval 0.05-0.57) than non-C patients. Early diagnosis through neonatal screening leads to better preservation of lung function in the long term in cystic fibrosis patients. Management of cystic fibrosis patients in specialized centres improves survival.

Effects of single-dose fluticasone on exercise-induced asthma in asthmatic children: a pilot study.

A single high dose of inhaled corticosteroid (ICS) can increase airway caliber in children with asthma attacks and laryngitis subglottica. Presumably the effect is due to the vasoconstrictive and antiedematous properties of topical steroids. Enlarged vessels have been suggested to play a role in the pathophysiology of exercise-induced bronchial obstruction (EIB). To investigate this, we evaluated the effect of a single high dose of fluticasone propionate (FP) on EIB in asthmatic children. Nine children aged 8-16 years with mild to moderate asthma were included. All children had a history of EIB, which was confirmed by an exercise test. None was taking ICS maintenance therapy. The children inhaled either a single dose of 1 mg FP or placebo on 2 separate days within 7-14 days. After inhalation, airway caliber (FEV(1)) was assessed for 4 hr before exercise. Then an exercise challenge was performed on a treadmill to assess EIB (% fall FEV(1)). A significant increase in FEV(1) was observed 1 hr after inhalation of FP compared to placebo. Response to exercise was expressed as maximal % fall in FEV(1) from baseline (% fall) and as area under the curve (AUC) of the 30-min time/response curve. The % fall FEV(1) after exercise and the AUC were significantly reduced when FP was inhaled compared to placebo inhalation (% fall 9.7% vs. 19.2%, respectively, P = 0.038 and AUC 92.0%.min vs. 205.7%.min, respectively, P = 0.03). There was considerable individual variability in reduction of EIB, with 5 out of 9 children having a clinically significant response. We conclude that a single high dose of inhaled FP has an acute protective effect on the bronchial response to exercise in a substantial proportion of asthmatic children.

Influence of intranasal steroids during the grass pollen season on bronchial responsiveness in children and young adults with asthma and hay fever.

BACKGROUND: It has been reported that intranasal corticosteroids can influence bronchial hyperresponsiveness (BHR) in asthmatic subjects with seasonal rhinitis. The purpose of the present study was to evaluate the effect of intranasal fluticasone propionate and beclomethasone dipropionate on BHR and bronchial calibre (forced expiratory volume in one second, FEV(1)) in children and young adults with seasonal rhinitis and mild asthma during two consecutive grass pollen seasons. METHODS: In the first pollen season 25 patients aged 8-28 years were included in a double blind, placebo controlled study. The active treatment group used fluticasone aqueous spray 200 microgram once daily. In the second pollen season 72 patients aged 8-28 years participated in a double blind, placebo controlled study of a similar design to that of the previous year except that an additional treatment group of patients using beclomethasone 200 microg twice daily was included. FEV(1) was measured before and after three and six weeks of treatment; BHR to methacholine (PD(20)) was measured before and after six weeks of treatment. RESULTS: In the first season the mean (SD) logPD(20) of the patients decreased significantly both in the fluticasone group (from 2.43 (0.8) microgram to 1.86 (0.85) microgram) and in the placebo group (from 2.41 (0.42) microgram to 1.87 (0.78) microgram) without any intergroup difference in the change in logPD(20). In the second pollen season the mean logPD(20) in the fluticasone, beclomethasone, and placebo groups did not change significantly. CONCLUSIONS: Intranasal steroids did not influence BHR during two grass pollen seasons in children and young adults with seasonal rhinitis and mild asthma.

Exercise-induced asthma and cardiovascular fitness in asthmatic children.

BACKGROUND: The role of physical training in the management of children with exercise-induced asthma is controversial. A study was undertaken to determine whether a relationship could be found between the occurrence of exercise-induced asthma and the degree of cardiovascular fitness in asthmatic children. METHODS: Twenty eight children aged 6-13 with mild to moderate asthma and dyspnoea during or after physical exercise were tested. All patients had a basal forced expiratory volume in one second (FEV1) of > 80% predicted. Twelve patients were taking corticosteroid maintenance medication by inhalation and 16 were not. Two exercise tests were performed on a treadmill to assess peak oxygen consumption rate (VO2max) and the percentage decrease in FEV1 after exercise. RESULTS: There was no correlation between the VO2max and the percentage decrease in FEV1. Patients not taking steroids showed a greater fall in FEV1 than those receiving corticosteroid medication (mean fall in FEV1 28.7% versus 6.6%). Four of the 12 children treated with steroids and two of the 16 children not taking steroids had a level of cardiovascular fitness lower than the 5th percentile for healthy Dutch children. CONCLUSION: Normal cardiovascular fitness does not prevent exercise-induced asthma.

Multiple Haemophilus influenzae strains and strain variants coexist in the respiratory tract of patients with cystic fibrosis.

To investigate the epidemiology of nontypeable Haemophilus influenzae in the respiratory tract of cystic fibrosis (CF) patients, H. influenzae isolates from sputum specimens of 40 CF patients were analyzed longitudinally for 2 years. The isolates were characterized by analysis of the major outer membrane protein (MOMP) patterns. MOMP variant H. influenzae strains were discriminated from distinct strains by randomly amplified polymorphic DNA analysis of genomic DNA. Multiple H. influenzae strains and MOMP variant strains were isolated from single sputum specimens of 29 patients. In 22 patients, a distinct H. influenzae strain persisted over time (median persistence, 8 months; range 2-24). In general, the appearance of MOMP variant strains did not coincide with the occurrence of exacerbations.