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Background: Gastrointestinal (GI) complications are a significant source of morbidity for people with cystic fibrosis (PwCF). Historically, dietary recommendations in CF have focused on calories, typically emphasizing a high fat diet. The changing landscape of CF highlights the need to update this nutritional strategy. There is little research into how the quality of calories consumed by PwCF influences nutritional outcomes, GI symptoms, or likely contributors: intestinal inflammation and GI microbiology. We assessed the feasibility of a whole foods-based diet (WFD) and avoidance of ultra-processed foods, measuring safety/tolerability, adherence, and GI symptoms, as well as fecal measures of inflammation and microbiota among children with CF (CwCF) with GI symptoms., Methods: Single center, 4-week dietary intervention involving CwCF aged 5-14 years who screened positive on GI symptom questionnaire. Assessments included weight, symptom questionnaires and adverse events (AEs). Stool was analyzed for microbiota (16S rRNA) and calprotectin., Results: 108 children were pre-screened, 9 enrolled and 8 initiated and completed the study. There were no significant changes in weight and no AEs. PEDS-QL GI identified overall improvement in symptoms. Certain symptom domains (constipation, diarrhea, gas/bloating, stomach pain and hurt) demonstrated significant improvement on the WFD. Of two participants with abnormal fecal calprotectin at enrollment, both exhibited decreased values on WFD. There was no significant change in microbiota diversity., Conclusion: A WFD diet was feasible and safe in CwCF. There was improvement in GI symptom scores based on both parent and child assessments. Larger studies are needed to further investigate effects on intestinal inflammation and microbiota., Competing Interests: Conflict of interest The authors of this manuscript have no conflicts of interest to disclose., (Copyright © 2024 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.)

This study uses CFD methods to investigate the effects of the impeller's geometry on the hemodynamic characteristics, pump performance, and blood damage parameters, in a percutaneous microaxial Mechanical Circulatory Support (MCS) device. The numerical simulations employ the steady state Reynolds-Averaged Navier-Stokes approximation using the SST k-ω turbulent model. Three different impeller models are examined with different hub conversion angles (α = 0 ○ , 3 ○ and 5 ○ ). The analysis includes 23 cases for different pressure heads (Δp = 60-80 mmHg) and angular velocities (ω = 30-52 kRPM). The obtained flow rate is compared between the cases to assess the effect of the impeller's design and working conditions on the pump performance. The comparative risk of shear-induced platelet activation is estimated using the statistical median of the stress-accumulation values calculated along streamlines. The risk of hemolysis is estimated using the average exposure time to shear stress above a threshold (τ > 425 Pa). The results reveal that the shape of the impeller's hub has a great impact on the flow patterns, performance, and risk of blood damage, as well as the angular velocity. The highest flow rate (Q = 3.7 L/min) and efficiency (η = 11.3 %) were achieved using a straight hub (α = 0 ○ ). Similarly, for the same condition of flow and pressure, the straight hub impeller has the lowest blood damage risk parameters. This study shed light on the effect of pump design on the performance and risk of blood damage, indicating the roles of the hub shape and angular velocity as dominant parameters., Competing Interests: Declaration of competing interest We wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Clinical trials often demonstrate treatment efficacy through change in forced expiratory volume in one second (FEV 1 ), comparing single FEV 1 measurements from post- versus pre-treatment timepoints. Day-to-day variation in measured FEV 1 is common for reasons such as diurnal variation and intermittent health changes, relative to a stable, monthly average. This variation can alter estimation of associations between change in FEV 1 and baseline in predictable ways, through a phenomenon called regression to the mean. We quantify and explain day-to-day variation in percent-predicted FEV 1 (ppFEV 1 ) from 4 previous trials, and we present a statistical, data-driven explanation for potential bias in ceiling and floor effects due to commonly observed amounts of variation. We recommend accounting for variation when assessing associations between baseline value and change in CF outcomes in single-arm trials, and we consider possible impact of variation on conventional standards for study eligibility., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Related to other projects, CHG has received consultancy, honoraria and/or travel fees from Enterprise Therapeutics, Gilead Sciences, and Vertex Pharmaceuticals. LJC, EAC, EG, ASM, AP, MR, CST report only CFF and/or NIH grants related to the work., (Copyright © 2024. Published by Elsevier B.V.)

Background: We characterized people with cystic fibrosis (CF) ineligible by genotype (not age) for currently approved CFTR modulator therapy using data from the US CF Foundation Patient Registry (CFFPR)., Methods: We summarized clinical characteristics using CFFPR data from 2017 to 2022. Annual rate of change in percent predicted of forced expiratory volume in one second (ppFEV 1 ) was estimated using generalized estimating equations., Results: A total of 2,790 individuals with CF met inclusion criteria. In 2022, 12 % were less than 6 years old, 16 % were age 6-12 years, 18 % age 12-18 years and 54 % were ≥18 years. The proportion identified as White was 74 %, 17 % Black, and 26 % as Hispanic. The median (IQR) age at diagnosis was 1.2 (0.5, 9.1) months for children and 3.1 (0.3, 17.4) years for adults. Median (IQR) ppFEV 1 among children was 91.9 (80.3; 102.4) and among adults, 74.3 (52.4; 90.4). Pancreatic enzymes were prescribed for 77.8 %. Population-level average (95 % CI) rates of decline in ppFEV 1 among the pancreatic insufficient population was -1.5 per year (-1.8; -1.2) for ages 6 to <11 years, -2.2 per year (-2.6; -1.8) for ages 12 to <18 years, and -1.5 per year (-1.7; -1.3) for adults., Conclusions: We describe the CFTR modulator ineligible population in the US in 2017-2022. With a growing pipeline of therapies aimed at improving CFTR function for those who cannot benefit from modulators due to ineligibility, characterization of both the size and outcomes of these populations are critical to inform optimal clinical development plans and future clinical trials., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Elizabeth Cromwell reports financial support was provided by Cystic Fibrosis Foundation. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

The COVID-19 pandemic necessitated a rapid shift in clinical research to perform virtual visits and remote endpoint assessments, providing a key opportunity to optimize the use of remote endpoints for clinical trials in cystic fibrosis. The use of remote endpoints could allow more diverse participation in clinical trials while minimizing participant burden but must be robustly evaluated to ensure adequate performance and feasibility. In response, the Cystic Fibrosis Foundation convened the Remote Endpoint Task Force (Supplemental Table 1), a multidisciplinary group of CF researchers with remote endpoint expertise and community members tasked to better understand the current and future use of remote endpoints for clinical research. Here, we describe the current use of remote endpoints in CF clinical research, address key unanswered questions regarding their use and feasibility, and discuss the next steps to determine clinical trial readiness., Competing Interests: Declaration of competing interest Related to this work, MEJ reports employment by the Cystic Fibrosis Foundation (CFF). Unrelated to this work the authors report the following: DB reports consulting fees and stocks from Anagram Therapeutics Scientific Advisory Group and is a member of the Board of Directors for Anagram Therapeutics Scientific Advisory Group. CE reports honoraria for teaching presentations from Vertex and Chiesi. CHG reports grant funding from NIH NIDDK and NCRR, CFF, FDA Orphan Prod. Div. He received consulting fees from Enterprise Therapeutics and honoraria from Gilead and Vertex. He has received travel support from Vertex Pharmaceuticals and Enterprise Therapeutics. He participates on the DSMB for Novartis. He is a deputy editor for Annals of the ATS. He has stock in Air Therapeutics. GH reports grant funding from NIH NHLBI and CFF and support from CFCanada for travel. JEH reports grant funding from CFF and NIH, travel support from CF Canada, consulting fees from Vertex Pharmaceuticals and participation on an advisory board for Vertex Pharmaceuticals. DP reports grant funding from the CFF and consulting fees from Renexion Pharma. MSP reports grant funding from Dexcom Inc, CFF and Vertex Pharmaceuticals. She also reports consulting fees from Anagram Therapeutics and honoraria from Vertex Pharmaceuticals and TD Cowan. She is a member of the CFF DSMB and an associate editor for Endocrine Practice: Journal of the American Association of Clinical Endocrinologists. KAR reports grant funding from the CFF. MS reports grant funding from the CFF and Anagram Therapeutics. She has received consulting fees from Nestle International and Alcresta Therapeutics. She has received travel support from the CFF and serves on the CFF DSMB and reports a leadership role in the CFF. JS reports being a member of the CFF DSMB and advisory boards. ST reports honoraria from Vertex Pharmaceuticals. ETZ reports grant funding from CFF, NIH NHLBI, Vertex Pharmaceuticals. She has received consulting fees from CFF and Vertex Phamaceuticals and honoraria from the CFF and Asosciation for Diagnostic and Laboratory Medicine. She has received travel support from Vertex Pharmaceuticals, CFF and European Cystic Fibrosis Society. She has participated on advisory boards for CFF, CFF Therapeutics Development Network and Vertex Pharmaceuticals. MB, NL, KP and MR have no conflicts to report., (Copyright © 2024. Published by Elsevier B.V.)

