Evolution of cystic fibrosis lung function in the early years:

Effectiveness and safety of elexacaftor/tezacaftor/ivacaftor treatment in children aged 6-11 years with cystic fibrosis in a real-world setting

BACKGROUND

Elexacaftor-tezacaftor-ivacaftor (ETI) is a highly effective cystic fibrosis (CF) transmembrane conductance regulator (CFTR) modulating therapy for people with CF and at least one F508del variant. However, there is limited data about the safety and efficacy of this therapy in pediatric populations and in real-world settings. This study aimed at evaluating the effectiveness, tolerability, and safety of ETI in children with CF.

METHODS

This was a prospective observational study including all children aged 6-11 years who initiated ETI therapy between October 2022 and March 2023 at the Pediatric CF Center of Milan (Italy). Study outcomes included changes in sweat chloride concentration, FEV1, LCI2.5, body mass index (BMI), tolerance, and safety. Mean changes in study outcomes from baseline through 24 weeks were estimated using mixed-effects regression models.

RESULTS

The study included 34 children with CF (median age: 8.3 years). At Week 12, we observed an average decrease in LCI2.5 of 2.3 units (95% confidence interval [CI]: -3.1; -1.5). At Week 24, sweat chloride concentration decreased by 63 mEq/L (95% CI: -69; -58), FEV1 increased by 8.8 percentage point (95% CI: 3.7; 13.9) and BMI increased by 0.15 standard deviation scores (95% CI: 0.04; 0.25). Skin rashes appeared in 6 patients which spontaneously resolved within a few days. One month after treatment initiation, one patient experienced an elevation in liver function test results, which subsequently decreased during follow-up visits without necessitating discontinuation of therapy.

CONCLUSIONS

Our data indicate that ETI therapy is well tolerated by children with CF and is effective in improving signs of lung function abnormalities from early childhood.

Elevated Prostaglandin E2 Synthesis Is Associated with Clinical and Radiological Disease Severity in Cystic Fibrosis

Background: Previous studies found high but very variable levels of tetranor-PGEM and PGDM (urine metabolites of prostaglandin (PG) E2 and PGD2, respectively) in persons with cystic fibrosis (pwCF). This study aims to assess the role of cyclooxygenase COX-1 and COX-2 genetic polymorphisms in PG production and of PG metabolites as potential markers of symptoms' severity and imaging findings. Methods: A total of 30 healthy subjects and 103 pwCF were included in this study. Clinical and radiological CF severity was evaluated using clinical scoring methods and chest computed tomography (CT), respectively. Urine metabolites were measured using liquid chromatography/tandem mass spectrometry. Variants in the COX-1 gene (PTGS1 639 C>A, PTGS1 762+14delA and COX-2 gene: PTGS2-899G>C (-765G>C) and PTGS2 (8473T>C) were also analyzed. Results: PGE-M and PGD-M urine concentrations were significantly higher in pwCF than in controls. There were also statistically significant differences between clinically mild and moderate disease and severe disease. Patients with bronchiectasis and/or air trapping had higher PGE-M levels than patients without these complications. The four polymorphisms did not associate with clinical severity, air trapping, bronchiectasis, or urinary PG levels. Conclusions: These results suggest that urinary PG level testing can be used as a biomarker of CF severity. COX genetic polymorphisms are not involved in the variability of PG production.

Pulmonary Function Tests in the Evaluation of Early Lung Disease in Cystic Fibrosis

BACKGROUND

Properly evaluating respiratory system dysfunction is essential in children with cystic fibrosis (CF). This prospective study aimed to assess the course of early lung disease based on multiple breath nitrogen washout (MBNW), impulse oscillometry (IOS), and conventional techniques, such as spirometry and body plethysmography.

METHODS

Over a 2 year recruitment period, subjects with CF aged 7-18 performed pulmonary function tests (PFTs). Moreover, the nutritional and microbiological status, frequency of pulmonary exacerbations (PExs), and patients' health-related quality of life (HRQoL) were assessed.

