Minimal change in structural, functional and inflammatory markers of lung disease in newborn screened infants with cystic fibrosis at one year.

BACKGROUND: With the widespread introduction of newborn screening for cystic fibrosis (CF), there has been considerable emphasis on the need to develop objective markers of lung health that can be used during infancy. We hypothesised that in a newborn screened (NBS) UK cohort, evidence of airway inflammation and infection at one year would be associated with adverse structural and functional outcomes at the same age. METHODS: Infants underwent lung function testing, chest CT scan and bronchoscopy with bronchoalveolar lavage (BAL) at 1 year of age when clinically well. Microbiology cultures were also available from routine cough swabs. RESULTS: 65 infants had lung function, CT and BAL. Mean (SD) lung clearance index and forced expiratory volume in 0.5 s z-scores were 0.9(1.2) and -0.6(1.1) respectively; median Brody II CF-CT air trapping score on chest CT =0 (interquartile range 0-1, maximum possible score 27). Infants isolating any significant pathogen by 1 yr of age had higher LCI z-score (mean difference 0.9; 95%CI:0.4-1.4; p = 0.001) and a trend towards higher air trapping scores on CT (p = 0.06). BAL neutrophil elastase was detectable in 23% (10/43) infants in whom BAL supernatant was available. This did not relate to air trapping score on CT. CONCLUSIONS: In this UK NBS cohort at one year of age, lung and airway damage is much milder and associations between inflammation, abnormal physiology and structural changes were at best weak, contrary to our hypothesis and previously published reports. Continued follow-up will clarify longer term implications of these very mild structural, functional and inflammatory changes.

High-frequency audiometry reveals high prevalence of aminoglycoside ototoxicity in children with cystic fibrosis.

BACKGROUND: Intravenous aminoglycoside (IV AG) antibiotics, widely used in patients with cystic fibrosis (CF), are known to have ototoxic complications. Despite this, audiological monitoring is not commonly performed and if performed, uses only standard pure-tone audiometry (PTA). The aim of this study was to investigate ototoxicity in CF children, to determine the most appropriate audiological tests and to identify possible risk factors. METHODS: Auditory assessment was performed in CF children using standard pure tone audiometry (PTA), extended high-frequency (EHF) audiometry and distortion-product otoacoustic emissions (DPOAE). RESULTS: 70 CF children, mean (SD) age 10.7 (3.5) years, were recruited. Of the 63 children who received IV AG, 15 (24%) children had ototoxicity detected by EHF audiometry and DPOAE. Standard PTA only detected ototoxicity in 13 children. Eleven of these children had received at least 10 courses of IV AG courses. A 25 to 85 dBHL hearing loss (mean±SD: 57.5±25.7 dBHL) across all EHF frequencies and a significant drop in DPOAE amplitudes at frequencies 4 to 8 kHz were detected. However, standard PTA detected a significant hearing loss (>20 dBHL) only at 8 kHz in 5 of these 15 children and none in 2 subjects who had significantly elevated EHF thresholds. The number of courses of IV AG received, age and lower lung function were shown to be risk factors for ototoxicity. CONCLUSIONS: CF children who had received at least 10 courses of IV AG had a higher risk of ototoxicity. EHF audiometry identified 2 more children with ototoxicity than standard PTA and depending on facilities available, should be the test of choice for detecting ototoxicity in children with CF receiving IV AG.

Normal hearing in a child with the m.1555A>G mutation despite repeated exposure to aminoglycosides. Has the penetrance of this pharmacogenetic interaction been overestimated?

The mtDNA m.1555A>G mutation causes increased susceptibility to aminoglycoside ototoxicity resulting in significant hearing loss in 100% of reported exposed cases. Genetic and audiological assessments were conducted in a sample of 59 children with cystic fibrosis (CF) undergoing aminoglycoside treatment. Of the two m.1555G patients identified one had severe-profound deafness. Surprisingly, the second m.1555G patient exhibited well-preserved hearing despite repeated exposure. This may be a rare case of intact hearing in an m.1555G individual with aminoglycoside use. Alternatively, its penetrance may have been previously overestimated due to recruitment bias. Further studies are required to determine the true penetrance to inform m.1555A>G genetic testing in similar clinical scenarios.

Preferences for Prenatal Tests for Cystic Fibrosis: A Discrete Choice Experiment to Compare the Views of Adult Patients, Carriers of Cystic Fibrosis and Health Professionals.

