Urinary metabolomics reveals unique metabolic signatures in infants with cystic fibrosis.

BACKGROUND: Biologic pathways and metabolic mechanisms underpinning early systemic disease in cystic fibrosis (CF) are poorly understood. The Baby Observational and Nutrition Study (BONUS) was a prospective multi-center study of infants with CF with a primary aim to examine the current state of nutrition in the first year of life. Its secondary aim was to prospectively explore concurrent nutritional, metabolic, respiratory, infectious, and inflammatory characteristics associated with early CF anthropometric measurements. We report here metabolomics differences within the urine of these infants as compared to infants without CF. METHODS: Urine metabolomics was performed for 85 infants with predefined clinical phenotypes at approximately one year of age enrolled in BONUS via Ultrahigh Performance Liquid Chromatography-Tandem Mass Spectroscopy (UPLC-MS/MS). Samples were stratified by disease status (non-CF controls (n = 22); CF (n = 63, All-CF)) and CF clinical phenotype: respiratory hospitalization (CF Resp, n = 22), low length (CF LL, n = 23), and low weight (CF LW, n = 15). RESULTS: Global urine metabolomics profiles in CF were heterogeneous, however there were distinct metabolic differences between the CF and non-CF groups. Top pathways altered in CF included tRNA charging and methionine degradation. ADCYAP1 and huntingtin were identified as predicted unique regulators of altered metabolic pathways in CF compared to non-CF. Infants with CF displayed alterations in metabolites associated with bile acid homeostasis, pentose sugars, and vitamins. CONCLUSIONS: Predicted metabolic pathways and regulators were identified in CF infants compared to non-CF, but metabolic profiles were unable to discriminate between CF phenotypes. Targeted metabolomics provides an opportunity for further understanding of early CF disease. TRIAL REGISTRATION: United States ClinicalTrials.Gov registry NCT01424696 (clinicaltrials.gov).

Repeat administration of an adenovirus vector encoding cystic fibrosis transmembrane conductance regulator to the nasal epithelium of patients with cystic fibrosis.

Cystic fibrosis (CF) is a common autosomal recessive disease caused by mutations in the CF transmembrane conductance regulator gene. Recombinant adenoviruses have shown promise as vectors for transfer of CF transmembrane conductance regulator cDNA to airway epithelia and correction of the Cl- transport defect. However, because adenovirus-mediated gene transfer is transient, use of adenovirus as a vector for treatment of CF would require repeated administration. Therefore, we evaluated repeat administration of an adenovirus vector to the nasal epithelium of patients with CF with five escalating doses of up to 10(10) infectious units. There were no detectable adverse affects. All subjects were initially seropositive but developed additional humoral immune responses. The vector partially corrected the defect in airway epithelial Cl- transport in some subjects, although there was variability between subjects and there was less correction with subsequent administration, perhaps because the immune response limited gene transfer. Future work must focus on vectors with increased efficiency and with the ability to evade host defenses.

A phase I study of aerosolized administration of tgAAVCF to cystic fibrosis subjects with mild lung disease.

Cystic fibrosis (CF) is one of the most common autosomal recessive disorders in North America, leading to significant morbidity and early mortality. The defect in the cystic fibrosis transmembrane conductance regulator protein (CFTR) function can be corrected in vitro by gene replacement with a wild-type gene. A Phase I, single administration, dose escalation trial was designed and executed to assess safety and delivery of tgAAVCF, an adeno-associated virus (AAV) vector encoding the human CFTR cDNA, by nebulization to the lungs of CF subjects. Four cohorts of three subjects each were administered increasing doses of the study agent, beginning with 10(10) DNase-resistant particles (DRP) and escalating in log increments up to 10(13) DRP. Sequential bronchoscopies were performed to gather analytical samples throughout the study. All 12 subjects completed the study. There were a total of 242 adverse events (AEs), six of which were defined as serious and three of which were defined as possibly being related to the study drug. A clear dose-response relationship was observed in vector gene transfer. A maximum of 0.6 and 0.1 vector copies per brushed cell were observed 14 days and 30 days, respectively, following nebulization of 10(13) DRP tgAAVCF, and this declined to nearly undetectable levels by day 90. Vector gene transfer was evenly distributed throughout the fourth airway generation following single-dose administration. RNA-specific PCR did not detect vector-derived mRNA. This Phase I trial shows that aerosolized tgAAVCF is safe and widely delivered to the proximal airways of CF subjects by nebulization.