Background: Relieving gastrointestinal symptoms is a research priority in cystic fibrosis. Emerging evidence highlights effects of cystic fibrosis transmembrane conductance regulator (CFTR) modulators on gastrointestinal function, including pancreatic sufficiency. This study explores ivacaftor licensing and treatment on recorded pancreatic enzyme replacement therapy (PERT) prescription in the US and UK CF registries., Methods: Retrospective longitudinal registry study of recorded pancreatic PERT use between 2008 and 2017. Interrupted time series analysis in propensity-matched cohorts estimated annual change and step change according to ivacaftor eligibility before and after licensing year, 2012. Generalised estimating equations assessed adjusted risk of PERT use in individuals treated with ivacaftor after 2012 compared to untreated individuals., Results: In the US CF registry, the difference in annual change in prevalence of PERT use post-2012 between eligible cases and ineligible controls was -5.0 per 1000 people/year (95 %CI -7.6; -2.3, p = 0.001). The step change and annual change in prevalence of PERT use in eligible cases was not significantly different to controls in the UK CF registry. Relative to the relationship in 2013, ivacaftor treatment in the US CF registry was associated with a lower adjusted risk ratio of PERT use compared to untreated individuals by 2016 (0.97, 95 %CI 0.96; 0.99), which was not observed in the UK CF registry., Conclusions: Licensing of ivacaftor was followed by a lower prevalence of PERT use in the eligible US population compared to pre-licensing period, as well as lower risk of PERT use in those who received treatment. Inconsistencies in US and UK CF registries were observed., Competing Interests: Declaration of competing interest A.R. Smyth has research grants (paid to the University of Nottingham) from Vertex Pharmaceuticals and payment for an advisory board (paid to the University of Nottingham) from Viatris Pharmaceuticals, all outside the current work. A.R. Smyth has patents issued (Camara M, Williams P, Barrett D, Halliday N, Knox A, Smyth A, Fogarty A, Barr H, Forrester D. Alkyl quinolones as biomarkers of Pseudomonas aeruginosa infection and uses thereof. US2016131648-A1; https://pubchem.ncbi.nlm.nih.gov/patent/US-2016131648-A1 Outside the current work, A.R. Smyth reports participation on a Data Safety Monitoring Board for the North American Cystic Fibrosis Foundation Therapeutic Development Network., (Copyright © 2024. Published by Elsevier B.V.)

Posttranslational modifications in fibrinogen resulting from induced oxidation or oxidative stress in the organism can have deleterious influence on optimal functioning of fibrinogen, causing a disturbance in assembly and properties of fibrin. The protective mechanism supporting the ability of fibrinogen to function in ROS-generating environment remains completely unexplored. The effects of very low and moderately low HOCl/ - OCl concentrations on fibrinogen oxidative modifications, the fibrin network structure as well as the kinetics of both fibrinogen-to-fibrin conversion and fibrin hydrolysis have been explored in the current study. As opposed to 25 Μm, HOCl/ - OCl, 10 μM HOCl/ - OCl did not affect the functional activity of fibrinogen. It is shown for the first time that a number of Met residues, AαMet476, AαMet517, AαMet584, BβMet367, γMet264, and γMet94, identified in 10 μM HOCl/-OCl fibrinogen by the HPLC-MS/MS method, operate as ROS scavengers, performing an important antioxidant function. In turn, this indicates that the fibrinogen structure is adapted to the detrimental action of ROS. The results obtained in our study provide evidence for a protective mechanism responsible for maintaining the structure and functioning of fibrinogen molecules in the bloodstream under conditions of mild and moderate oxidative stress., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Ivacaftor (IVA) has been shown to be safe and efficacious in children aged ≥4 months with cystic fibrosis (CF) and CFTR gating variants. We evaluated safety, pharmacokinetics (PK), and efficacy of IVA in a small cohort of infants aged 1 to <4 months with CF., Methods: In this phase 3, open-label study, infants 1 to <4 months with CF and an IVA-responsive CFTR variant received an initial low dose of IVA based on age and weight. Because IVA is a sensitive CYP3A substrate and CYP3A maturation is uncertain in infants, doses were adjusted at day 15 to better match median adult exposures based on individual PK measurements taken on day 4. Primary endpoints were safety and PK measurements., Results: Seven infants (residual function CFTR variants [n=5]; minimal function CFTR variants [n=2]) received ≥1 dose of IVA. Six infants had doses adjusted at day 15 and one infant did not require dose adjustment; subsequent PK analyses showed mean trough concentrations for IVA and metabolites were within range of prior clinical experience. Four infants (57.1%) had adverse events (AEs); no serious AEs were noted. One infant discontinued study drug due to a non-serious AE of elevated alanine aminotransferase >8x the upper limit of normal. Mean sweat chloride concentration decreased (-40.3 mmol/L [SD: 29.2]) through week 24. Improvements in biomarkers of pancreatic function and intestinal inflammation, as well as growth parameters, were observed., Conclusions: In this small, open-label study, IVA dosing in infants achieved exposures previously shown to be safe and efficacious. Because PK was predictable, a dosing regimen based on age and weight is proposed. IVA was generally safe and well tolerated, and led to improvements in CFTR function, markers of pancreatic function and intestinal inflammation, and growth parameters, supporting use in infants as young as 1 month of age., Competing Interests: Declaration of competing interest MR has received research grant funding and an advisory board role for Vertex Pharmaceuticals Incorporated for which her institution received payment. AS has received grants/contracts as a principal investigator from Vertex Pharmaceuticals Incorporated. SAM has received compensation to institution as principal investigator and advisory board consulting fees from Vertex Pharmaceuticals Incorporated. PM has received compensation to his institution as co-investigator, advisory board participation, and honoraria for speaker events from Vertex Pharmaceuticals Incorporated. JD has received payment for clinical trial leadership, advisory board participation, and speaker events from Vertex Pharmaceuticals Incorporated. MH, ML, JL, and VR-R are employees of Vertex Pharmaceuticals Incorporated and may own stock or stock options., (Copyright © 2024. Published by Elsevier B.V.)

Rationale: The American Thoracic Society recommended switching to race-neutral spirometry reference equations, as race is a social construct and to avoid normalizing disparities in lung function due to structural racism. Understanding the impact of the race-neutral equations on percent predicted forced expiratory volume in one second (ppFEV 1 ) in people with cystic fibrosis (PwCF) will help prepare patients and providers to interpret pulmonary function test results., Objective(s): To quantify the impact of switching from Global Lung Initiative (GLI) 2012 race-specific to GLI 2022 Global race-neutral reference equations on the distribution of ppFEV 1 among PwCF of different races., Methods: Cross-sectional analysis of FEV 1 among PwCF ages ≥6 years in the 2021 U.S. Cystic Fibrosis Foundation Patient Registry. We describe the absolute difference in ppFEV 1 between the two reference equations by reported race and the effect of age and height on this difference., Results: With the switch to GLI Global, ppFEV 1 will increase for White (median increase 4.7, (IQR: 3.1; 6.4)) and Asian (2.6 (IQR: 1.6; 3.7)) individuals and decrease for Black individuals (-7.7, (IQR: -10.9; -5.2)). Other race categories will see minimal changes in median ppFEV 1 . Individuals with higher baseline ppFEV 1 and younger age will see a greater change in ppFEV 1 (i.e., a greater improvement among White and Asian individuals and a greater decline among Black individuals)., Conclusions: Switching from GLI 2012 race-specific reference equations to GLI 2022 Global race-neutral equations will result in larger reductions in ppFEV 1 among Black individuals with CF than increases among White and Asian people with CF., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Elizabeth Cromwell reports financial support was provided by Cystic Fibrosis Foundation. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Background: Primary ciliary dyskinesia (PCD) is a rare disorder of motile cilia associated with situs abnormalities. At least 12% of patients with PCD have situs ambiguus (SA), including organ laterality defects falling outside normal arrangement (situs solitus [SS]) or mirror image inversion (situs inversus totalis [SIT])., Research Question: Do patients with PCD and SA achieve worse clinical outcomes compared with those with SS or SIT?, Study Design and Methods: This cross-sectional, multicenter study evaluated participants aged 21 years or younger with PCD. Participants were classified as having SA, including heterotaxy, or not having SA (SS or SIT). Markers of disease severity were compared between situs groups, adjusting for age at enrollment and severe CCDC39 or CCDC40 genotype, using generalized linear models and logistic and Poisson regression., Results: In 397 participants with PCD (mean age, 8.4 years; range, 0.1-21), 42 patients were classified as having SA, including 16 patients (38%) with complex cardiovascular malformations or atrial isomerism, 13 patients (31%) with simple CVM, and 13 patients (31%) without cardiovascular malformations. Of these, 15 patients (36%) underwent cardiac surgery, 24 patients (57%) showed an anatomic spleen abnormality, and seven patients (17%) showed both. The remaining 355 participants did not have SA, including 152 with SIT and 203 with SS. Overall, 70 participants (17%) harbored the severe CCDC39 or CCDC40 genotype. Compared with participants without SA, those with SA showed lower median BMI z scores (P = .03), lower FVC z scores (P = .01), and more hospitalizations and IV antibiotic courses for acute respiratory infections during the 5 years before enrollment (P < .01). Participants with cardiovascular malformations requiring surgery or with anatomic spleen abnormalities showed lower median BMI z scores and more hospitalizations and IV therapies for respiratory illnesses compared with participants without SA., Interpretation: Children with PCD and SA achieve worse nutritional and pulmonary outcomes with more hospitalizations for acute respiratory illnesses than those with SS or SIT combined. Poor nutrition and increased hospitalizations for respiratory infections in participants with SA and PCD are associated with cardiovascular malformations requiring cardiac surgery, splenic anomalies, or both., Trial Registry: ClinicalTrials.gov; Nos.: NCT02389049 and NCT00323167; URL: www., Clinicaltrials: gov., Competing Interests: Financial/Nonfinancial Disclosures The authors have reported to CHEST the following: S. D. Dell, S. D. Davis, T. W. F., M. R., S. D. S., C. M., K. N. O., M. A. Z., M. R. K., M. W. L., A. J. S. report financial support was provided by National Institutes of Health. S. D. Davis, T. W. F., M. W. L., A. J. S. report a relationship with The PCD Foundation that includes: board membership. A. J. S. reports a relationship with The PCD Foundation that includes: employment. S. D. Davis receives grant support from ReCode Therapeutics. A. J. S. receives grant support from The Chest Foundation. T. W. F. served as a consultant for Translate Bio and Arrowhead Pharmaceuticals. T. W. F. and A. J. S. are advisory board members for Parion Sciences and ReCode Therapeutics. None declared (K. R. K., A. T. B., W. W., F.-C. L., L. L., E. R.)., (Copyright © 2023 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

