Cystic fibrosis-related diabetes onset can be predicted using biomarkers measured at birth.

PURPOSE: Cystic fibrosis (CF), caused by pathogenic variants in the CF transmembrane conductance regulator (CFTR), affects multiple organs including the exocrine pancreas, which is a causal contributor to cystic fibrosis-related diabetes (CFRD). Untreated CFRD causes increased CF-related mortality whereas early detection can improve outcomes. METHODS: Using genetic and easily accessible clinical measures available at birth, we constructed a CFRD prediction model using the Canadian CF Gene Modifier Study (CGS; n = 1,958) and validated it in the French CF Gene Modifier Study (FGMS; n = 1,003). We investigated genetic variants shown to associate with CF disease severity across multiple organs in genome-wide association studies. RESULTS: The strongest predictors included sex, CFTR severity score, and several genetic variants including one annotated to PRSS1, which encodes cationic trypsinogen. The final model defined in the CGS shows excellent agreement when validated on the FGMS, and the risk classifier shows slightly better performance at predicting CFRD risk later in life in both studies. CONCLUSION: We demonstrated clinical utility by comparing CFRD prevalence rates between the top 10% of individuals with the highest risk and the bottom 10% with the lowest risk. A web-based application was developed to provide practitioners with patient-specific CFRD risk to guide CFRD monitoring and treatment.

Diagnosis of Primary Ciliary Dyskinesia. An Official American Thoracic Society Clinical Practice Guideline.

BACKGROUND: This document presents the American Thoracic Society clinical practice guidelines for the diagnosis of primary ciliary dyskinesia (PCD). TARGET AUDIENCE: Clinicians investigating adult and pediatric patients for possible PCD. METHODS: Systematic reviews and, when appropriate, meta-analyses were conducted to summarize all available evidence pertinent to our clinical questions. Evidence was assessed using the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach for diagnosis and discussed by a multidisciplinary panel with expertise in PCD. Predetermined conflict-of-interest management strategies were applied, and recommendations were formulated, written, and graded exclusively by the nonconflicted panelists. Three conflicted individuals were also prohibited from writing, editing, or providing feedback on the relevant sections of the manuscript. RESULTS: After considering diagnostic test accuracy, confidence in the estimates for each diagnostic test, relative importance of test results studied, desirable and undesirable direct consequences of each diagnostic test, downstream consequences of each diagnostic test result, patient values and preferences, costs, feasibility, acceptability, and implications for health equity, the panel made recommendations for or against the use of specific diagnostic tests as compared with using the current reference standard (transmission electron microscopy and/or genetic testing) for the diagnosis of PCD. CONCLUSIONS: The panel formulated and provided a rationale for the direction as well as for the strength of each recommendation to establish the diagnosis of PCD.

Immunoreactive trypsinogen levels in newborn screened infants with an inconclusive diagnosis of cystic fibrosis.

BACKGROUND: Newborn screening (NBS) for cystic fibrosis (CF) not only identifies infants with a diagnosis of CF, but also those with an uncertain diagnosis of cystic fibrosis (CF), i.e. CF transmembrane conductance regulator (CFTR)-related metabolic syndrome (CRMS) or CF screen positive inconclusive diagnosis (CFSPID). These infants have an uncertain long-term outcome and it is currently unclear around time of diagnosis, which infants are at higher risk of later fulfilling a CF diagnosis. In this study, we hypothesised that immunoreactive trypsinogen (IRT) levels, used in NBS as a marker of pancreatic disease and function, may reflect the degree of CFTR dysfunction in each individual and therefore would help to identify those with CRMS/CSPID who are later at risk for meeting the criteria of CF. METHODS: In this longitudinal, prospective study, infants with CRMS/CFSPID and CF were recruited and followed in 9 CF clinics (Canada and Italy). We compared NBS IRT levels between CF and CRMS/CFSPID, and between children with CRMS/CFSPID→CF and CRMS/CFSPID→CRMS/CFSPID during the period of June 2007 to April 2016. RESULTS: Ninety eight CRMS/CFSPID and 120 CF subjects were enrolled. During the study period, 14 (14.3%) CRMS/CFSPID subjects fulfilled the diagnostic criteria for CF (CRMS/CFSPID→CF), while the diagnosis remained uncertain (CRMS/CFSPID→ CRMS/CFSPID) in 84 (85.7%) subjects. Significantly higher NBS IRT concentrations (ng/ml) were present in CF than CRMS/CFPSID (median (interquartile range): 143.8 (99.8-206.2) vs. 75.0 (61.0-105.9); P < 0.0001). Infants with CRMS/CFSPID→CF (n = 14) had significantly higher NBS IRT concentrations (ng/ml) than CRMS/CFSPID→ CRMS/CFSPID (n = 83) (median (interquartile range): 108.9 (72.3-126.8) vs. 73.7(60.0-96.0); P = 0.02). CONCLUSIONS: Amongst infants who tested positive on NBS for CF, there is a gradation of elevated NBS IRT concentrations. Infants with CF have higher NBS IRT levels than CRMS/CFPSID, and higher NBS IRT concentrations were present in infants with CRMS/CFSPID→CF than CRMS/CFSPID→ CRMS/CFSPID. NBS IRT concentrations, in concert with other factors, may have the potential to predict the likelihood of CF amongst infants with CRMS/CFSPID.