RESULTS

The mean age of the children (n = 69) was 14.09 ± 3.26 years; F/M 37/32. Spirometry-based diagnoses of normal lung function (forced expiratory volume in 1 s, FEV₁ ≥ 90%pred), mild (FEV₁ 70-89%pred) and moderate (FEV₁ 40-69%pred) lung diseases were established in 34 (49.3%), 25 (36.2%), and 10 (14.5%) patients, respectively. An elevated lung clearance index (LCI > 6.98) was observed in 85% of the subjects with normal FEV₁. The presence of Pseudomonas aeruginosa infection (n = 16) and the number of PExs treated with IV antibiotics were associated with significantly worse PFT results.

CONCLUSIONS

MBNW and IOS are more helpful tools than conventional techniques in assessing early lung disease in CF. LCI is a more useful parameter for detecting functional abnormalities than FEV₁ in school-age children.

Does newborn screening improve early lung function in cystic fibrosis?

Despite evidence showing an improvement in nutritional outcomes following diagnosis by newborn screening (NBS) for cystic fibrosis (CF), the impact on pulmonary outcomes has been less clear. In this review the approaches to measurement of early lung function and knowledge gained from NBS CF cohorts will be described. Studies which have compared outcomes in those diagnosed by NBS to those diagnosed following symptomatic presentation will be presented. Compiling the evidence base used to evaluate the impact of NBS on pulmonary outcomes has been complicated by improvements in clinical management, infection control practices, as well as public health interventions (such as tobacco smoking bans in public places) that have evolved substantially over recent decades. Forced expiratory volumes have been used as the main outcome but it is important not to draw conclusions for 'early lung function' from tests such as spirometry alone, which lack sensitivity in early lung disease. There is, at present, insufficient evidence to draw firm conclusions about the effect of NBS on early lung function. In an era of highly effective treatments targeting the underlying molecular defect responsible for CF, future opportunities for early initiation of treatment may mean that the impact of NBS on early lung function may yet to be realised.

A multimodal approach to detect and monitor early lung disease in cystic fibrosis

Introduction: In the early stages, lung involvement in cystic fibrosis (CF) can be silent, with disease progression occurring in the absence of clinical symptoms. Irreversible airway damage is present in the early stages of disease; however, reliable biomarkers of early damage due to inflammation and infection that are universally applicable in day-to-day patient management have yet to be identified.Areas covered: At present, the main methods of detecting and monitoring early lung disease in CF are the lung clearance index (LCI), computed tomography (CT), and magnetic resonance imaging (MRI). LCI can be used to detect patients who may require more intense monitoring, identify exacerbations, and monitor responses to new interventions. High-resolution CT detects structural alterations in the lungs of CF patients with the best resolution of current imaging techniques. MRI is a radiation-free imaging alternative that provides both morphological and functional information. The role of MRI for short-term follow-up and pulmonary exacerbations is currently being investigated.Expert opinion: The roles of LCI and MRI are expected to expand considerably over the next few years. Meanwhile, closer collaboration between pulmonology and radiology specialties is an important goal toward improving care and optimizing outcomes in young patients with CF.

Lung function deterioration in school children with cystic fibrosis

INTRODUCTION

Lung disease in cystic fibrosis (CF) begins early in life but the capabilities for detecting abnormalities of pulmonary dysfunction in children remain limited.

OBJECTIVE

The study aimed to evaluate the early progression of lung function by the analysis of pulmonary hyperinflation, ventilation inhomogeneity (VI), trapped gas and airway obstruction with age.

METHODS

One hundred CF children aged 7 to 18, divided into two groups aged 7 to 12 (n = 40) and 13 to 18 (n = 60), were enrolled. Patients performed multiple-breath nitrogen washout (MBNW) tests and plethysmography for measurements of lung clearance index (LCI), functional residual capacity (FRC_pleth , FRC_MBNW ), volume of trapped gas (V_T ), total resistance, and effective and specific effective airway resistance (R_eff , sR_eff ).

RESULTS

We obtained a positive correlation of FRC_pleth , FRC_MBNW , and LCI with age. A linear correlation between FRC_MBNW and FRC_pleth (P < .0001) was observed. VI was higher in the group of older patients (9.79 in the group aged 7-12 and 11.67 in the group aged 13-18). An increased effective specific airway resistance >2 (z-score) was present in 58% of all subjects (50% and 63.3%, respectively). Pulmonary hyperinflation (FRC_pleth >2 z-score) was observed in 33% of all patients: 25% and 36.6%, respectively. Trapped gas (V_T  > 2 z-score) was present in 18% of all children: 30% and 10%, respectively.