The cystic fibrosis therapeutics development network (CF TDN): a paradigm of a clinical trials network for genetic and orphan diseases.

Clinical trials have become critical to the advancement of medical science and to the evolution of patient care in medicine. The science of clinical research has advanced from early studies in which treatment was assessed without controls to sophisticated multinational collaborative randomized, double-blind, placebo controlled trials of therapeutic interventions. To facilitate the advancement of clinical research, clinical trials networks have been developed to conduct multicenter studies. This review describes the history of clinical trials, clinical trials networks, and the goals of such networks in the United States. The Cystic Fibrosis Therapeutics Development Network, a network that represents the paradigm for genetic and orphan diseases, is described in detail. This network has been extremely successful in its first 3.5 years of existence conducting 18 different clinical trials in patients with Cystic Fibrosis. Unique aspects of the network include the use of internet applications for study conduct and communication, the development of statistical methodology to enhance the efficiency of clinical trial design, the development of outcome measures specific to Cystic Fibrosis, and the development of infrastructure necessary for expediting protocol development. In the current environment, clinical research faces significant challenges related to ensuring the safe and ethical conduct of clinical research while promoting fast and efficient clinical trials. To succeed and move forward to provide treatments and find cures for diseases, clinical trials networks must continue to evolve. The Cystic Fibrosis Therapeutics Development Network represents a network that has met this challenge and will continue to provide a venue for the safe and efficient conduct of clinical trials in Cystic Fibrosis.

Nutritional assessment and management in cystic fibrosis: a consensus report. The Consensus Committee.

This report is a summary of a meeting convened by the Cystic Fibrosis Foundation to develop a consensus among nutrition specialists and cystic fibrosis care givers regarding optimal nutritional management of patients with cystic fibrosis. The first section of the report provides a rationale for emphasizing nutritional management of this genetic disorder. The multiple factors causing malnutrition and a negative energy balance are outlined. The second section provides guidelines for routine assessment of nutrition in these patients. Five categories of nutritional status are defined based on ideal weight for height, age, and gender. These categories are used to formulate a graded response for nutritional intervention. Recommendations are provided for routine dietary supplements, vitamin supplements, and pancreatic enzyme replacement. The primary aim of this report is to educate clinicians as to the importance of frequent assessments and early intervention.

Use of bacterial antigen detection in the diagnosis of pediatric lower respiratory tract infections.

Two immunochemical methods were used to identify Haemophilus influenzae and Streptococcus pneumoniae capsular antigens in the urine and serum of 162 children with acute lower respiratory tract infection. These methods were compared with standard bacterial blood culture. Viral and mycoplasma cultures of respiratory secretions were obtained simultaneously to determine the frequency of antigenuria at the time of nonbacterial acute lower respiratory tract infection. Urine from groups of well children and children with acute otitis media was tested for capsular antigens to determine the incidence of antigenuria. Antigenuria was found in 24% of children 2 months to 18 years of age with acute lower respiratory tract infection compared with a 2% incidence of bacteremia. Antigenuria was found in 4% of asymptomatic children and 16% of children with acute otitis media. One third of children with symptoms of acute lower respiratory tract infection and viral isolates from the oropharynx had bacterial antigenuria. The sixfold increase in frequency of bacterial antigenuria in children at the time of lower respiratory symptoms suggests that bacterial acute lower respiratory tract infection may be more common than identified by traditional culture techniques. Because bacterial antigen may come from other sites such as the middle ear, further studies are needed to determine the role of antigen detection in the diagnosis of pediatric acute lower respiratory tract infection.

A comparison of peak sputum tobramycin concentration in patients with cystic fibrosis using jet and ultrasonic nebulizer systems. Aerosolized Tobramycin Study Group.