This is the third in a series of four papers updating the European Cystic Fibrosis Society (ECFS) standards for the care of people with CF. This paper focuses on recognising and addressing CF health issues. The guidance was produced with wide stakeholder engagement, including people from the CF community, using an evidence-based framework. Authors contributed sections, and summary statements which were reviewed by a Delphi consultation. Monitoring and treating airway infection, inflammation and pulmonary exacerbations remains important, despite the widespread availability of CFTR modulators and their accompanying health improvements. Extrapulmonary CF-specific health issues persist, such as diabetes, liver disease, bone disease, stones and other renal issues, and intestinal obstruction. These health issues require multidisciplinary care with input from the relevant specialists. Cancer is more common in people with CF compared to the general population, and requires regular screening. The CF life journey requires mental and emotional adaptation to psychosocial and physical challenges, with support from the CF team and the CF psychologist. This is particularly important when life gets challenging, with disease progression requiring increased treatments, breathing support and potentially transplantation. Planning for end of life remains a necessary aspect of care and should be discussed openly, honestly, with sensitivity and compassion for the person with CF and their family. CF teams should proactively recognise and address CF-specific health issues, and support mental and emotional wellbeing while accompanying people with CF and their families on their life journey., Competing Interests: Declaration of competing interest The authors had no declarations of interest in relation to the current work. Declarations of interest for each author outside the current work are summarised in Supplementary Table 4., (Copyright © 2024. Published by Elsevier B.V.)

Background: Hyperglycemia could affect treatment response during cystic fibrosis (CF) exacerbations. We aimed to evaluate the prevalence and associations of hyperglycemia with exacerbation outcomes. We also evaluated feasibility of continuous glucose monitoring (CGM) during exacerbations., Methods: The STOP2 study assessed efficacy and safety of different durations of intravenous antibiotics for CF exacerbations. We conducted a secondary data analysis of random glucose levels measured as part of clinical care during exacerbations. A small subset of participants also underwent CGM per research protocol. The associations between hyperglycemia, defined as random glucose ≥140 mg/dL, and changes in weight and lung function with exacerbation treatment were evaluated with linear regression after adjustment for confounding variables., Results: Glucose levels were available for 182 STOP2 participants of mean (SD) age 31.6 (10.8) years, baseline percent predicted (pp) FEV1 53.6 (22.5); 37% had CF related diabetes and 27% were on insulin. Hyperglycemia was detected in 44% of participants. Adjusted mean difference (95% CI) was 1.34% (-1.39, 4.08) (p = 0.336) for change in ppFEV1 and 0.33 kg (-0.11, 0.78) (p = 0.145) for change in weight between hyperglycemic and non-hyperglycemic groups. Ten participants not on antidiabetic agents in the 4 weeks prior to enrollment underwent CGM; mean (SD) time spent >140 mg/dL was 24.6% (12.5) with 9/10 participants spending >4.5% time >140 mg/dL., Conclusions: Hyperglycemia identified with random glucose is prevalent during CF exacerbations but not associated with changes in lung function or weight with exacerbation treatment. CGM is feasible and may provide a useful tool for hyperglycemia monitoring during exacerbations., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Background: Pseudomonas aeruginosa (Pa) infection in cystic fibrosis (CF) is characterized in stages: never (prior to first positive culture) to incident (first positive culture) to chronic. The association of Pa infection stage with lung function trajectory is poorly understood and the impact of age on this association has not been examined. We hypothesized that FEV 1 decline would be slowest prior to Pa infection, intermediate after incident infection and greatest after chronic Pa infection., Methods: Participants in a large US prospective cohort study diagnosed with CF prior to age 3 contributed data through the U.S. CF Patient Registry. Cubic spline linear mixed effects models were used to evaluate the longitudinal association of Pa stage (never, incident, chronic using 4 different definitions) with FEV 1 adjusted for relevant covariates . Models contained interaction terms between age and Pa stage., Results: 1,264 subjects born 1992-2006 provided a median 9.5 (IQR 0.25 to 15.75) years of follow up through 2017. 89% developed incident Pa; 39-58% developed chronic Pa depending on the definition. Compared to never Pa, incident Pa infection was associated with greater annual FEV 1 decline and chronic Pa infection with the greatest FEV 1 decline. The most rapid FEV 1 decline and strongest association with Pa infection stage was seen in early adolescence (ages 12-15)., Conclusions: Annual FEV 1 decline worsens significantly with each Pa infection stage in children with CF. Our findings suggest that measures to prevent chronic infection, particularly during the high-risk period of early adolescence, could mitigate FEV 1 decline and improve survival., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest to declare, (Copyright © 2023. Published by Elsevier B.V.)

Background: SHIP-CT showed that 48-week treatment with inhaled 7% hypertonic saline (HS) reduced airway abnormalities on chest CT using the manual PRAGMA-CF method relative to isotonic saline (IS) in children aged 3-6 years with cystic fibrosis (CF). An algorithm was developed and validated to automatically measure bronchus and artery (BA) dimensions of BA-pairs on chest CT. Aim of the study was to assess the effect of HS on bronchial wall thickening and bronchial widening using the BA-analysis., Methods: The BA-analysis (LungQ, version 2.1.0.1, Thirona, Netherlands) automatically segments the bronchial tree and identifies the segmental bronchi (G 0 ) and distal generations (G 1 -G 10 ). Dimensions of each BA-pair are measured: diameters of bronchial outer wall (B out ), bronchial inner wall (B in ), bronchial wall thickness (B wt ), and artery (A). BA-ratios are computed: B out /A and B in /A to detect bronchial widening and B wt /A and B wa /B oa (=bronchial wall area/bronchial outer area) to detect bronchial wall thickening., Results: 113 baseline and 102 48-week scans of 115 SHIP-CT participants were analysed. LungQ measured at baseline and 48-weeks respectively 6,073 and 7,407 BA-pairs in the IS-group and 6,363 and 6,840 BA-pairs in the HS-group. At 48 weeks, B wt /A (mean difference 0.011; 95%CI, 0.0017 to 0.020) and B wa /B oa (mean difference 0.030; 95% 0.009 to 0.052) was significantly higher (worse) in the IS-group compared to the HS-group representing more severe bronchial wall thickening in the IS-group (p=0.025 and p=0.019 respectively). B wt /A and B wa /B oa decreased and B in /A remained stable from baseline to 48 weeks in the HS while it declined in the IS-group (all p<0.001). There was no difference in progression of B out /A between two treatment groups., Conclusion: The automatic BA-analysis showed a positive impact of inhaled HS on bronchial lumen and wall thickness, but no treatment effect on progression of bronchial widening over 48 weeks., Competing Interests: Declaration of Competing Interest HAWMT reports grants from the Cystic Fibrosis Foundation and Health Holland, has received in the last 5 years multiple grants from the following public and institutional grant institutions for lung structure and function research: NHMRC, NIH, CFF, ECFS, IMI, Sophia Foundation and unconditional grants for investigator-initiated research from Chiesi, Vectura, Novartis, and Insmed, has acted as consultant for Insmed, TBIO, Thirona, Neupharma and Boehringer, has a part time position as chief medical officer for Thirona, functions as vice chair and faculty for the Advance course sponsored by Vertex, and owns no shares. Erasmus MC and Telethon Kids Institute have licensed the use of PRAGMA-CF to Thirona and Resonance Health. LGE is a scientist working at Thirona. JPC is Co-founder and shareholder at Thirona. DC is director of the Erasmus MC- LungAnalysis laboratory. SDD reports grants from Cystic Fibrosis Foundation. MR reports grants from Cystic Fibrosis Foundation. FR serves as consultant for Vertex, Bayer, Roche, Genentech, and Proteostasis. RAK reports grants from Cystic Fibrosis Foundation. KDHS reports grants from Cystic Fibrosis Foundation. SMS reports grants from the Cystic Fibrosis Foundation and National Health and Medical Research Foundation and Erasmus MC and Telethon Kids Institute have licensed the use of PRAGMA-CF to Thirona and Resonance Health. All other authors declare no competing interests., (Copyright © 2023. Published by Elsevier B.V.)