Dornase alfa for cystic fibrosis.

BACKGROUND: Dornase alfa is currently used as a mucolytic to treat pulmonary disease (the major cause of morbidity and mortality) in cystic fibrosis. It reduces mucus viscosity in the lungs, promoting improved clearance of secretions. This is an update of a previously published review. OBJECTIVES: To determine whether the use of dornase alfa in cystic fibrosis is associated with improved mortality and morbidity compared to placebo or other medications that improve airway clearance, and to identify any adverse events associated with its use. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches, handsearching relevant journals and abstracts from conferences. Date of the most recent search of the Group's Cystic Fibrosis Register: 30 November 2015.Clinicaltrials.gov was also searched to identify unpublished or ongoing trials. Date of most recent search: 28 November 2015. SELECTION CRITERIA: All randomised and quasi-randomised controlled trials comparing dornase alfa to placebo, standard therapy or other medications that improve airway clearance. DATA COLLECTION AND ANALYSIS: Authors independently assessed trials against the inclusion criteria; two authors carried out analysis of methodological quality and data extraction. MAIN RESULTS: The searches identified 54 trials, of which 19 (including a total of 2565 participants) met our inclusion criteria. Three additional papers examined the healthcare cost from one of the clinical trials. Fifteen trials compared dornase alfa to placebo or no dornase alfa treatment (2447 participants); two compared daily dornase to hypertonic saline (32 participants); one compared daily dornase alfa with hypertonic saline and alternate day dornase alfa (48 participants); one compared dornase alfa to mannitol and the combination of both drugs (38 participants). Trial duration varied from six days to three years.Compared to placebo, forced expiratory volume at one second improved in the intervention groups, with significant differences at one, three, six months and two years. There was also a significant improvement in lung clearance index at one month. There was a decrease in pulmonary exacerbations compared to placebo in trials of longer duration. The quality of the evidence from placebo-controlled trials was moderate to high for outcomes of lung function and pulmonary exacerbations. Limited, low quality evidence was available for changes in quality of life from baseline. One trial that examined the cost of care, including the cost of dornase alfa, found that the cost savings from dornase alfa offset 18% to 38% of the medication costs.The results for trials comparing dornase alfa to other medications that improve airway clearance (hypertonic saline or mannitol) were mixed, with one trial showing a greater improvement in forced expiratory volume at one second for dornase alfa compared to hypertonic saline, and three trials finding no difference between medications. In the only trial to assess the combination of dornase alfa with another medication compared to dornase alone, there was no benefit seen with the combination of dornase alfa and mannitol. Evidence of dornase alfa compared to other medications was limited and the open-label design of the trials may have induced bias, therefore the quality of the evidence was judged to be low.Dornase alfa did not cause significantly more adverse effects, except voice alteration and rash. AUTHORS' CONCLUSIONS: There is evidence to show that, compared with placebo, therapy with dornase alfa improves lung function in people with cystic fibrosis in trials lasting one month to two years. There was a decrease in pulmonary exacerbations in trials of six months or longer. Voice alteration and rash appear to be the only adverse events reported with increased frequency in randomised controlled trials. There is not enough evidence to firmly conclude if dornase alfa is superior to hyperosmolar agents in improving lung function.