STUDY OBJECTIVE: To determine whether adequate concentrations of a new formulation of tobramycin could be delivered to the lower respiratory tract of patients with cystic fibrosis (CF) using a jet nebulizer delivery system. DESIGN: A multicenter, open-label, randomized, crossover study. SETTING: Ten tertiary care, university-affiliated, teaching hospitals in the United States. PATIENTS AND CONTROL SUBJECTS: Sixty-eight patients recruited from 10 CF Foundation centers and who were at least 8 years of age, had a diagnosis of CF, and expectorated daily sputum. No control subjects enrolled. INTERVENTIONS: Each patient received one administration of aerosolized tobramycin from each of the three nebulizer systems in random order. Each administration was separated by a minimum of 48 h. The two jet nebulizer systems tested were the Sidestream (Medic-Aid; Sussex, UK), and the Pari LC (Pari Respiratory Equipment; Richmond, Va), with a DeVilbiss Pulmoaide compressor (DeVilbiss Health Care; Somerset, Pa), both administering 300 mg tobramycin in 5 mL of 1/4 normal saline solution (NS). Patients were also administered 600 mg tobramycin in 30 mL of 1/2 NS with the UltraNeb 99/100 (DeVilbiss). MEASUREMENTS: Sputum and serum tobramycin concentration and pulmonary function were monitored. An adequate peak sputum tobramycin concentration was defined as > 128 microg/g sputum at any of three time points (10, 60, or 120 min) after completion of treatments. RESULTS: The peak tobramycin concentrations in expectorated sputum were 687+/-663 microg/g (mean+/-SD) with the Pari LC and 489+/-402 microg/g with the Sidestream. Adequate peak sputum tobramycin concentration was achieved in 93% of the patients with the Sidestream, and in 87% of the patients with the Pari LC. Peak sputum concentrations were found to be substantially higher when patients received tobramycin administered with the UltraNeb 99/100, 1,498+/-1,331 microg/g with 30% of patients having levels exceeding 2,000 microg/g. Serum tobramycin concentrations were < or = 4 microg/mL for all patients following administration with each nebulizer. CONCLUSIONS: Adequately high sputum tobramycin concentrations were documented in sputum in > 85% of patients following the administration of 300 mg/5 mL formulation of tobramycin aerosolized by the two jet nebulizer delivery systems, Sidestream and Pari LC. The single tobramycin administration delivered by these two systems is well-tolerated.

Effects of repetitive use and cleaning techniques of disposable jet nebulizers on aerosol generation.

STUDY OBJECTIVE: Patients with cystic fibrosis use disposable jet nebulizers for the self-administration of antibiotics, DNase, and bronchodilators several times per day. Most patients elect to reuse their disposable nebulizers. The purpose of this study was to determine if significant changes in particle size distribution or output (mL/min) occurred with reuse. DESIGN: In vitro studies were performed using four disposable models and one durable jet nebulizer for up to 100 runs; measurements of particle size and output were obtained at 10 run intervals, using saline solution alone, tobramycin, gentamicin, or a mixture of albuterol and cromolyn. Particle size determinations were made with a laser diffraction analyzer. RESULTS: There was no significant difference between the baseline performance of the four disposable models and the durable Pari LC, when measuring particle size distribution of the aerosol; the Pari LC had an output rate two to three times higher than the four disposable models. For each of the four solutes tested, there was no clinically significant change in performance for up to 100 cycles, when the nebulizers were properly cleaned between uses. Unwashed units containing tobramycin started to fail by 40 runs. CONCLUSIONS: When properly maintained, there was no trend of deterioration of performance with repeated use of disposable nebulizers. Microbial contamination was not addressed in this study and must be considered prior to recommendations for the reuse of disposable nebulizers.

Safety of aerosol tobramycin administration for 3 months to patients with cystic fibrosis.