As new technologies enable the development of non-invasive prenatal diagnosis (NIPD) for cystic fibrosis (CF), research examining stakeholder views is essential for the preparation of implementation strategies. Here, we compare the views of potential service users with those of health professionals who provide counselling for prenatal tests. A questionnaire incorporating a discrete choice experiment examined preferences for key attributes of NIPD and explored views on NIPD for CF. Adult patients (n = 92) and carriers of CF (n = 50) were recruited from one children's and one adult NHS specialist CF centre. Health professionals (n = 70) were recruited via an e-mail invitation to relevant professional bodies. The key attribute affecting service user testing preferences was no miscarriage risk, while for health professionals, accuracy and early testing were important. The uptake of NIPD by service users was predicted to be high and includes couples that would currently decline invasive testing. Many service users (47%) and health professionals (55.2%) thought the availability of NIPD for CF would increase the pressure to undergo prenatal testing. Most service users (68.5%) thought NIPD for CF should be offered to all pregnant women, whereas more health professionals (68.2%) thought NIPD should be reserved for known carrier couples. The implications for clinical practice are discussed.

The role of endoscopy and biopsy in the management of severe gastrointestinal disease in cystic fibrosis patients.

There is increasing evidence to suggest the presence of chronic inflammation in the gastrointestinal (GI) tract of cystic fibrosis (CF) patients. Some CF patients continue to have very severe gastrointestinal symptoms despite conventional CF treatment. In our center, these patients are managed in a CF gastroenterology clinic, jointly with a pediatric gastroenterologist. A number have required GI endoscopy and biopsy. The aim of our study was to characterize these patients and determine whether endoscopy and biopsy changed their management. We reviewed all the patients seen in the CF gastroenterology clinic from 2004 to 2009, who had GI endoscopies performed. The GI symptoms these patients were experiencing included abdominal pain, nausea and vomiting, rectal bleeding, failure to thrive, loose stools, and constipation. Twelve patients had GI endoscopies with mucosal biopsies performed. The median [interquartile range (IQR)] age at referral to the CF gastroenterology clinic was 4 years [0.9-8]. Their body mass index (BMI) was 15.2 [13.7-15.5]. Twenty-five percent were homozygous delta F508. Two patients had previously had meconium ileus as neonates requiring surgical intervention. One other patient had needed abdominal surgery for intussusception. Ninty-two percent were pancreatic insufficient, 25% were chronically infected with Pseudomonas aeruginosa and 17% were on regularly 3 monthly intravenous antibiotics. Of the 10 patients who were able to perform spirometry, FEV1 was 101% [67-125] predicted. Nine of the 12 patients had evidence of mucosal inflammation in their biopsies, including duodenitis with eosinophilic infiltrate, chronic non-specific inactive gastritis, enteropathy with partial villous atrophy, and non-specific colitis. Immunosuppressive and anti-inflammatory therapies were commenced in these nine patients, including prednisolone, azathioprine, methotrexate, ketotifen, mesalazine, and sulfasalazine as well as the use of parenteral nutrition and elemental feeds. All the patients clinically responded to therapy. Five of the patients commenced on anti-inflammatory therapy had repeat biopsies 1-5 years following commencement of treatment and all showed histological improvement of the mucosal inflammation. GI endoscopy with mucosal biopsy has a significant role to play in the management of CF children with severe GI disease. In our study, it influenced the management in the majority of patients with severe GI symptoms. Furthermore, if GI mucosal inflammation is identified on biopsy, management with immunomodulatory agents may be clinically beneficial.

Aminoglycoside antibiotics cochleotoxicity in paediatric cystic fibrosis (CF) patients: A study using extended high-frequency audiometry and distortion product otoacoustic emissions.

UNLABELLED: Despite known ototoxic effects of aminoglycoside (AG) antibiotics, audiological assessment is not routinely undertaken in UK CF patients. Consequently, the incidence of hearing loss is not well established. OBJECTIVE: To document the incidence of hearing loss in cystic fibrosis (CF) children. DESIGN: Hearing function of 45 children from Great Ormond Street Hospital was assessed using pure-tone audiometry up to 20kHz and DPOAEs up to 8kHz. STUDY SAMPLE: 39/45 of participants had received intravenous (IV) AGs, 23 of which received repeated IV AGs every 3 months. RESULTS: In this high exposure group, 8 (21%) had clear signs of ototoxicity; average 8-20kHz thresholds were elevated by ∼50dB and DPOAE amplitudes were >10dB lower at f2 3.2-6.3 kHz. The remaining 31/39 (79%) of AG exposed patients had normal, even exceptionally good hearing. The 21% incidence of ototoxicity we observed is substantial and higher than previously reported. However, our finding of normal hearing in children with equal AG exposure strongly suggests that other unknown factors, possibly genetic susceptibility, influence this outcome. CONCLUSIONS: We recommend comparable auditory testing in all CF patients with high AG exposures. Genetic analysis may help explain the dichotomy in response to AGs found.