Background: No data exist to guide antibiotic selection among people with CF (PwCF) with respiratory cultures positive for multiple CF-related bacteria (polymicrobial infections). This study aimed to describe the number of polymicrobial in-hospital treated pulmonary exacerbations (PEx), to determine the proportion of polymicrobial PEx where antibiotics were prescribed with activity against all bacteria detected (termed complete antibiotic coverage), and to determine clinical and demographic factors associated with complete antibiotic coverage., Methods: Retrospective cohort study using the CF Foundation Patient Registry-Pediatric Health Information System dataset. Children aged 1-21 years with an in-hospital treated PEx from 2006 to 2019 were eligible for inclusion. Bacterial culture positivity was based on any positive respiratory culture in the 12 months prior to a study PEx., Results: A total of 4,923 children contributed 27,669 total PEx of which 20,214 were polymicrobial; of these, 68% of PEx had complete antibiotic coverage. In regression modeling, a prior PEx with complete antibiotic coverage for MRSA was associated with a higher likelihood of having complete antibiotic coverage at a subsequent study PEx (OR (95% CI) 3.48 (2.50, 4.83))., Conclusions: The majority of children with CF hospitalized for polymicrobial PEx were prescribed complete antibiotic coverage. Prior PEx treatment with complete antibiotic coverage predicted complete antibiotic coverage at a future PEx for all bacteria studied. Studies are needed comparing outcomes of polymicrobial PEx treated with different antibiotic coverages to optimize PEx antibiotic selection., (Copyright © 2023 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Background: Elexacaftor/tezacaftor/ivacaftor (ETI) improves pulmonary disease in people with cystic fibrosis (PwCF), but its effect on gastrointestinal symptoms, which also affect quality of life, is not clear., Methods: PROMISE is a 56-center prospective, observational study of ETI in PwCF >12 years and at least one F508del allele. Gastrointestinal symptoms, evaluated by validated questionnaires: Patient Assessment of Upper Gastrointestinal Disorders-Symptom (PAGI-SYM), Patient Assessment of Constipation-Symptom (PAC-SYM), Patient Assessment of Constipation-Quality of Life (PAC-QOL)), fecal calprotectin, steatocrit and elastase-1 were measured before and 6 months after ETI initiation. Mean difference and 95% confidence intervals were obtained from linear regression with adjustment for age and sex., Results: 438 participants fully completed at least 1 questionnaire. Mean (SD) for baseline PAGI-SYM, PAC-SYM, and PAC-QOL total scores were 0.56 (0.59), 0.47 (0.45), and 0.69 (0.53) out of maximum 5, 4, and 5, respectively (higher score indicates greater severity). Corresponding age- and sex-adjusted 6 months mean changes (95% CI) in total scores were -0.15 (-0.21, -0.09) for PAGI-SYM, -0.14 (-0.19, -0.09) for PAC-SYM, and -0.15 (-0.21, -0.10) for PAC-QOL. While statistically significant, changes were small and unlikely to be of clinical importance. Fecal calprotectin showed a change (95% CI) from baseline of -66.2 µg/g (-86.1, -46.2) at 6 months, while fecal elastase and steatocrit did not meaningfully change., Conclusions: After 6 months of ETI, fecal markers of inflammation decreased. Gastrointestinal symptoms improved, but the effect size was small. Pancreatic insufficiency did not improve., Competing Interests: Declaration of Competing Interest SJS-Consultant for UpToDate, Abbvie, Mirium, Nestle; Grant funding from Gilead, Cystic Fibrosis Foundation, NIH. SDF – Consultant for UpToDate, Abbvie, Nestle, Synspira; Grant funding from NIH, Cystic Fibrosis Foundation, Amagma Therapeutics. MRN – Consultant for UpToDate, Vertex: Grant funding from Gilead, AbbVie, Cystic Fibrosis Foundation, NIH SMR: Consultant for Vertex; Grant funding from Vertex, Cystic Fibrosis Foundation, NIH DPN: Consultant for Vertex, Genentech; Grant funding from Vertex, Cystic Fibrosis Foundation, NIH GMS: Consultant for Genentech, Electromed; Grant Funding from Vertex, Cystic Fibrosis Foundation, NIH DG: Consultant for Vertex, Abbvie, Chiesi USA, Eli Lilly AK: Grant funding from NIH, Cystic Fibrosis Foundation, SDS – Grant funding from Cystic Fibrosis Foundation and NIH MSS—Grant funding from Cystic Fibrosis Foundation, (Copyright © 2022. Published by Elsevier B.V.)

Background: Club cell secretory protein (CC16) exerts anti-inflammatory functions in lung disease. We sought to determine the relation of serum CC16 deficits and genetic variants that control serum CC16 to lung function among children with cystic fibrosis (CF)., Methods: We used longitudinal data from CF children (EPIC Study) with no positive cultures for Pseudomonas aeruginosa prior to enrollment. Circulating levels of CC16 and an inflammatory score (generated from CRP, SAA, calprotectin, G-CSF) were compared between participants with the lowest and highest FEV 1 levels in adolescence (LLF and HLF groups, respectively; N = 130-per-group). Single nucleotide variants (SNVs) in the SCGB1A1, EHF-APIP loci were tested for association with circulating CC16 and with decline of FEV 1 and FEV 1 /FVC% predicted levels between ages 7-16 using mixed models., Results: Compared with the HLF group, the LLF group had lower levels of CC16 (geometric means: 8.2 vs 6.5 ng/ml, respectively; p = 0.0002) and higher levels of the normalized inflammatory score (-0.21 vs 0.21, p = 0.0007). Participants in the lowest CC16 and highest inflammation tertile had the highest odds for having LLF (p<0.0001 for comparison with participants in the highest CC16 and lowest inflammation tertile). Among seven SNVs associated with circulating CC16, the top SNV rs3741240 was associated with decline of FEV 1 /FVC and, marginally, FEV 1 (p = 0.003 and 0.025, respectively; N = 611 participants, 20,801 lung function observations)., Conclusions: Serum CC16 deficits are strongly associated with severity of CF lung disease and their effects are additive with systemic inflammation. The rs3741240 A allele is associated with low circulating CC16 and, possibly, accelerated lung function decline in CF., Competing Interests: Declaration of Competing Interest MJE, EEB, KJB, MH, RLG, MR, SDS, MJB, WJM, and SG report receiving grant support through their institution for the present work. SDS reports receiving honoraria from DKBMed. WJM reports receiving consulting fees from the Cystic Fibrosis Foundation, receiving speaker honoraria from the American College of Chest Physicians, and participating on the CFF DSMB., (Copyright © 2022. Published by Elsevier B.V.)

Competing Interests: FR declares grants, consulting, or honorarium from Vertex, and has acted as a consultant for Proteostasis, TranslateBio, Boehringer Ingelheim, and Calitheria, for activities related to cystic fibrosis. MR declares no competing interests.

Background: In the Saline Hypertonic in Preschoolers (SHIP) study, inhaled 7% hypertonic saline improved the lung clearance index in children aged 3-6 years with cystic fibrosis, but it remained unclear whether improvement is also seen in structural lung disease. We aimed to assess the effect of inhaled hypertonic saline on chest CT imaging in children aged 3-6 years with cystic fibrosis., Methods: Children with cystic fibrosis were enrolled in this multicentre, randomised, double-blind, controlled study at 23 cystic fibrosis centres in Spain, Denmark, the Netherlands, Italy, France, Belgium, the USA, Canada, and Australia. Eligible participants were children aged 3-6 years who were able to cooperate with chest CT imaging and comply with daily nebuliser treatment. Participants were randomly assigned 1:1 to receive inhaled 2 puffs of 100 μg salbutamol followed by 4mL of either 7% hypertonic saline or 0·9% isotonic saline twice per day for 48 weeks. Randomisation was stratified by age in North America and Australia, and by age and country in Europe. Chest CTs were obtained at baseline and 48 weeks and scored using the Perth-Rotterdam Annotated Grid Morphometric Analysis for Cystic Fibrosis (PRAGMA-CF) method. The primary outcome was the difference between groups in the percentage of total lung volume occupied by abnormal airways (PRAGMA-CF %Disease) measured by chest CT at 48 weeks. Analysis was by intention-to-treat. This study is registered with Clinicaltrials.gov, NCT02950883., Findings: Between May 24, 2016, and Dec 18, 2019, 134 children were assessed for inclusion. 18 patients were excluded (nine had incomplete or unsuccessful chest CT at enrolment visit, two could not comply with CT training, two had acute respiratory infection, two withdrew consent, two for reasons unknown, and one was already on hypertonic saline). 116 participants were enrolled and randomly assigned to hypertonic saline (n=56) or isotonic saline (n=60). 12 patients dropped out of the study (seven in the hypertonic saline group and five in the isotonic saline group). Mean PRAGMA-CF %Disease at 48 weeks was 0·88% (95% CI 0·60-1·16) in the hypertonic saline group and 1·55% (1·25-1·84) in the isotonic saline group (mean difference 0·67%, 95% CI 0·26-1·08; p=0·0092) based on a linear regression model adjusted for baseline %Disease values and baseline age. Most adverse events in both groups were rated as mild, and the most common adverse event in both groups was cough., Interpretation: Inhaled hypertonic saline for 48 weeks had a positive effect on structural lung changes in children aged 3-6 years with cystic fibrosis relative to isotonic saline. This is the first demonstration of an intervention that alters structural lung disease in children aged 3-6 years with cystic fibrosis., Funding: Cystic Fibrosis Foundation., Competing Interests: Declaration of interests HAWMT reports grants from the Cystic Fibrosis Foundation and Health Holland, is director of the Erasmus MC- LungAnalysis laboratory, which also acts as the ECFS-CTN CT expert centre, and serves as consultant for Thirona on image analysis. Erasmus MC is expected to receive future license royalties for PRAGMA-CF. SDD reports grants from Cystic Fibrosis Foundation. MR reports grants from Cystic Fibrosis Foundation. FR served as consultant for Vertex, Bayer, Roche, Genentech, and Proteostasis. RAK reports grants from Cystic Fibrosis Foundation. KDHS reports grants from Cystic Fibrosis Foundation. SMS reports grants from the Cystic Fibrosis Foundation and National Health and Medical Research Foundation, and Telethon Kids Institute is expected to receive future license royalties for PRAGMA-CF. All other authors declare no competing interests., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