Evaluation of a multidimensional cystic fibrosis transition program: a quality improvement initiative.

The adequate preparation of cystic fibrosis (CF) youth for the transfer from pediatric to adult-based health care services is essential to meet the needs of this changing population. This paper describes the evolution of a transition clinic for patients with CF into a multidimensional quality improvement transition initiative. Three transition interventions (a patient transition clinical pathway; collaboration with the adult clinic; and a tool to measure transfer readiness) were sequentially implemented and evaluated. Each was found to be a valuable addition to a comprehensive transition protocol and today are endorsed as part of transition best practices.

Atypical activation of the unfolded protein response in cystic fibrosis airway cells contributes to p38 MAPK-mediated innate immune responses.

Inflammatory lung disease is the major cause of morbidity and mortality in cystic fibrosis (CF); understanding what produces dysregulated innate immune responses in CF cells will be pivotal in guiding the development of novel anti-inflammatory therapies. To elucidate the molecular mechanisms that mediate exaggerated inflammation in CF following TLR signaling, we profiled global gene expression in immortalized human CF and non-CF airway cells at baseline and after microbial stimulation. Using complementary analysis methods, we observed a signature of increased stress levels in CF cells, specifically characterized by endoplasmic reticulum (ER) stress, the unfolded protein response (UPR), and MAPK signaling. Analysis of ER stress responses revealed an atypical induction of the UPR, characterized by the lack of induction of the PERK-eIF2α pathway in three complementary model systems: immortalized CF airway cells, fresh CF blood cells, and CF lung tissue. This atypical pattern of UPR activation was associated with the hyperinflammatory phenotype in CF cells, as deliberate induction of the PERK-eIF2α pathway with salubrinal attenuated the inflammatory response to both flagellin and Pseudomonas aeruginosa. IL-6 production triggered by ER stress and microbial stimulation were both dependent on p38 MAPK activity, suggesting a molecular link between both signaling events. These data indicate that atypical UPR activation fails to resolve the ER stress in CF and sensitizes the innate immune system to respond more vigorously to microbial challenge. Strategies to restore ER homeostasis and normalize the UPR activation profile may represent a novel therapeutic approach to minimize lung-damaging inflammation in CF.

Efficacy and safety of ivacaftor in patients aged 6 to 11 years with cystic fibrosis with a G551D mutation.

RATIONALE: Ivacaftor (VX-770), a cystic fibrosis transmembrane conductance regulator (CFTR) potentiator, has been shown to improve lung function, pulmonary exacerbation rate, respiratory symptoms, and weight gain compared with placebo in patients with cystic fibrosis aged 12 years or older with a G551D-CFTR mutation. OBJECTIVES: This randomized, double-blind, placebo-controlled trial evaluated ivacaftor in patients with cystic fibrosis aged 6-11 years with a G551D-CFTR mutation on at least one allele. METHODS: Patients were randomly assigned to receive ivacaftor administered orally at 150 mg (n = 26) or placebo (n = 26) every 12 hours for 48 weeks in addition to existing prescribed cystic fibrosis therapies. MEASUREMENTS AND MAIN RESULTS: Despite near-normal mean baseline values in FEV1, patients receiving ivacaftor had a significant increase in percent predicted FEV1 from baseline through Week 24 versus placebo group (treatment effect, 12.5 percentage points; P < 0.001). Effects on pulmonary function were evident by 2 weeks, and a significant treatment effect was maintained through Week 48. Patients treated with ivacaftor gained, on average, 2.8 kg more than those receiving placebo at Week 48 (P < 0.001). The change from baseline through Week 48 in the concentration of sweat chloride, a measure of CFTR activity, with ivacaftor was -53.5 mmol/L (P < 0.001) versus placebo. The incidence of adverse events was similar in the two groups. CONCLUSIONS: In patients who are younger and healthier than those in previously studied populations, ivacaftor demonstrated a significant improvement in pulmonary function, weight, and CFTR activity compared with placebo. Clinical trial registered with www.clinicaltrials.gov (NCT00909727).

Standards for the care of people with cystic fibrosis; establishing and maintaining health.