To determine the potential toxicity of prolonged aerosol tobramycin administration, 22 patients with cystic fibrosis were monitored while receiving inhaled tobramycin three times a day for 12 weeks. Prior to, four times during administration and approximately 6 weeks after discontinuation of treatment, we assessed pulmonary function, weight, height, body temperature, eighth cranial nerve function, serum creatinine, blood urea nitrogen, urinary creatinine clearance, plasma iothalamate clearance, urinary beta-2 microglobulin concentration, and Pseudomonas aeruginosa density in sputum. There was no detectable laboratory evidence of nephrotoxicity. Neither a decrease in auditory acuity (range 250-20,000 Hz) nor vestibular dysfunction was detected. Pulmonary function tests significantly improved during the first month in all subjects (P less than 0.05) but returned to enrollment values by the end of the 12th week of administration of tobramycin aerosol. Sputum P. aeruginosa density initially decreased from a mean of 10(7) cfu/gm to a mean of 10(4) cfu/gm after 2 weeks of aerosol tobramycin administration and remained significantly below the enrollment value throughout. Coincident with the reduced bacterial density, a reduction in cough frequency and sputum production, as well as a weight gain was observed. Seventy-three percent of the patients with sputum P. aeruginosa isolates susceptible to tobramycin on enrollment yielded resistant organisms during aerosol administration. However, 1 year later all sputum P. aeruginosa isolates obtained from patients were susceptible to tobramycin. We conclude that thrice daily aerosol tobramycin administration for 3 months is not associated with detectable eighth cranial nerve or renal toxicity. Transient emergence of tobramycin resistant P. aeruginosa may occur.

Early pulmonary infection, inflammation, and clinical outcomes in infants with cystic fibrosis.

A thorough understanding of the early natural history of cystic fibrosis (CF) lung disease is critical for the development of effective interventions in the youngest patients. We assessed the evolution of pulmonary infection, inflammation, and clinical course among 40 infants over a 2-year period through annual bronchoalveolar lavage (BAL) for culture and measurements of pro- and anti-inflammatory cytokines, semiannual infant pulmonary function testing, and quarterly clinical evaluations. Both the prevalence of CF pathogens and their density in BAL fluid increased with age. Infants had neutrophilic lower airway inflammation and elevated IL-8 concentrations independent of whether CF pathogens were recovered. Total leukocyte and neutrophil densities and IL-8 concentrations increased with density of CF pathogens in BAL fluid, whether the isolated organism was P. aeruginosa or another pathogen. IL-10 concentrations were similar in CF subjects and non-CF historical controls. Infants generally had suboptimal growth (low weight and height percentiles) and obstructive lung disease (decreased expiratory flows and air trapping). Subjects from whom CF pathogens were isolated at > 10(5) cfu/mL had the worst air trapping and lowest Brasfield chest X-ray scores. Our findings provide a foundation for future studies of early intervention in CF lung disease, including antimicrobial and anti-inflammatory therapy.

Nutritional effects of long-term gastrostomy feedings in children with cystic fibrosis.

OBJECTIVE: To analyze the long-term nutritional effects of supplemental gastrostomy feedings in undernourished patients with cystic fibrosis. DESIGN: Longitudinal, retrospective assessment of anthropometric measures before and for up to 4 years after gastrostomy. SUBJECTS/SETTING: All patients at a large cystic fibrosis care center who underwent gastrostomy between 1980 and 1993 when they were at least 1 year old and were followed up for a minimum of 1 year after gastrostomy. STATISTICAL ANALYSES PERFORMED: The Mann-Whitney U test was used to compare anthropometric values measured during 4 postgastrostomy time intervals with values measured during the year preceding gastrostomy. RESULTS: The 21 patients ranged in age from 1.1 to 20.8 years (median age = 7.4 years). They had mild to moderate malnutrition at the time of gastrostomy. Patients were followed up for a mean of 39 months after gastrostomy. Supplemental feedings were associated with significant improvements in weight and height percentiles for age, and in weight as a percentage of ideal weight. Improvement in weight occurred earlier than improvement in height. Among subjects followed up for at least 18 months after gastrostomy, median weight percentile for age increased from 2% for the year before gastrostomy to 12% for the period 6 to 18 months after gastrostomy (P < .001) and 19% for the period 30 to 48 months after gastrostomy (P = .002 compared with before gastrostomy). Other nutritional parameters followed similar, although less dramatic patterns. Gastrostomy feedings were well tolerated and associated with only minor complications. CONCLUSIONS: Long-term gastrostomy feedings appear to be a safe and effective means of improving nutrition in malnourished patients with cystic fibrosis. Clinical dietitians should function as care managers for patients with cystic fibrosis who are receiving supplemental gastrostomy feedings.

The choice of compressor effects the aerosol parameters and the delivery of tobramycin from a single model nebulizer.