In this study, we examined for the first time the effect of the HOCl/OCl - - and H 2 O 2 -induced oxidation of Glu-plasminogen on damage to its primary structure and the biological activity of plasmin. The consolidated results obtained with the aid of MS/MS, electrophoresis, and colourimetry, demonstrated that none of the oxidised amino acid residues found in the proenzyme treated with 25 μM HOCl/OCl - or 100 μM H 2 O 2 were functionally significant for plasminogen. However, the treatment of plasminogen with increasing concentrations of HOCl/OCl - from 25 μM to 100 μM or H 2 O 2 from 100 μM to 300 μM promoted a partial loss in the activity of oxidised plasmin. Several methionine residues (Met57, Met182, Met385, Met404, Met585, and Met788) localized in different protein domains have been shown to serve as ROS traps, thus providing an efficient defense mechanism against oxidative stress. Oxidised Trp235, Trp417, Trp427, Trp761, and Tyr672 are most likely responsible for the reduced biological activity of Glu-plasminogen subjected to strong oxidation. The results of the present study, along with those of previous studies, indicate that the structure of Glu-plasminogen is adapted to oxidation to withstand oxidative stress induced by ROS., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Chronic Pseudomonas aeruginosa (Pa) infection is associated with increased morbidity and mortality in people with cystic fibrosis (CF). There is no gold standard definition of chronic Pa infection in CF. We compared chronic Pa definitions using encounter-based versus annualized data in the Early Pseudomonas Infection Control (EPIC) Observational study cohort, and subsequently compared annualized chronic Pa definitions across a range of U.S. cohorts spanning decades of CF care. We found that an annualized chronic Pa definition requiring at least 1 Pa+ culture in 3 of 4 consecutive years ("Green 3/4") resulted in chronic Pa metrics similar to established encounter-based modified Leeds criteria definitions, including a similar age at and proportion who fulfilled chronic Pa criteria, and a similar proportion with sustained Pa infection after meeting the chronic Pa definition. The Green 3/4 chronic Pa definition will be valuable for longitudinal analyses in cohorts with limited culture frequency., Competing Interests: Conflict of interest statement All authors confirm that they have no conflicts of interest relevant to this work, (Copyright © 2021. Published by Elsevier B.V.)

Studies have demonstrated that people with CF with pancreatic insufficiency (PI) have fecal dysbioses. Evidence suggests the causes of these dysbioses are multifactorial, and that important drivers include antibiotic exposure, dietary intake, and CF gastrointestinal tract dysfunction, including nutrient malabsorption. In this pilot study, we tested whether initiation of the CFTR modulator treatments ivacaftor (in a cohort of pancreatic sufficient (PS) people with CF and an R117H CFTR variant) or lumacaftor/ivacaftor (in a cohort of PI people with CF and an F508del variant) changed fecal measures of malabsorption or fecal microbiomes. While we identified no statistically significant fecal changes with either treatment, we detected trends in the PI cohort when initiating lumacaftor/ivacaftor towards decreased fecal fat content and towards fecal microbiomes that more closely resembled the fecal microbiota of people without PI. While these findings support a model in which nutrient malabsorption resulting from CF-induced PI drives fecal dysbiosis, they must be validated in future, larger studies of fecal microbiome and malabsorption outcomes with highly effective CFTR modulator therapies., Competing Interests: Declaration of Competing Interest The authors declare no relevant conflicts of interest beyond the funding listed in Acknowledgments., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Objectives: We evaluated the value of BioFire® FilmArray® pneumonia panel in establishing a microbiological diagnosis of pneumonia. We evaluated opportunities for antimicrobial optimization from its use., Methods: We included adult patients with pneumonia between May 2019 and January 2020. The pneumonia panel was used on high-quality sputum specimens, and the results were prospectively compared with sputum cultures and other tests performed according to standard of care., Results: Seventy patients were included, sixty-nine of whom completed a 5-day antimicrobial course for pneumonia, and 14.3% died during hospitalization. There was a trend of higher rate of microbiological diagnosis among the patients with culture submitted before antimicrobial administration (9/15 vs. 20/55; p = 0.09). The panel increased the microbiological diagnosis from 29/70 to 59/70 (p < 0.001) patients. The per isolate analysis revealed an increase in the isolation of Haemophilus influenzae (p = 0.002) and Streptococcus pneumoniae (p = 0.05). On review of empiric antimicrobials, there was potential for antimicrobial optimization in 56/70 patients, including 9 bacteria among 9 patients, which were not covered by empiric treatment and another 70 antimicrobials in 49 patients that could have been stopped., Conclusions: Incorporation of the pneumonia panel in the diagnostic work-up of pneumonia substantially increased the rate of microbiological diagnosis and revealed abundant opportunities for antimicrobial optimization., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Highly effective CFTR modulator drug therapy is increasingly available to those with cystic fibrosis. Multiple observational research studies are now being conducted to better understand the impacts of this important therapeutic milestone on long-term outcomes, patient care needs, and future research priorities. PROMISE is a large, multi-disciplinary academic study focused on the broad impacts of starting elexacaftor/tezacaftor/ivacaftor in the US population age 6 years and older. The many areas of investigation and rationale for each are discussed by organ systems, along with recognition of remaining important questions that will not be addressed by this study alone. Knowledge gained through this and multiple complementary studies around the world will help to understand important health outcomes, clinical care priorities, and research needs for a large majority of people treated with these or similarly effective medications targeting the primary cellular impairment in cystic fibrosis., Competing Interests: Declaration of Competing Interest The primary author declares no conflict of interest with the content of this manuscript. Any potential conflicts of interest among all authors related to funding or other financial agreements will be collected and updated during the review process., (Copyright © 2021. Published by Elsevier B.V.)

Background: Most studies of pulmonary exacerbations (PEx) in cystic fibrosis (CF) focus on intravenous (IV)-treated PEx, though most PEx are treated with oral antibiotics. Our objectives were to describe predictors of antibiotic choice and outcomes for PEx initially identified in clinic., Methods: For each patient in the U.S. CF Foundation Patient Registry, we selected the first PEx recorded at a clinic visit in 2013-14 following a clinic visit without a PEx. We used multivariable logistic regression to determine associations between clinical characteristics and antibiotic treatment choice. We determined outcomes in the 90 days after the first PEx., Results: Among 14,265 patients with a PEx initially identified in clinic, 21.4% received no antibiotics, 61.5% received new oral and/or inhaled antibiotics, and 17.0% had IV antibiotics within 14 days. Compared to IV antibiotics, patients more likely to receive new oral and/or inhaled antibiotics: were male, <13 years old, had BMI >10th percentile or 18.5 kg/m 2 , >90 days between clinic visits, FEV 1  > 70% predicted at the PEx, no prior-year IV-treated PEx, FEV 1 decline <10% predicted, and private insurance. Following the PEx, 30.3% of patients had no clinical encounters within 90 days. Treatment with IV antibiotics within 90 days occurred for 23.7% treated without antibiotics, 22.8% of new oral and/or inhaled antibiotics, and 27.1% of IV antibiotics., Conclusion: Most PEx identified in clinic are treated with new oral and/or inhaled antibiotics. Markers of disease severity are associated with antibiotic treatment choice. Many patients had no follow-up evaluation within 90 days of treatment., (Copyright © 2019 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Background: Pulmonary exacerbations (PEx) are important contributors to morbidity and mortality in cystic fibrosis (CF). Understanding risk factors for PEx is critical to improve treatment; pulmonary exacerbations also serve as an important outcome in CF clinical trials. Current risk estimates generally only evaluate time to the first PEx. Methods accounting for multiple exacerbations during the observation period could provide more power to detect significant risk factors., Methods: The Early Pseudomonas Infection Control (EPIC) Observational Study enrolled participants between 2004 and 2006 who were ≤ 12 years of age and negative for Pseudomonas aeruginosa. First and multiple event analyses were used to investigate risk factors for pulmonary exacerbations., Results: We evaluated a total of 5129 PEx from 1734 CF patients in the EPIC study. Multiple event analysis identified 2 more factors associated with occurrence of PEx compared to first event analysis. After adjusting for multiple factors, the following were associated with higher occurrence of PExs: female gender, older age at enrollment, household cigarette smoke exposure, increased cough at the most recent encounter, having used antibiotics since the previous encounter, a positive culture for any CF organism at the most recent encounter, and having had a PEx in the last 30 days., Conclusions: Multiple event analyses use all PEx events and may identify more risk factors for PEx than analysis of time to first PEx. We have provided an example of how to apply this type of analysis and how to interpret estimates in the context of the EPIC study., (Published by Elsevier B.V.)