This is the second 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 establishing and maintaining health. The guidance is produced using an evidence-based framework and with wide stakeholder engagement, including people from the CF community. Authors provided a narrative description of their topic and statements, which were more directive. These statements were reviewed by a Delphi exercise, achieving good levels of agreement from a wide group for all statements. This guidance reinforces the importance of a multi-disciplinary CF team, but also describes developing models of care including virtual consultations. The framework for health is reinforced, including the need for a physically active lifestyle and the strict avoidance of all recreational inhalations, including e-cigarettes. Progress with cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy is reviewed, including emerging adverse events and advice for dose reduction and interruption. This paper contains guidance that is pertinent to all people with CF regardless of age and eligibility for and access to modulator therapy.

High-quality read-based phasing of cystic fibrosis cohort informs genetic understanding of disease modification.

Phasing of heterozygous alleles is critical for interpretation of cis-effects of disease-relevant variation. We sequenced 477 individuals with cystic fibrosis (CF) using linked-read sequencing, which display an average phase block N50 of 4.39 Mb. We use these samples to construct a graph representation of CFTR haplotypes, demonstrating its utility for understanding complex CF alleles. These are visualized in a Web app, CFTbaRcodes, that enables interactive exploration of CFTR haplotypes present in this cohort. We perform fine-mapping and phasing of the chr7q35 trypsinogen locus associated with CF meconium ileus, an intestinal obstruction at birth associated with more severe CF outcomes and pancreatic disease. A 20-kb deletion polymorphism and a PRSS2 missense variant p.Thr8Ile (rs62473563) are shown to independently contribute to meconium ileus risk (p = 0.0028, p = 0.011, respectively) and are PRSS2 pancreas eQTLs (p = 9.5 × 10-7 and p = 1.4 × 10-4, respectively), suggesting the mechanism by which these polymorphisms contribute to CF. The phase information from linked reads provides a putative causal explanation for variation at a CF-relevant locus, which also has implications for the genetic basis of non-CF pancreatitis, to which this locus has been reported to contribute.

Effects of a Pseudomonas aeruginosa eradication policy in a cystic fibrosis clinic.

PURPOSE OF REVIEW: This review is based upon the recent literature regarding eradication of newly acquired infection with Pseudomonas aeruginosa (Psa) in patients with cystic fibrosis (CF) and the economic and other effects of such an early eradication policy in a CF clinic. RECENT FINDINGS: Various Psa eradication protocols which utilize intravenous or aerosol anti-pseudomonal antibiotics, with or without oral antibiotics, have been reported. The recent ELITE trial reported successful eradication of 90% of Psa in selected Psa antibody negative patients after 28 days of tobramycin for inhalation. Another recent report of a protocol based on intravenous antibiotic use reported elimination of 'first growth' Psa in over 96% of all patients, accompanied by decreased chronic Psa infection, decreased anti-Psa treatment costs and decreased hospitalization costs. SUMMARY: The effects of early eradication protocols for Psa have included decreased prevalence of chronic Psa infection, improved patient health and pulmonary function, and decreased hospital and antibiotic costs.

TLR5 as an anti-inflammatory target and modifier gene in cystic fibrosis.

New treatments are needed to improve the health of people with cystic fibrosis (CF). Reducing lung-damaging inflammation is likely to be beneficial, but specific anti-inflammatory targets have not been identified. By combining cellular immunology with a population-based genetic modifier study, we examined TLR5 as an anti-inflammatory target and modifier gene in CF. Using two pairs of human CF and control airway epithelial cells, we demonstrated that the TLR5-flagellin interaction is a major mediator of inflammation following exposure to Pseudomonas aeruginosa. To validate TLR5 as an anti-inflammatory target, we analyzed the disease modifying effects of the TLR5 c.1174C>T single nucleotide polymorphism (rs5744168) in a large cohort of CF patients (n = 2219). rs5744168 encodes a premature stop codon and the T allele is associated with a 45.5-76.3% reduction in flagellin responsiveness (p < 0.0001). To test the hypothesis that reduced TLR5 responsiveness would be associated with improved health in CF patients, we examined the relationship between rs5744168 and two clinical phenotypes: lung function and body weight. Adults with CF carrying the TLR5 premature stop codon (CT or TT genotype) had a higher body mass index than did CF patients homozygous for the fully functional allele (CC genotype) (p = 0.044); however, similar improvements in lung function associated with the T allele were not statistically significant. Although follow-up studies are needed to confirm the impact of TLR5 on nutritional status, this translational research provides evidence that genetic variation in TLR5 resulting in reduced flagellin responsiveness is associated with improved health indicators in adults with CF.