Body composition assessed by the 4-component model and association with lung function in 6-12-y-old children with cystic fibrosis.

BACKGROUND: Malnutrition is an indicator of a poor prognosis in patients with cystic fibrosis (CF). Previous body-composition (BC) studies in children with CF used 2-component models (2CMs) to assess fat mass (FM) and fat-free mass (FFM), but to our knowledge no study has used the gold-standard 4-component model (4CM), which allows for a more accurate evaluation of the nature of both elements. OBJECTIVE: We measured BC by using the 4CM in 6-12-y-old children with CF to 1) compare findings with those of healthy, matched control children and reference data; 2) relate BC to lung spirometry [forced expired volume in 1 s (FEV1)]; and 3) compare findings with those from more commonly used 2CM techniques. DESIGN: One hundred clinically stable children with CF (57% girls) aged 6-12 y were measured by using the 4CM. Children with CF underwent spirometry (FEV1). RESULTS: Girls with CF had significantly less FM than did healthy girls, even after adjustment for height and pubertal status; boys with CF had higher body mass index SD scores than did healthy boys. FM in girls was positively associated with the FEV1 percentage predicted. The 2CM FM was significantly different from the 4CM FM, with differences dependent on sex and condition, although most techniques identified a relation between FM and FEV1 in girls. CONCLUSIONS: Although shorter than healthy children, boys with CF were heavier and had a BC within the normal range; however, girls with CF had lower FM than did healthy girls, and this was associated with poorer lung function. Given the worse prognosis in girls, this finding merits more attention. The reliability of 2CM techniques varied with sex and health status.

Alveolar, but not bronchial nitric oxide production is elevated in cystic fibrosis.

Exhaled nitric oxide (NO) remains a promising non-invasive marker for measuring inflammation in lung diseases. In cystic fibrosis (CF), exhaled NO measured at a single expiratory flow has been found to be normal or low. However, this measure cannot localize the anatomical site of NO production. The aims of this study were to apply a multiple-flow NO analysis to compare alveolar NO concentration and bronchial NO flux in CF children with healthy controls. Twenty-two children with CF and 17 healthy controls had exhaled NO measured at four different expiratory flows to calculate bronchial NO flux and alveolar NO concentration. Median (range) alveolar NO concentration was 2.2 (0.6-5.6) ppb for children with CF and 1.5 (0.4-2.6) ppb for healthy controls. Median (range) bronchial NO flux was 445 (64-1,256) pL/sec for children with CF and 509 (197-1,913) pL/sec for healthy controls. Children with CF had a significantly higher alveolar NO concentration, but no significant difference in bronchial NO flux compared to healthy children. In conclusion, children with CF have increased alveolar NO production, but not bronchial NO flux compared to healthy controls. The distal airway is a major site of inflammation in CF, and measuring alveolar NO may be a marker of distal inflammation in this disease.

Assessing the usefulness of outcomes measured in a cystic fibrosis treatment trial.

Forced expiratory volume in 1s (FEV(1)) is the usual primary outcome variable in clinical trials in cystic fibrosis (CF). Usually, several secondary outcomes are also measured. We assessed which secondary outcomes are likely to give additional clinically useful information about treatment effects, in order to inform the design of future studies. The study was performed as part of a trial comparing daily rhDNase with alternate day rhDNase and hypertonic saline in CF. The primary outcome was FEV(1). Secondary outcomes were forced vital capacity (FVC), forced expiratory flow at 25-75% of forced vital capacity (FEF(25-75)), number of pulmonary exacerbations, weight gain, quality of life (QOL), and exercise tolerance. The usefulness of each secondary outcome was investigated by assessing if the change in that outcome over the treatment period could be predicted from the primary outcome. Change in FEV(1) correlated with changes in FVC (r(2)=0.76, P=0.001), FEF(25-75) (r(2)=0.64, P=0.001), weight (r(2)=0.08, P=0.001), and change in oxygen saturation with exercise (r(2)=0.08, P=0.001). However, it did not correlate with changes in visual analogue score (VAS) with exercise, QOL, nor with the occurrence of pulmonary exacerbations. Only the outcomes QOL and VAS with exercise actually provided additional information to FEV(1) in this study.