Background: KIWI (NCT01705145) was a 24-week, single-arm, pharmacokinetics, safety, and efficacy study of ivacaftor in children aged 2 to 5 years with cystic fibrosis (CF) and a CFTR gating mutation. Here, we report the results of KLIMB (NCT01946412), an 84-week, open-label extension of KIWI., Methods: Children received age- and weight-based ivacaftor dosages for 84 weeks. The primary outcome was safety. Other outcomes included sweat chloride, growth parameters, and measures of pancreatic function., Results: All 33 children who completed KIWI enrolled in KLIMB; 28 completed 84 weeks of treatment. Most adverse events were consistent with those reported during KIWI. Ten (30%) children had transaminase elevations >3 × upper limit of normal (ULN), leading to 1 discontinuation in a child with alanine aminotransferase >8 × ULN. Improvements in sweat chloride, weight, and body mass index z scores and fecal elastase-1 observed during KIWI were maintained during KLIMB; there was no further improvement in these parameters., Conclusions: Ivacaftor was generally well tolerated for up to 108 weeks in children aged 2 to 5 years with CF and a gating mutation, with safety consistent with the KIWI study. Improvements in sweat chloride and growth parameters during the initial 24 weeks of treatment were maintained for up to an additional 84 weeks of treatment. Prevalence of raised transaminases remained stable and did not increase with duration of exposure during the open-label extension., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Inhaled hypertonic saline enhances mucociliary clearance, improves lung function, and reduces pulmonary exacerbations in people with cystic fibrosis older than age 6 years. We aimed to assess the effect of inhaled hypertonic saline on the lung clearance index (LCI 2·5 )-a measure of ventilation inhomogeneity-in children aged 3-6 years with cystic fibrosis., Methods: The Saline Hypertonic in Preschoolers (SHIP) Study was a randomised, double-blind, placebo-controlled trial at 25 cystic fibrosis centres in Canada and the USA. Eligible participants were aged 36-72 months; had a confirmed diagnosis of cystic fibrosis; were able to comply with medication use, study visits, and study procedures; and were able to complete at least two technically acceptable trials of multiple breath washout (MBW). Participants were randomly assigned (1:1) via a web-based data entry system that confirmed enrolment eligibility to inhaled 7% hypertonic saline or 0·9% isotonic saline nebulised twice daily (for no more than 15 min per dose) for 48 weeks. Permuted block randomisation was done separately for participants aged 36-54 months and those aged 55-72 months to ensure approximate balance by treatment group in the two age groups. The primary endpoint was the change in the LCI 2·5 measured by nitrogen MBW from baseline to week 48. All study sites were trained and certified in MBW. Analysis was by intention to treat. This study is registered with Clinicaltrials.gov, number NCT02378467., Findings: Between April 21, 2015, and Aug 4, 2017, 150 participants were enrolled and randomly assigned, 76 to the hypertonic saline group and 74 to the isotonic saline group. Overall 89% of the MBW tests produced acceptable data. At 48 weeks, treatment with hypertonic saline was associated with a significant decrease (ie, improvement) in LCI 2·5 compared with isotonic saline (mean treatment effect -0·63 LCI 2·5 units [95% CI -1·10 to -0·15]; p=0·010). Six participants in the hypertonic saline group had ten serious adverse events and eight participants in the isotonic saline group had nine serious adverse events. The serious adverse events reported were cough (two patients [3%] in the hypertonic saline group vs three [4%] in the isotonic saline group), gastrostomy tube placement or rupture (two [3%] vs one [1%]), upper gastrointestinal disorders (one [1%] vs two [3%]), distal intestinal obstruction syndrome (one [1%] vs one [1%]), and decreased pulmonary function (none vs one [1%]). None of these serious adverse events was judged to be treatment related., Interpretation: Inhaled hypertonic saline improved the LCI 2·5 in children aged 3-6 years, and could be a suitable early intervention in cystic fibrosis., Funding: Cystic Fibrosis Foundation., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: American Indian (AI)/Alaska Native children have increased asthma prevalence, morbidity, and mortality compared to non-Hispanic white children. Our study sought to examine environmental and socioeconomic factors of asthma among children in an AI community., Methods: This case-control study included children with physician-diagnosed asthma and age-matched controls, ages 6 through 17 years, in an AI community. Diagnosis and clinical characteristics were obtained from medical record review. Home visits included interviews regarding sociodemographic and household environmental exposures, physical exams, spirometry, and asthma control questionnaires (cases only)., Results: Among the 108 asthma cases and 215 controls, 64% had an annual household income of <$25,000. Children with asthma had significantly higher odds of living in a multi-unit dwelling (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.2-4.4) or in residences with rodent or insect infestation (OR, 2.1; 95% CI, 1.1-3.8) and were less likely to live in homes with more than 8 occupants (OR, 0.5; 95% CI, 0.3-0.9). Also, there was a trend for lower caregiver education level, unmarried caregiver marital status, and annual household income level of <$25,000 in univariate analysis. However, after adjustment for socioeconomic status and household environmental factors, these estimates were not significant. Nearly half of cases had poorly controlled asthma and reported persistent cough, wheeze, and dyspnea, yet only 24% reported using a controller medication., Conclusions: In this low-income AI community, we identified several social and environmental determinants of asthma, which were mediated by socioeconomic status and other household environmental factors, suggesting a complex interplay between socioeconomic status and environmental exposures. Furthermore, many children with asthma reported poor asthma control., (Published by Elsevier Inc.)