Recent U.S. Phase III trials of the aerosolized delivery of tobramycin to cystic fibrosis (CF) patients demonstrated a significant improvement in pulmonary function and in sputum bacterial density. These trials used the Pari LC Plus nebulizer and DeVilbiss Pulmo-Aide compressor. This compressor is not generally available in Europe, and its power requirements do not match the European power supply. Thus alternate compressors were evaluated, using the LC Plus nebulizer, in preparation for European clinical trials. Aerosol particle size distribution, nebulization time (min), and the respirable dose of tobramycin (mg within 1-5 mu) were obtained for seven compressor models. The respirable quantity delivered by each of the European compressors (240 Volts, 50 Hz) was compared to the LC Plus and PulmoAide compressor (120 Volts, at 60 Hz). The U.S. system delivered 71.4 mg of the 300 mg instilled dose within the respirable range; using the European compressors, between 63.0 and 74.8 mg was delivered. With a 97% confidence that the delivered tobramycin was within 20% of the standard, we conclude that the SystAm 23ST, MedicAid CR50 and CR60, Pari Master and the Pari Boy compressors are equivalent to the U.S. standard; the Hercules and the SystAm 26ST compressors were not statistically equivalent to the standard. Using the LC Plus nebulizer, five European compressors delivered doses of TOBI that are similar to the doses delivered by the DeVilbiss PulmoAide compressors, and thus may be expected to produce clinical results similar to those of the U.S. trials.

Bacterial endocarditis due to penicillin-resistant Streptococcus viridans.

Bacterial endocarditis remains a formidable diagnostic and therapeutic problem for clinicians. Streptococcus viridans still accounts for 45 to 50 per cent of all cases and between 5 to 10 per cent of all clinical isolates of Streptococcus viridans from patients with bacterial endocarditis may be relatively resistant to penicillin. The case of a 9-year-old child with Tetralogy of Fallot and a Waterston shunt who subsequently developed bacterial endocarditis due to penicillin-resistant Streptococcus viridans following failure of oral penicillin dental prophylaxis is presented. In the face of penicillin resistance, additional considerations for workup, including microbiological assays for antimicrobial synergism become necessary in the selection of a therapeutic regimen.

Rationale and design of a randomized trial of home electronic symptom and lung function monitoring to detect cystic fibrosis pulmonary exacerbations: the early intervention in cystic fibrosis exacerbation (eICE) trial.

BACKGROUND: Acute pulmonary exacerbations are central events in the lives of individuals with cystic fibrosis (CF). Pulmonary exacerbations lead to impaired lung function, worse quality of life, and shorter survival. We hypothesized that aggressive early treatment of acute pulmonary exacerbation may improve clinical outcomes. PURPOSE: Describe the rationale of an ongoing trial designed to determine the efficacy of home monitoring of both lung function measurements and symptoms for early detection and subsequent early treatment of acute CF pulmonary exacerbations. STUDY DESIGN: A randomized, non-blinded, multi-center trial in 320 individuals with CF aged 14 years and older. The study compares usual care to a twice a week assessment of home spirometry and CF respiratory symptoms using an electronic device with data transmission to the research personnel to identify and trigger early treatment of CF pulmonary exacerbation. Participants will be enrolled in the study for 12 months. The primary endpoint is change in FEV1 (L) from baseline to 12 months determined by a linear mixed effects model incorporating all quarterly FEV1 measurements. Secondary endpoints include time to first acute protocol-defined pulmonary exacerbation, number of acute pulmonary exacerbations, number of hospitalization days for acute pulmonary exacerbation, time from the end of acute pulmonary exacerbation to onset of subsequent pulmonary exacerbation, change in health related quality of life, change in treatment burden, change in CF respiratory symptoms, and adherence to the study protocol. CONCLUSIONS: This study is a first step in establishing alternative approaches to the care of CF pulmonary exacerbations. We hypothesize that early treatment of pulmonary exacerbations has the potential to slow lung function decline, reduce respiratory symptoms and improve the quality of life for individuals with CF.

Patient-reported respiratory symptoms in cystic fibrosis.