Cystic fibrosis adolescent transition care in Canada: A snapshot of current practice.

Cystic fibrosis (CF) adolescent transition is not a new health care issue, yet progress in many areas associated with the transition process has been slow. In Canada, the status of CF transition has not been previously reported. The aim of the present study was to describe the transition from paediatric to adult health care for CF patients in Canada, specifically: availability of adult CF clinic services; average age of transfer from paediatric to adult CF health care; and existing CF transition practices. Results show that access to appropriate adult CF health care in Canada is universal; however, the availability, quantity and quality of CF transition care vary among CF clinics. Over a four-year period, the number of CF clinics using formal transition protocols almost doubled, but more work remains to be performed.

La transition des adolescents ayant la fibrose kystique (FK) n'est pas un nouveau problème de santé, mais dans de nombreux secteurs, les progrès associés au processus de transition sont lents. Au Canada, on n'a jamais fait de rapport sur la situation de la transition en FK. La présente étude visait à décrire la transition des patients du Canada ayant la FK entre les soins pédiatriques et les soins pour adultes, notamment la disponibilité des services dans les cliniques de FK pour adultes, l'âge moyen du transfert des soins pédiatriques aux soins pour adultes et les pratiques de transition actuelles en FK. Les résultats démontrent qu'au Canada, on jouit d'un accès universel aux soins pour adultes en FK, mais que la disponibilité, la quantité et la qualité des soins de transition varient selon les cliniques. Sur une période de quatre ans, le nombre de cliniques de FK faisant appel à des protocoles de transition officiels a presque doublé, mais il reste beaucoup à faire.

A Phase 3, open-label, 96-week trial to study the safety, tolerability, and efficacy of tezacaftor/ivacaftor in children ≥ 6 years of age homozygous for F508del or heterozygous for F508del and a residual function CFTR variant.

BACKGROUND: Two previous Phase 3 studies ("parent studies") showed that tezacaftor/ivacaftor was generally safe and efficacious for up to 24 weeks in children 6 through 11 years of age with cystic fibrosis (CF) and F508del/F508del (F/F) or F508del/residual function (F/RF) genotypes. We assessed the safety and efficacy of tezacaftor/ivacaftor in an open-label, 96-week extension study. METHODS: This was a Phase 3, 2-part, multicenter, open-label, extension study in children 6 through 11 years of age at treatment initiation (Study VX17-661-116; NCT03537651). The primary endpoint was safety and tolerability. Secondary endpoints were absolute change from baseline in lung clearance index2.5 (LCI2.5), sweat chloride (SwCl) concentration, Cystic Fibrosis Questionnaire-Revised (CFQ-R) respiratory domain score, and body mass index (BMI). RESULTS: One-hundred thirty children enrolled and received ≥ 1 dose of tezacaftor/ivacaftor; 109 completed treatment. Most (n = 129) had ≥ 1 treatment-emergent adverse event (TEAE), the majority of which were mild or moderate in severity and generally consistent with common manifestations of CF. Exposure-adjusted TEAE rates were similar to or lower than those in the parent studies. Five (3.8%) had TEAEs leading to treatment discontinuation. Efficacy results from the parent studies were maintained, with improvements in lung function, SwCl concentration, CFQ­R respiratory domain score, and BMI observed from parent study baseline to Week 96. CONCLUSIONS: Tezacaftor/ivacaftor is generally safe and well tolerated, and treatment effects are maintained for up to 120 weeks. These results support long-term use of tezacaftor/ivacaftor in children ≥ 6 years of age with CF and F/F or F/RF genotypes.

Genetic evidence supports the development of SLC26A9 targeting therapies for the treatment of lung disease.