The use of human deoxyribonuclease (rhDNase) in the management of cystic fibrosis.

In patients with cystic fibrosis (CF), the poor clearance of airway secretions promotes recurrent cycles of pulmonary infection and inflammation. In recent years, novel drugs have been developed to alter the properties of the secretions in an attempt to aid chest physiotherapy in improving airway clearance. Once-daily nebulised recombinant human deoxyribonuclease (rhDNase; dornase alfa; Pulmozyme) is the most widely used mucoactive therapy in patients with CF. It has been shown to reduce the viscoelasticity of sputum from patients with CF and enhance the clearance of secretions. Clinical trials have shown rhDNase to be a well tolerated treatment that improves pulmonary function and reduces respiratory exacerbations. However, the response to treatment is heterogeneous and only a proportion of patients with CF actually benefit from the treatment. At present, we are unable to predict which patients will benefit from rhDNase. Many CF centers have developed formal n-of-1 trials of treatment to find out who benefits and to justify prescribing the agent. rhDNase is an expensive therapy and is mainly used in patients over the age of 5 years with moderate to severe lung disease. However, studies have shown that rhDNase may be useful in patients with milder lung disease. Comparisons with another mucoactive drug, hypertonic saline, have shown rhDNase to be more effective. Recently, it has been shown that giving rhDNase on an alternate-day basis, rather than daily, is equally effective, potentially reducing costs and treatment time.

Predicting response to rhDNase and hypertonic saline in children with cystic fibrosis.

Daily recombinant human deoxyribonuclease (rhDNase) is an established but expensive treatment in cystic fibrosis (CF). Alternate-day rhDNase and hypertonic saline (HS) represent potential cheaper alternative therapies. However, not all patients improve on treatment. To assess response, many CF centers have developed formal n-of-1 trials of treatment to find out who benefits. Response to daily rhDNase at 3 months has been shown to be a good predictor of response at 1 year. There are no data correlating individual response at a shorter time period with 3-month response. We assessed whether individual responses to daily rhDNase, alternate-day rhDNase, and HS could be predicted from lung function response at 6 weeks, thus shortening the n-of-1 trial, or from baseline patient characteristics, therefore avoiding the need for an n-of-1 trial. In a randomized crossover trial, 48 CF children were allocated consecutively to 12 weeks of once-daily 2.5-mg rhDNase, alternate-day 2.5-mg rhDNase, and twice-daily 5 ml of 7% HS. Forced expiratory volume in 1 sec (FEV1) and forced vital capacity (FVC) were measured at baseline and then at 6 and 12 weeks into each treatment period. Lung function response to the drugs at 6 weeks was highly predictive of response at 3 months. There was some evidence that response to HS was worse in patients with lower baseline lung function. However, there was no association between response to alternate-day or daily rhDNase and baseline characteristics. In conclusion, response to rhDNase and HS at 6 weeks was highly predictive of response at 3 months. For daily and alternate-day rhDNase, at least, the drug needs to be administered for at most 6 weeks initially to assess long-term response to treatment. Response to treatment could not be reliably predicted from baseline characteristics.

Free secretory component from cystic fibrosis sputa displays the cystic fibrosis glycosylation phenotype.

Secretory IgA contributes to humoral defense mechanisms against pathogens targeting mucosal surfaces, and secretory component (SC) fulfills multiple roles in this defense. The aims of this study were to quantify total SC and to analyze the form of free SC in sputa from normal subjects, subjects with asthma, and subjects with cystic fibrosis (CF). Significantly higher levels of SC were detected in CF compared with both other groups. Gel filtration chromatography revealed that SC in CF was relatively degraded. Free SC normally binds interleukin (IL)-8 and inhibits its function. However, in CF sputa, IL-8 binding to intact SC was reduced. Analysis of the total carbohydrate content of free SC signified overglycosylation in CF compared with normal subjects and subjects with asthma. Monosaccharide composition analysis of free SC from CF subjects revealed overfucosylation and undersialylation, in agreement with the reported CF glycosylation phenotype. SC binding to IL-8 did not interfere with the binding of IL-8 to heparin, indicating distinct binding sites on IL-8 for negative regulation of function by SC and heparin. We suggest that defective structure and function of SC contribute to the characteristic sustained inflammatory response in the CF airways.