Background: The literature conflicts regarding dental caries risk in cystic fibrosis (CF) relative to controls., Methods: Prospective, observational study of age-related heterogeneity in caries rates and potential risk factors in individuals with CF ages 6-20 at a single clinic in Washington state (N=85). Caries rates for enrolled CF participants and historical controls from NHANES were compared using cubic spline regression models. Generalized linear regression models identified correlates of age and caries in CF., Results: Children ages 6-9 with CF had significantly lower caries than controls (Holm's P<0.05). There was no difference for ages 10-20 by CF status (Holm's P>0.05). Various biological/intraoral, medical, and behavioral factors were associated with caries and age in CF., Conclusions: Younger children with CF may be protected from caries, but there is apparent loss of protection in early adolescence associated with multiple risk factors. Additional studies are needed to confirm these findings., (Copyright © 2018 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Purpose: Patient-reported outcomes are important clinical trial endpoints. Young children may not be able to reliably report on how they feel or function, so observer-reported outcomes (ObsROs) may be more appropriate for them. The purpose of this study was to develop and pilot field test electronic parent-reported observational instruments for children with cystic fibrosis (CF) 0-6 and 7-11years of age., Methods: We performed concept elicitation interviews with parents of children with CF ≤11years of age to elicit the respiratory signs they could observe at baseline and during an acute respiratory illness. The resulting instruments were refined based on interviews with parents and clinicians. We conducted a pilot field test to evaluate test-retest reliability and the ability of items to distinguish well and sick periods., Results: The instruments consist of 17 items assessing respiratory signs and observable CF-related impacts. Test-retest reliability was acceptable for both age groups but discrimination was low for ages 7-11, likely reflecting less direct observation of older children by their parents., Conclusions: An ObsRO for children with CF ages 0-6 appears promising, while self-report may be more appropriate for children >6years of age. Next steps for the 0-6year old instrument will be utilizing it as an exploratory endpoint in clinical trials to enable item reduction, scale development, and further reliability and validity testing. Ultimately, this ObsRO could be a promising endpoint for early intervention trials in young children with CF., (Copyright © 2018 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Plasma fibrin-stabilizing factor (pFXIII) is a heterotetrameric proenzyme composed of two catalytic A subunits (FXIII-A 2 ) and two inhibitory/carrier B subunits (FXIII-B 2 ). The main function of the protein is the formation of cross-links between the polypeptide chains of the fibrin clot. The conversion of pFXIII into the enzymatic form FXIII-A 2 * is a multistage process. Like many other blood plasma proteins, pFXIII is an oxidant-susceptible target. The influence of distinct sites susceptible to oxidation-mediated modifications on the changes in the structural-functional characteristics of the protein remains fully unexplored. For the first time, a set of the oxidation sites within FXIII-A 2 under ozone-induced oxidation of pFXIII at different stages of its activation have been identified by mass spectrometry, and the extent as well as the chemical nature of these modifications have been explored. It was shown that the set of amino acid residues susceptible to oxidative attack and the degree of oxidation of these residues in FXIII-A 2 of non-activated pFXIII, pFXIII activated by Ca 2+ and fully activated pFXIII treated with thrombin and Ca 2+ significantly differ. The obtained data enable one to postulate that in the process of the proenzyme conversion into FXIII-A 2 *, new earlier-unexposed amino acid residues become available for the oxidizer while some of the initially surface-exhibited residues are buried within the protein globule., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Ivacaftor is generally safe and effective in patients aged 2 years and older who have cystic fibrosis and specific CFTR mutations. We assessed its use in children aged 12 to <24 months., Methods: The ARRIVAL study is a phase 3, single-arm, two-part, multicentre study. Eligible children were aged 12 to <24 months at enrolment and had a confirmed diagnosis of cystic fibrosis and a CFTR gating mutation on at least one allele and could participate in one or both parts of the study. Children received 50 mg (bodyweight 7 to <14 kg) or 75 mg (bodyweight ≥14 to <25 kg) ivacaftor orally every 12 h. In study part A, children received ivacaftor for 3 days plus one morning. In study part B, children received 24 weeks of treatment. Children were enrolled into part A at seven sites in Australia (one site), the UK (one), and the USA (five) and into part B at 13 sites in Australia (two sites), Canada (one), the UK (three), and the USA (seven). Primary endpoints were pharmacokinetics (part A) and safety (parts A and B) in children who received at least one dose of ivacaftor. Secondary endpoints in part B were pharmacokinetics in children who received at least one dose of ivacaftor and absolute change from baseline in sweat chloride concentration. We also explored changes in growth parameters and markers of pancreatic function. This study is registered with ClinicalTrials.gov, number NCT02725567., Findings: Children aged 12 to <24 months were enrolled between Aug 25, 2016, and Nov 1, 2017. Seven children were enrolled in part A, of whom five received 50 mg and two received 75 mg ivacaftor. All completed treatment. Of 19 children enrolled in part B, including one from part A, all received 50 mg ivacaftor and 18 completed treatment (one withdrew because of difficulty with blood draws). All children received at least one dose of ivacaftor. Pharmacokinetics indicated exposure was similar to that in children aged 2 to <6 years and adults. No children discontinued because of adverse events or safety findings. In part A, three (43%) of seven children had treatment-emergent adverse events, all of which were mild and deemed not to be or unlikely to be related to ivacaftor. By 24 weeks in part B, treatment-emergent adverse events had been reported in 18 (95%) of 19 children, of which most were mild or moderate and the most frequent was cough (14 [74%] children). Two children in part B had four serious adverse events: one had constipation (possibly related to ivacaftor), distal intestinal obstruction syndrome, and eczema herpeticum, and one had persistent cough, all needing hospital admission. In five (28%) of 18 children aspartate or alanine aminotransferase concentrations rose to more than three times the upper limit of normal (to more than eight times in two children with concurrent infections). At week 24, the mean absolute change from baseline in sweat chloride concentration was -73·5 (SD 17·5) mmol/L. Growth parameters for age were normal at baseline and at week 24. At week 24, concentrations of faecal elastase-1 had increased and concentrations of immunoreactive trypsinogen had decreased from baseline. Mean serum lipase and amylase were raised at baseline and rapidly decreased after treatment was started., Interpretation: Ivacaftor was generally safe and well tolerated in children aged 12 to <24 months for up to 24 weeks and was associated with rapid and sustained reductions in sweat chloride concentrations. Improvements in biomarkers of pancreatic function suggest that ivacaftor preserves exocrine pancreatic function if started early. The study is continuing in infants younger than 12 months., Funding: Vertex Pharmaceuticals Incorporated., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: While the emergence of chronic and mucoid Pseudomonas aeruginosa (Pa) infection are both associated with poorer outcomes among CF patients, their relationship is poorly understood. We examined the longitudinal relationship of incident, chronic and mucoid Pa in a contemporary, young CF cohort in the current era of Pa eradication therapy., Methods: This retrospective cohort was comprised of patients in the U.S. CF Foundation Patient Registry born 2006-2015, diagnosed before age 2, and with at least 3 respiratory cultures annually. Incidence and age-specific prevalence of Pa infection stages (initial and chronic [≥ 3Pa+cultures in prior year]) and of mucoid Pa were summarized. Transition times and the interaction between Pa stage and acquisition of mucoid Pa were examined via Cox models., Results: Among the 5592 CF patients in the cohort followed to a mean age of 5.5years, 64% (n=3580) acquired Pa. Of those, 13% (n=455) developed chronic Pa and 17% (n=594) cultured mucoid Pa. Among those with mucoid Pa, 36% (211/594) had it on their first recorded Pa+culture, while mucoid Pa emerged at or after entering the chronic stage in 12% (73/594). Mucoidy was associated with significantly increased risk of transition to chronic Pa infection (HR=2.59, 95% CI 2.11, 3.19)., Conclusions: Two-thirds of early-diagnosed young children with CF acquired Pa during a median 5.6years of follow up, among whom 13% developed chronic Pa and 17% acquired mucoid Pa. Contrary to our hypothesis, 87% of young children who developed mucoid Pa did so before becoming chronically infected., (Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Background: The Infant Study of Inhaled Saline (ISIS) in CF was the first multicenter clinical trial to utilize infant pulmonary function tests (iPFTs) as an endpoint., Methods: Secondary analysis of ISIS data was conducted in order to assess feasibility of iPFT measures and their associations with respiratory symptoms. Standard deviations were calculated to aid in power calculations for future clinical trials., Results: Seventy-three participants enrolled, 70 returned for the final visit; 62 (89%) and 45 (64%) had acceptable paired functional residual capacity (FRC) and raised volume measurements, respectively. Mean baseline FEV0.5, FEF75 and FRC z-scores were 0.3 (SD: 1.2), -0.2 (SD: 2.0), and 1.8 (SD: 2.0)., Conclusions: iPFTs are not appropriate primary endpoints for multicenter clinical trials due to challenges of obtaining acceptable data and near-normal average raised volume measurements. Raised volume measures have potential to serve as secondary endpoints in future clinical CF trials., (Copyright © 2015 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Background: Ivacaftor has been shown to be a safe, effective treatment for cystic fibrosis in patients aged 6 years or older with a CFTR gating mutation. We aimed to assess the safety, pharmacokinetics, and pharmacodynamics of ivacaftor in children aged 2-5 years., Methods: In the two-part KIWI study, we enrolled children aged 2-5 years weighing 8 kg or more with a confirmed diagnosis of cystic fibrosis and a CFTR gating mutation on at least one allele from 15 hospitals in the USA, UK, and Canada. Participants received oral ivacaftor 50 mg (if bodyweight <14 kg) or 75 mg (if bodyweight ≥14 kg) every 12 h for 4 days in part A (to establish the short-term safety of doses for subsequent assessment in part B), and then for 24 weeks in part B (to assess safety and longer-term pharmacodynamics). Children could participate in both or just one part of the study. Primary outcomes were pharmacokinetics and safety, analysed in all patients who received at least one dose of ivacaftor. Secondary outcomes were absolute change from baseline in sweat chloride concentrations and bodyweight, body-mass index (BMI), and height Z scores, and pharmacokinetic parameter estimation of ivacaftor. This study is registered with ClinicalTrials.gov, number NCT01705145., Findings: Between Jan 8, 2013, and March 1, 2013, nine patients were enrolled onto part A of the study, all of whom completed the 4 day treatment period, and eight of whom took part in part B. Between June 28, 2013, and Sept 26, 2013, 34 patients were enrolled in part B, 33 of whom completed the 24 week treatment period. All patients received at least one dose of ivacaftor. Results of ivacaftor pharmacokinetics suggested that exposure was similar to that reported in adults (median Cmin were 536 ng/mL for the 50 mg dose; 580 ng/mL for the 75 mg dose; median ivacaftor AUC values were 9840 ng × h/mL and 10 200 ng × h/mL, respectively). Common adverse events in part B included cough (in 19 [56%] of 34 patients) and vomiting (in ten [29%]). Five (15%) patients had liver function test (LFT) results that were more than eight times higher than the upper limit of normal, four of whom had study drug interrupted, and one of whom had study drug discontinued. Six (18%) of 34 patients had seven serious adverse events; a raised concentration of transaminases was the only serious adverse event regarded as related to ivacaftor and the only adverse event that resulted in study treatment discontinuation. At week 24, in patients for whom we had data, sweat chloride had changed from baseline by a mean of -46·9 mmol/L (SD 26·2, p<0·0001), weight Z score by 0·2 (0·3; p<0·0001), BMI Z score by 0·4 (0·4, p<0·0001), and height Z score by -0·01 (0·3; p=0·84)., Interpretation: Ivacaftor at doses of 50 mg and 75 mg seems to be safe in children aged 2-5 years with cystic fibrosis with a gating mutation followed up for 24 weeks, although the frequency of elevated LFTs suggests that monitoring should be frequent in young children, particularly those with a history of elevated LFTs. Results of an ongoing extension study assessing durability of these effects and longer-term safety are warranted., Funding: Vertex Pharmaceuticals Incorporated., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: There is an urgent need to evaluate treatments for young children with cystic fibrosis (CF); however, efforts have been hampered by a lack of reliable, practical endpoints. To examine whether a patient-reported outcome could be reliable in children 4 to 60 months of age, we assessed the psychometric properties of the modified Parent Cystic Fibrosis Questionnaire--Revised (CFQ-R) using data from the Infant Study of Inhaled Saline (ISIS). We also characterized patterns of symptom presentation and daily functioning in children in this age range to inform future measure development., Methods: Parents (N=314) completed the CFQ-R and Treatment Adherence Questionnaire (TAQ) at five quarterly visits, as well as a weekly Parent Symptom Diary., Results: The Parent CFQ-R demonstrated good construct validity and adequate internal consistency (α's .58-.75). Associations with age, TAQ, and Parent Symptom Diary were observed. The Treatment Burden scale demonstrated responsiveness to change., Conclusions: Parents were reliable observers of young children's symptoms and daily functioning, and PROs show promise for this age group. Research is needed to identify key symptoms in infants and young children with CF, and to develop a parent proxy PRO according to FDA/EMA guidelines., (Copyright © 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Background: Motile cilia dysfunction causes primary ciliary dyskinesia (PCD), situs inversus totalis (SI), and a spectrum of laterality defects, yet the prevalence of laterality defects other than SI in PCD has not been prospectively studied., Methods: In this prospective study, participants with suspected PCD were referred to our multisite consortium. We measured nasal nitric oxide (nNO) level, examined cilia with electron microscopy, and analyzed PCD-causing gene mutations. Situs was classified as (1) situs solitus (SS), (2) SI, or (3) situs ambiguus (SA), including heterotaxy. Participants with hallmark electron microscopic defects, biallelic gene mutations, or both were considered to have classic PCD., Results: Of 767 participants (median age, 8.1 years, range, 0.1-58 years), classic PCD was defined in 305, including 143 (46.9%), 125 (41.0%), and 37 (12.1%) with SS, SI, and SA, respectively. A spectrum of laterality defects was identified with classic PCD, including 2.6% and 2.3% with SA plus complex or simple cardiac defects, respectively; 4.6% with SA but no cardiac defect; and 2.6% with an isolated possible laterality defect. Participants with SA and classic PCD had a higher prevalence of PCD-associated respiratory symptoms vs SA control participants (year-round wet cough, P < .001; year-round nasal congestion, P = .015; neonatal respiratory distress, P = .009; digital clubbing, P = .021) and lower nNO levels (median, 12 nL/min vs 252 nL/min; P < .001)., Conclusions: At least 12.1% of patients with classic PCD have SA and laterality defects ranging from classic heterotaxy to subtle laterality defects. Specific clinical features of PCD and low nNO levels help to identify PCD in patients with laterality defects., Trial Registry: ClinicalTrials.gov; No.: NCT00323167; URL: www.clinicaltrials.gov.