Over 400 variants in the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) are CF-causing. CFTR modulators target variants to improve lung function, but marked variability in response exists and current therapies do not address all CF-causing variants highlighting unmet needs. Alternative epithelial ion channel/transporters such as SLC26A9 could compensate for CFTR dysfunction, providing therapeutic targets that may benefit all individuals with CF. We investigate the relationship between rs7512462, a marker of SLC26A9 activity, and lung function pre- and post-treatment with CFTR modulators in Canadian and US CF cohorts, in the general population, and in those with chronic obstructive pulmonary disease (COPD). Rs7512462 CC genotype is associated with greater lung function in CF individuals with minimal function variants (for which there are currently no approved therapies; p = 0.008); and for gating (p = 0.033) and p.Phe508del/ p.Phe508del (p = 0.006) genotypes upon treatment with CFTR modulators. In parallel, human nasal epithelia with CC and p.Phe508del/p.Phe508del after Ussing chamber analysis of a combination of approved and experimental modulator treatments show greater CFTR function (p = 0.0022). Beyond CF, rs7512462 is associated with peak expiratory flow in a meta-analysis of the UK Biobank and Spirometa Consortium (p = 2.74 × 10-44) and provides p = 0.0891 in an analysis of COPD case-control status in the UK Biobank defined by spirometry. These findings support SLC26A9 as a therapeutic target to improve lung function for all people with CF and in individuals with other obstructive lung diseases.

Renal function in pediatric cystic fibrosis patients in the first decade of life.

With increasing life expectancy and the need for lung transplantation in the cystic fibrosis (CF) population, there are increasing reports of chronic kidney disease (CKD). However, values for baseline or longitudinal glomerular filtration rate (GFR) as measured by exogenous clearance markers are lacking in this population. Retrospective cross-sectional study in 2 to 18-year-olds cared for at a single CF center who had a GFR measured by plasma disappearance of Technetium-99 m diethylenetriaminepentaacetic acid (mGFR). The primary outcome was evidence of renal dysfunction as defined by CKD stage II or below (mGFR <90 ml/min/1.73 m(2), persistent abnormalities in urinary sediment, abnormal renal imaging). Of 63 patients evaluated, four had apparent renal dysfunction, one demonstrated decreased mGFR, and three others had persistent microscopic hematuria. The mean mGFR was substantially higher (140 ± 24 ml/min/1.73 m(2)) than expected or previously reported for healthy children. We did not demonstrate the presence of significant renal impairment after limited aminoglycoside exposure in the first decade following diagnosis with CF. However, we did document the presence of glomerular hyperfiltration in a significant proportion of our CF patients.

Diagnostic testing of patients suspected of primary ciliary dyskinesia.

RATIONALE: Electron microscopy (EM) of ciliated epithelium is widely used to diagnose primary ciliary dyskinesia (PCD). Ciliary beat frequency (CBF) has been used to screen samples to determine whether EM is indicated. Beat pattern analysis has been advocated as an additional diagnostic test. Neither has been subject to formal review. OBJECTIVES: To determine the ability of CBF and beat pattern analysis to predict EM-diagnosed PCD. METHODS: CBF calculation and beat pattern analysis, using high-speed video microscopy, and EM were performed on nasal tissue from 371 patients consecutively referred to the Leicester Royal Infirmary for diagnostic assessment for PCD. With EM as the "gold standard," receiver operating characteristic (ROC) curves were constructed and sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values were calculated for CBF less than 11 Hz, ciliary dyskinesia score equal to or exceeding 2, at least 90% of ciliated edges beating dyskinetically, and an immotility index equal to or exceeding 10%. MEASUREMENTS AND MAIN RESULTS: PCD was excluded in 270 patients and confirmed in 70 by EM. The sensitivity, specificity, PPV, and NPV for CBF less than 11 Hz were 87.1, 77.2, 50.0, and 95.8%, respectively. These values were higher for ciliary dyskinesia scores equal to or exceeding 2 (92.5, 97.6, 91.2, and 98.0%) and when at least 90% of ciliated edges were dyskinetic (97.1, 95.3, 84.6, and 99.2%). ROCs confirmed that the ciliary dyskinesia score and percentage of dyskinetic edges were superior screening indices compared with CBF and the immotility index. CONCLUSIONS: The use of CBF alone to screen which biopsies should have EM will result in a significant number of missed diagnoses. Ciliary beat pattern analysis is a more sensitive and specific test for PCD with higher PPV and NPV.

Role of transient elastography and APRI in the assessment of pediatric cystic fibrosis liver disease.