A cost-effectiveness analysis of rhDNase in children with cystic fibrosis.

OBJECTIVES: This study compared the relative cost-effectiveness of daily recombinant human deoxyribonuclease (rhDNase), with alternate day rhDNase and hypertonic saline (HS) for treating children with cystic fibrosis (CF). METHODS: A randomized controlled trial with a crossover design allocated 40 CF children consecutively to 12 weeks of daily rhDNase, alternate day rhDNase, or HS. The primary outcome measure was forced expiratory volume in 1 second (FEV1), a measure of lung function. All health resource use was prospectively documented for each patient and multiplied by unit costs to give a total health service cost for each 12-week treatment period. The nonparametric bootstrap method was used to present cost-effectiveness acceptability curves and net benefit statistics for each treatment comparison, for various hypothetical levels of the decision maker's ceiling ratio. RESULTS: Compared with HS, there was a 14% improvement in FEV1 for daily rhDNase (95% Cl, 5% to 23%), and a 12% improvement (95% Cl, 2% to 22%) for alternate day rhDNase. For a ceiling ratio of 200 pounds sterling per 1% gain in FEV1, the mean net benefits of daily and alternate day rhDNase compared with HS were 1,158 pounds sterling (95% Cl, -621pounds sterling to 2,842) and 1,188 pounds sterling (95% Cl, -847 to 3,343), respectively; the mean net benefit of daily compared with alternate day rhDNase was -30 pounds sterling (95% Cl, -2,091 pounds sterling to 1,576). CONCLUSIONS: If decision makers are prepared to pay 200 pounds sterling for a 1% gain in FEV1 over a 12-week period, then on average either rhDNase strategy is cost-effective.

Safety and use of sputum induction in children with cystic fibrosis.

We assessed the safety and use of induced sputum (IS) in children with cystic fibrosis (CF). Forty-eight children (19 males) with CF, mean age 12.6 (range, 7.3-17.0) years and median forced expired volume in 1 sec (FEV(1)) 48% (range, 14-77%) predicted were recruited. Patients spontaneously expectorated sputum and then performed sputum induction by inhalation of nebulized 7% hypertonic saline. Samples were sent for bacteriological culture, and for measurement of the following inflammatory mediators: interleukin-8, myeloperoxidase, eosinophil cationic protein, and neutrophil elastase activity. FEV(1) was performed before and after inhalation of hypertonic saline. There was no increase in mediator levels in IS compared to expectorated sputum (ES) samples. Only 3 patients demonstrated significant bronchoconstriction following inhalation of hypertonic saline, by the method used. From the ES samples, Pseudomonas aeruginosa was isolated in 13 patients, Staphylococcus aureus in 7 patients, Stenotrophomonas maltophilia in 1 patient, and both Pseudomonas aeruginosa and Staphylococcus aureus in 5 patients. All these organisms were found in the IS samples. However, in 2 patients whose ES grew no organisms, one patient's IS grew Pseudomonas aeruginosa, and the other patient's IS grew Staphylococcus aureus. In our study, sputum induction was safe, with no proinflammatory effect.

Effects of recombinant human DNase and hypertonic saline on airway inflammation in children with cystic fibrosis.

Recombinant human DNase (rhDNase) is an established treatment in cystic fibrosis (CF), but it may liberate cationic mediators bound to DNA in the airways. An alternative mucolytic therapy is hypertonic saline (HS); however, HS may potentiate neutrophilic inflammation. We compared the effect of rhDNase and HS on cationic proinflammatory mediators in CF sputum. In a randomized, crossover trial, 48 children with CF were allocated consecutively to 12 weeks of once-daily 2.5 mg rhDNase, alternate-day 2.5 mg rhDNase, and twice-daily 7% HS. Sputum levels of total interleukin-8 (IL-8), free IL-8, myeloperoxidase, eosinophil cationic protein, and neutrophil elastase (NE) activity were measured before and after each treatment. The change in mediator levels from baseline with daily rhDNase and HS was not significant; however, with alternate-day rhDNase, there was an increase in free IL-8. When changes in mediator levels with daily rhDNase were compared with alternate-day rhDNase and HS, no significant differences were detected. Only changes in NE activity were associated with changes in lung function. In summary, we were unable to show that rhDNase or HS promote airway inflammation in CF.