CONCLUSION

A gradual decline in lung function is associated with an increase in VI, airway obstruction, pulmonary hyperinflation and development of trapped gas. In children who cannot perform either spirometry or plethysmography, MBNW can deliver a measurement of LCI connecting with VI as well as FRC_MBNW to indicate indirectly the increase of hyperinflation.

High-resolution computed tomography findings in young infants with cystic fibrosis detected by newborn screening

OBJECTIVE

High-resolution computed tomography (HRCT) allows the early detection of pathological changes in the lung structure, and reproducible scoring systems can be used to quantify chest computed tomography (CT) findings in patients with cystic fibrosis (CF). The aim of the study was to describe early HRCT findings according to a validated scoring system in infants with CF diagnosed by newborn screening (NBS).

METHODS

This cross-sectional study included infants with CF diagnosed by NBS who were born between January 2013 and January 2017 and who underwent HRCT scanning within the first year after diagnosis when they were clinically stable. The CT scans were evaluated using the modified Bhalla score.

RESULTS

Thirty-two subjects underwent HRCT scanning. The mean total-modified Bhalla score was 3.6±2.1, and 93.8% of the scans were abnormal. Pseudomonas aeruginosa airway colonization was associated with increased modified Bhalla score values. Bronchial wall thickening was the most common feature (90.6%), followed by bronchial collapse/consolidation (59.4%), mosaic attenuation/perfusion (50%), bronchiectasis (37.5%) and mucus plugging (15.6%). Bronchial wall thickening was diffuse in most of the patients.

CONCLUSION

A substantial proportion of infants diagnosed with CF after detection by NBS already showed evidence of lung disease. P. aeruginosa colonization was associated with increased Bhalla scores, highlighting the importance of this CF pathogen in early structural lung disease. The presence of bronchial wall thickening at such a young age may reflect the presence of airway inflammatory processes. The detection and quantification of structural abnormalities with the modified Bhalla score may aid in the identification of lung disease before it is clinically apparent.

Using Newborn Sequencing to Advance Understanding of the Natural History of Disease

A significant portion of newborns cared for in the neonatal intensive care unit or other ICUs, such as the cardiac ICU, have a medical condition with a genetic component, including congenital malformations, the leading cause of death in the NICU. In many cases, however, it is not clear which condition the child has or what can be done to help him or her. Genomic sequencing of sick newborns has the potential to bypass the prolonged journey to a diagnosis, improving the medical care of individual infants. Sequencing also has the potential to benefit others beyond the child whose genome is sequenced and his or her immediate family. Sequence data from sick newborns will expand medicine's understanding of genetic diseases, leading to improvements in clinicians' ability to counsel family and to provide even more targeted care. Not only will more frequent use of sequencing lead to discovery of new genes; it will also provide unique insights into the full spectrum of known Mendelian genetic diseases, so-called phenotypic expansion, when a gene previously recognized as associated with a phenotype is found to be associated with an expanded set of clinical features. Genetic and environmental changes that modify the expression of a genetic disease may also be elucidated.

Pulmonary function deficits in newborn screened infants with cystic fibrosis managed with standard UK care are mild and transient

With the advent of novel designer molecules for cystic fibrosis (CF) treatment, there is huge need for early-life clinical trial outcomes, such as infant lung function (ILF). We investigated the degree and tracking of ILF abnormality during the first 2 years of life in CF newborn screened infants.Forced expiratory volume in 0.5 s (FEV_0.5), lung clearance index (LCI) and plethysmographic functional residual capacity were measured at ∼3 months, 1 year and 2 years in 62 infants with CF and 34 controls.By 2 years there was no significant difference in FEV_0.5 z-score between CF and controls, whereas mean LCI z-score was 0.81 (95% CI 0.45-1.17) higher in CF. However, there was no significant association between LCI z-score at 2 years with either 3-month or 1-year results. Despite minimal average group changes in any ILF outcome during the second year of life, marked within-subject changes occurred. No child had abnormal LCI or FEV_0.5 on all test occasions, precluding the ability to identify "high-risk" infants in early life.In conclusion, changes in lung function are mild and transient during the first 2 years of life in newborn screened infants with CF when managed according to a standardised UK treatment protocol. Their potential role in tracking disease to later childhood will be ascertained by ongoing follow-up.