Background: Diagnosis and monitoring of cystic fibrosis liver disease (CFLD) is challenging. Transient elastography (TE) is a rapid, non-invasive method for assessing liver fibrosis. Its role in detecting fibrosis in CFLD has only begun to be explored. The aspartate aminotransferase to platelet ratio index (APRI) has been validated as a predictor of hepatic fibrosis in other chronic liver diseases. The purpose of this study was to assess the utility of APRI and TE in identifying liver fibrosis in pediatric CF patients. Methods: Patients aged 2-18 years were recruited from the British Columbia Children's Hospital CF clinic. Patients were determined to have CFLD using standard criteria. Charts were reviewed, and each patient underwent TE. Results: Of the 55 patients included in the study (50.9% male, mean age 11.6 y), 22 (40%) had CFLD. All mean liver enzymes were higher in the CFLD group, notably alanine transaminase (p = 0.031). Mean liver stiffness (LS) and APRI were also higher in the CFLD group (LS: 5.9 versus 4.5 kPa, p = 0.015; APRI: 0.40 versus 0.32, p = 0.119). Linear regression showed a mild positive association between the two (r 2 = 0.386). Conclusions: TE values were higher among CFLD patients and correlated with APRI values, suggesting that these tools may have clinical applications for identifying and following this population. Further research is needed on a larger scale to determine the relative value and clinical utility of TE and APRI among patients with CFLD.

Long-term safety and efficacy of lumacaftor-ivacaftor therapy in children aged 6-11 years with cystic fibrosis homozygous for the F508del-CFTR mutation: a phase 3, open-label, extension study.

BACKGROUND: The safety and efficacy of 24 weeks of lumacaftor-ivacaftor combination therapy in children aged 6-11 years with cystic fibrosis homozygous for the F508del-CFTR mutation was previously shown in two phase 3 studies. Here, we report long-term safety and efficacy data. METHODS: In this phase 3, open-label, multicentre, extension study (study 110), we examined the long-term safety, tolerability, and efficacy of lumacaftor-ivacaftor in children pooled from two phase 3 parent studies (open-label study 011B and randomised, placebo-controlled study 109). The study was conducted at 61 clinics in the USA, Australia, Belgium, Canada, Denmark, France, Germany, Sweden, and the UK. Children with cystic fibrosis homozygous for the F508del-CFTR mutation who had received lumacaftor-ivacaftor or placebo in the parent studies were treated with lumacaftor-ivacaftor for up to 96 weeks; those who had received the combination therapy in the parent studies (the treatment-to-treatment group) received up to 120 weeks of treatment in total. Participants aged 6-11 years at the start of the parent study received lumacaftor 200 mg-ivacaftor 250 mg orally once every 12 h; those aged 12 years or older received lumacaftor 400 mg-ivacaftor 250 mg orally once every 12 h. The primary endpoint was safety and tolerability in all children who had received at least one dose of the study drug. Secondary endpoints included change from baseline in lung clearance index 2·5% (LCI2·5), sweat chloride concentration, body-mass index, and Cystic Fibrosis Questionnaire-Revised respiratory domain score. This extension study is registered with ClinicalTrials.gov, NCT02544451, and has been completed. FINDINGS: The extension study ran from Aug 13, 2015, to Aug 17, 2018. Of 239 children who enrolled in the study and received at least one dose of lumacaftor-ivacaftor, 215 (90%) completed 96 weeks of treatment. Most children (236 [99%] of 239 children) had adverse events that were mild (49 [21%] of 239) or moderate (148 [62%] of 239) in severity, and there was a low rate of adverse events leading to treatment discontinuation. The most frequently reported adverse events were common manifestations or complications of cystic fibrosis, such as cough and pulmonary exacerbation, or were consistent with the known safety profile of lumacaftor-ivacaftor in older children and adults. No new safety concerns were identified with extended lumacaftor-ivacaftor treatment. Children in the placebo-to-treatment group had improvements in efficacy endpoints consistent with those observed in the parent studies. Improvements observed in children treated with lumacaftor-ivacaftor in the parent study were generally maintained in the extension study. INTERPRETATION: Lumacaftor-ivacaftor therapy in children homozygous for F508del-CFTR who initiated treatment at age 6-11 years was generally safe and well tolerated, and efficacy was sustained for up to 120 weeks. These data support the long-term use of lumacaftor-ivacaftor to treat children aged 6 years and older who are homozygous for the F508del-CFTR mutation. FUNDING: Vertex Pharmaceuticals Incorporated.