Rationale: Pseudomonas aeruginosa (Pa) serology could potentially be a useful adjunct to respiratory culture methods for the detection of initial or early Pa infection in patients with cystic fibrosis (CF)., Objective: To evaluate the utility of Pa serology to predict Pa isolation from respiratory (generally oropharyngeal) cultures in the subsequent 6 or 12 months among young children with CF from whom Pa had never been previously cultured. Pa serology was also evaluated in a group of healthy controls., Methods: Children ≤ 12 years of age without prior isolation of Pa from respiratory cultures participating in the Early Pseudomonal Infection Control EPIC Observational Study (EPIC OBS) had annual serum samples for measurement of antibodies against alkaline protease, elastase and exotoxin A using a commercial kit; controls had a single serum sample. Logistic regression with generalized estimating equations was used to characterize associations between log10 serum antibody titers and first isolation of Pa from a respiratory culture within the subsequent 6 or 12 months, with adjustment for sex and age. Receiver operating characteristic curves were used to optimize antibody titer cutpoints by age group. The diagnostic properties of each antibody were estimated using these optimized cutpoints., Results: Pa serology was evaluated in 582 children with CF (2084 serum samples) and 94 healthy controls. There was substantial overlap between serum antibody titers among controls, CF patients who did not acquire Pa (N = 261) and CF patients who did acquire Pa (N = 321). The maximum positive predictive value for first Pa positive culture within the ensuing 6 months was 76.2% and maximum negative predictive value was 72.1% for any antigen or combination of antigens; values were similar for 12 months., Conclusions: Pa serology does not appear useful for predicting first Pa positive oropharyngeal culture among young CF patients., (Copyright © 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Background: The Quanjer et al. Global Lung Function Initiative (GLI)-2012 multi-ethnic all-age reference equations for spirometry are endorsed by all major respiratory societies and are the new gold standard. Before the GLI equations are implemented for use in CF patients, the impact of changing equations from those currently used needs to be better understood., Methods: Annual review data submitted to the UK CF Trust Registry between 2007 and 2011 were used to calculate %predicted FEV1, FVC and FEV1/FVC using three widely used reference equations (Wang-Hankinson and Knudson) and the new GLI-2012 equations., Results: Overall, Knudson and Wang equations overestimated %predicted values in paediatric patients, such that a greater proportion of patients had lung function values in the normal range. Within individual patients, the impact of switching equations varied greatly depending on the patients' age, and which equations were used., Conclusions: A unified approach to interpreting spirometric lung function measurements would help facilitate more appropriate comparison both within and between centres and countries. Interpretation of longitudinal measurements using a continuous reference equation across all-ages, like the GLI, may further improve our understanding of CF lung disease., (Copyright © 2013 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Pseudomonas aeruginosa, the principal respiratory pathogen in cystic fibrosis (CF) patients, is ubiquitous in the environment. Initial P. aeruginosa isolates in CF patients are generally environmental in nature. However, little information regarding seasonality of P. aeruginosa acquisition is available. We conducted a retrospective study to evaluate the seasonality of initial P. aeruginosa acquisition in young children with CF in the USA using the Cystic Fibrosis Foundation National Patient Registry from 2003 to 2009. Additionally, we assessed whether seasonal acquisition varied by climate zone. A total of 4123 children met inclusion criteria and 45% (n = 1866) acquired P. aeruginosa during a mean 2.0 years (SD 0.2 years) of follow up. Compared with winter, increased P. aeruginosa acquisition was observed in summer (incidence rate ratio (IRR): 1.22; 95% CI: 1.07-1.40) and autumn (IRR: 1.34; 95% CI: 1.18-1.52), with lower acquisition observed in spring (IRR: 0.81; 95% CI: 0.70-0.94). Seasonal variations in P. aeruginosa acquisition rates in the temperate and continental climate zones were similar to those in the overall cohort. In contrast, no significant seasonal effect was observed in the dry climate zone. In a corresponding analysis, no seasonal difference was observed in the rate of acquisition of Staphylococcus aureus, another common CF respiratory pathogen. These results provide preliminary support that climatic factors may be associated with initial P. aeruginosa acquisition in CF patients. Investigation and identification of specific risk factors, as well as awareness of seasonal variation, could potentially inform clinical recommendations including increased awareness of infection control and prevention strategies., (© 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.)

Background: In a chronic disease setting such as cystic fibrosis (CF), antibiotics are often prescribed for emergent symptoms and it is unclear whether this affects endpoints in a clinical trial. Pulmonary exacerbations (PEs) are defined episodes of acute worsening and a key clinical efficacy measure in CF. Our hypothesis was that acute antibiotics given for illnesses not meeting the PE definition may alter estimates of treatment effect that do not account for this antibiotic use., Methods: A randomized, placebo-controlled trial of azithromycin (AZ) including 260 participants with CF was utilized for this study. PEs were defined using a priori criteria. Physician initiated antibiotic therapy (PIT) not meeting the PE endpoint was characterized and its impact on treatment effect assessed., Results: 40% (104/260) of participants were prescribed 188 courses of PIT in the absence of a PE; 19% (25/129) of placebo and 10% (13/131) of AZ participants received ≥2 courses of PIT and never fulfilled the PE definition (9% difference, 95% confidence interval: 1%, 18%, p = 0.04). Accounting for PIT through use of a composite endpoint including time to PE or need for repeated PIT altered treatment effect estimates (a 56% reduction in the event rate comparing AZ to placebo [p < 0.0001] as compared to a 50% reduction not accounting for PIT [p = 0.003])., Conclusion: PIT is common in CF and may impact treatment effect estimates. Optimization of the PE endpoint to include meaningful events necessitating treatment may improve our ability to conduct efficient trials by reducing the sample size 30-50%, ultimately enabling rapid evaluation of new therapies., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background: The prognostic value of Pseudomonas aeruginosa serology for antibiotic therapy in cystic fibrosis patients is not well understood., Methods: Using five antigens from two ELISAs, we assessed whether positive serology in CF patients participating in the multi-center Early Pseudomonas Infection in Children (EPIC) trial would predict treatment failure, time to pulmonary exacerbation and risk for recurrent P. aeruginosa isolation post eradication., Results: Baseline positive P. aeruginosa serology was not significantly associated with failure of initial P. aeruginosa eradication measured at week 10 (adjusted for baseline culture) but seropositivity to the antigens alkaline protease and exotoxin A was significantly associated with increased risk for recurrent P. aeruginosa isolation during the 60 week post eradication follow-up period (p=0.003 and p=0.001 respectively). There was no association between baseline seropositivity and time to pulmonary exacerbation., Conclusion: P. aeruginosa serology may complement culture results in clinicians' efforts to successfully monitor recurrence of early P. aeruginosa in CF patients., (Copyright © 2012 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Background: Risk factors for initial Pseudomonas aeruginosa (Pa) acquisition, particularly environmental exposures, are poorly understood. We aimed to identify such risk factors in order to inform prevention strategies and identify high-risk populations., Methods: The study cohort included all participants in the U.S. EPIC Observational Study who had no prior Pa-positive respiratory cultures (N=889). Cox proportional hazard models were used to test the effects of factors on age at first Pa-positive respiratory culture., Results: Cystic fibrosis (CF) genotype functional class had an important effect on age at initial Pa acquisition (hazard ratio (HR) comparing minimal to residual CFTR function 2.87 (95% CI 1.88, 4.39)). None of the modifiable risk factors evaluated, including cigarette smoke, hot tub use, breastfeeding, or daycare, was associated with age at Pa acquisition. Similarly, newborn screening was not associated with age at Pa acquisition (HR 0.85, 95% CI 0.66, 1.09). Key associations were validated in a CF Foundation National Patient Registry replication cohort., Conclusions: Given the ubiquitous presence of Pa in the environment, it may be that many imposed lifestyle changes will have less impact on age at initial Pa acquisition than genetic determinants., (Copyright © 2012 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Objective: To describe the prevalence of the CF pathogens Pseudomonas aeruginosa, Staphylococcus aureus and Haemophilus influenzae in OP cultures from healthy children., Methods: Oropharyngeal (OP) swabs were collected from 100 healthy children ≤18 years of age undergoing a clinically indicated procedure., Results: P. aeruginosa was isolated from the OP swab of one participant, S. aureus from 48 participants (including 4 methicillin-resistant) and H. influenzae from 47 participants. Cultures from 75 participants grew one or more of these organisms (55 grew one, 19 grew 2 and one grew 3 organisms)., Conclusion: P. aeruginosa is rarely recovered from the oropharynx of healthy children ≤18 years of age, while recovery of S. aureus and H. influenzae is common. It is important to understand what the "normal" prevalence of CF pathogens is in the oropharynx in order to aid interpretation of OP cultures in CF patients., (Copyright © 2012 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)