BACKGROUND: Cystic fibrosis (CF) specific patient-derived and reported symptom tools are critical steps toward evaluating the outcomes of new therapies for CF. METHODS: We conducted 25 in-depth qualitative interviews using the Day Reconstruction Method and 9 cognitive interviews at two CF programs, the University of Washington and Seattle Children's Hospital and Regional Medical Center. The interviews were audio-recorded and transcribed, and then coded and analyzed for themes relating to pulmonary symptoms and related psychosocial impacts. RESULTS: Six pulmonary symptoms were identified as central to CF: cough, sputum production, wheeze, chest tightness, difficulty breathing/shortness of breath, and fever. Emotional impacts included frustration, sadness/depression, irritability, worry, difficulty sleeping; while activity impacts included time spent sitting or lying down, reduction of usual activities, and missing school or work. In all, 8 symptom items, 4 emotional impacts items, and 4 activity impacts were selected for inclusion on a new daily diary. We also assessed triggers for seeking care. CONCLUSIONS: Using a qualitative inductive methodology, we have obtained patient centered data regarding pulmonary symptoms and burdens and have created a novel patient reported outcome measure for CF. Future studies will assess the validity of the instruments.

Outcome measures for clinical trials in cystic fibrosis. Summary of a Cystic Fibrosis Foundation consensus conference.

The CFF Consensus Conference concluded with a summary of those outcome measures that would be most useful in studies of patients 6 years of age and older and those measures that would be most useful in studies of the younger population (< 6 years of age) (Table). These measures were further divided into biologic markers most appropriate for initial (phase I and phase II) clinical trials and those especially useful in large, multicenter (phase III) pivotal trials. There is an ongoing need to improve the accuracy and validity of currently available measures of biologic activity and clinical efficacy in CF, especially in the younger population. The conference participants recommended that the following eight issues be addressed as soon as possible: (1) definition of pulmonary exacerbation, (2) broadly applicable methods of testing pulmonary function in small children (ideally a single test for all ages), (3) a comprehensive severity-of-disease score for young children, (4) reliable methods of quantifying chest x-ray and CT scan changes in young patients, (5) simple, inexpensive measures of lung inflammation, (6) a centralized, uniform approach to the establishment of data monitoring committees, (7) a quality of well-being scale for small children, and (8) reliable, reproducible aerosol delivery systems with defined characteristics. In addition, participants recommended that better methods be developed for assessing patients' adherence to research protocols.

Comparative monovalent cation transport in neonatal and adult red blood cells.

Active transport of Na and K under physiologic and maximally stressed conditions was identical in normal adult red blood cells (RBC) and term neonatal erythrocytes. These results are consistent with the previous observation that Na-K ATPase is the same in normal adult RBC and term neonatal erythrocytes. These data, however, are at variance with a previous observation that active K transport is impaired in neonatal erythrocytes. The most reasonable explanation for this difference relates to inherent problems with the use of radioisotopes which were used in previous in vitro studies of cation transport.

Association between Stenotrophomonas maltophilia and lung function in cystic fibrosis.

BACKGROUND: Stenotrophomonas maltophilia (SM) is a Gram-negative non-fermenting bacteria cultured from the sputum of patients with cystic fibrosis (CF). To date, no information is available regarding the effect of this organism on lung function in CF. METHODS: A cohort study was conducted to assess the effect of SM on lung function among CF patients aged > or =6 years in the CF Foundation National Patient Registry from 1994 to 1999. Repeated measures regression was used to assess the association between SM and lung function. RESULTS: The cohort consisted of 20 755 patients with median age at entry of 13.8 years and median follow up time of 3.8 years; 2739 patients (13%) were positive at least once for SM and 18 016 (87%) were never positive. After adjusting for sex, height and age, patients with SM had a mean forced expiratory volume in 1 second which was 0.09 l less (95% CI 0.05 to 0.14) than those without SM. The mean rate of decline associated with SM positivity was 0.025 l/year (95% CI 0.012 to 0.037) but, after adjusting for confounders (sex, height, weight, intravenous antibiotic courses, hospital admissions, pancreatic insufficiency, and Pseudomonas aeruginosa and Burkholderia cepacia status), the mean rate of decline decreased to 0.008 l/year (-0.008, 95% CI -0.019 to 0.003). CONCLUSIONS: Although CF patients with SM have worse lung function at the time of positivity, no association was found between SM and increased rate of decline after controlling for confounders.