Elevated lung clearance index in infants with cystic fibrosis shortly after birth

It is not known at what age lung function impairment may arise in children with cystic fibrosis (CF). We assessed lung function shortly after birth in infants with CF diagnosed by newborn screening.We performed infant lung function measurements in a prospective cohort of infants with CF and healthy controls. We assessed lung clearance index (LCI), functional residual capacity (FRC) and tidal breathing parameters. The primary outcome was prevalence and severity of abnormal lung function (±1.64 z-scores) in CF.We enrolled 53 infants with CF (mean age 7.8 weeks) and 57 controls (mean age 5.2 weeks). Compared to controls, LCI and FRC were elevated (mean difference 0.30, 95% CI 0.02-0.60; p=0.034 and 14.5 mL, 95% CI 7.7-21.3 mL; p<0.001, respectively), while ratio of time to peak tidal expiratory flow to expiratory time was decreased in infants with CF. In 22 (41.5%) infants with CF, either LCI or FRC exceeded 1.64 z-scores; three infants had both elevated LCI and FRC.Shortly after birth, abnormal lung function is prevalent in CF infants. Ventilation inhomogeneity or hyperinflation may serve as noninvasive markers to monitor CF lung disease and specific treatment effects, and could thus be used as outcome parameters for future intervention studies in this age group.

Early Lung Disease in Infants and Preschool Children with Cystic Fibrosis. What Have We Learned and What Should We Do about It?

The past decade has seen significant advances in understanding of the pathogenesis and progression of lung disease in cystic fibrosis (CF). Pulmonary inflammation, infection, and structural lung damage manifest very early in life and are prevalent among preschool children and infants, often in the absence of symptoms or signs. Early childhood represents a pivotal period amenable to intervention strategies that could delay or prevent the onset of lung damage and alter the longer-term clinical trajectory for individuals with CF. This review summarizes what we have learned about early lung disease in children with CF and discusses the implications for future clinical practice and research.

Best practices in the treatment of early cystic fibrosis lung disease

For many years, management of cystic fibrosis (CF) lung disease was focused on symptomatic treatment of chronic lung infection, which is characterized by cough and sputum production, leading to progressive lung damage. With increasing survival and better knowledge of the pathogenesis of CF lung disease, it has become clear that treatment has to start very early because lung damage occurs in young patients, often before obvious symptoms appear. The arrival of new cystic fibrosis transmembrane conductance-regulator (CFTR)-correcting therapies will bring more opportunities to prevent the disease, apart from only treating chronic lung infection. In this review, a summary of the current knowledge of early CF lung disease is provided, based on animal model studies, as well as on data obtained from well structured follow-up programs after newborn screening (NBS). The most important clinical guidelines for treating young CF patients are also summarized.

Diagnosis and early life risk factors for bronchiectasis in cystic fibrosis: a review

INTRODUCTION

Lung disease in cystic fibrosis begins in early life with neutrophil-dominated inflammation and infection, is progressive and results in structural lung damage characterised by bronchial dilation and bronchiectasis. Preventative strategies must be employed in early life but require a better understanding of how bronchiectasis develops.

AREAS COVERED

In this review we have addressed the diagnosis and early life risk factors for bronchiectasis in young children with cystic fibrosis. A systematic review was not performed and the literature reviewed was known to the authors. Expert commentary: Bronchiectasis represents a process of progressive dilatation and damage of airway walls and is traditionally considered to be irreversible. Diagnosis is primarily by detecting a bronchial:arterial ratio of >1 on chest CT scan. Lung volume has a greater influence on airway diameter than on arterial making control of lung volume during scanning critical. Early life risk factors for the onset and progression bronchiectasis include: severe cystic fibrosis genotype; neutrophilic inflammation with free neutrophil elastase activity in the lung; and pulmonary infection. Bronchiectasis develops in the majority of children before they reach school age despite the best current therapy. To prevent bronchiectasis novel therapies are going to have to be given to infants.