Return of FEV1 after pulmonary exacerbation in children with cystic fibrosis

Definitions of pulmonary exacerbation in people with cystic fibrosis: a scoping review

BACKGROUND

Pulmonary exacerbations (PExs) are clinically important in people with cystic fibrosis (CF). Multiple definitions have been used for PEx, and this scoping review aimed to identify the different definitions reported in the literature and to ascertain which signs and symptoms are commonly used to define them.

METHODS

A search was performed using Embase, MEDLINE, Cochrane Library, Scopus and CINAHL. All publications reporting clinical trials or prospective observational studies involving definitions of PEx in people with CF published in English from January 1990 to December 2022 were included. Data were then extracted for qualitative thematic analysis.

RESULTS

A total of 14 039 records were identified, with 7647 titles and abstracts screened once duplicates were removed, 898 reviewed as full text and 377 meeting the inclusion criteria. Pre-existing definitions were used in 148 publications. In 75% of papers, an objective definition was used, while 25% used a subjective definition, which subcategorised into treatment-based definitions (76%) and those involving clinician judgement (24%). Objective definitions were subcategorised into three groups: those based on a combination of signs and symptoms (50%), those based on a predefined combination of signs and symptoms plus the initiation of acute treatment (47%) and scores involving different clinical features each with a specific weighting (3%). The most common signs and symptoms reported in the definitions were, in order, sputum production, cough, lung function, weight/appetite, dyspnoea, chest X-ray changes, chest sounds, fever, fatigue or lethargy and haemoptysis.

CONCLUSION

We have identified substantial variation in the definitions of PEx in people with CF reported in the literature. There is a requirement for the development of internationally agreed-upon, standardised and validated age-specific definitions. Such definitions would allow comparison between studies and effective meta-analysis to be performed and are especially important in the highly effective modulator therapy era in CF care.

Update on the diagnosis and management of cystic fibrosis pulmonary exacerbations

Pulmonary exacerbations in people with cystic fibrosis are associated with significant morbidity and reduced quality of life. Pulmonary exacerbation treatment guidelines, published by an expert panel assembled by the Cystic Fibrosis Foundation nearly 15 years ago, were primarily consensus-based as there were several gaps in the evidence base. In particular, limited evidence existed regarding optimal pulmonary exacerbation treatment strategies, including duration of antibiotic therapy, treatment location, antibiotic selection, and the role of systemic corticosteroids. Over the last decade, results from observational studies and large multi-center randomized controlled trials have begun to answer important questions related to pulmonary exacerbation treatment. This review focuses on the diagnosis, etiology, and changing epidemiology of pulmonary exacerbations, and also summarizes the most recent and up-to-date studies describing pulmonary exacerbation treatment. Finally, this review provides consideration for future pulmonary exacerbation research priorities, particularly in the current highly effective modulator therapy era.

Home-spirometry exacerbation profiles in children with cystic fibrosis

BACKGROUND

Pulmonary exacerbations (PEx) are strong predictors of respiratory disease progression in children with cystic fibrosis (CwCF) and may be associated with persistent decreased lung function after acute management. Telemonitoring devices can be used for early detection and monitoring of PEx, but its utility is debated.

RESEARCH QUESTION

Which symptoms and telemonitoring spirometry characterics are related to outcome dynamics following initial PEx management?

METHODS

This retrospective study included CwCF followed at Bordeaux University Hospital, France. All severe PEx episodes treated with intravenous (IV) antibiotics (ATB) between 1 January 2017 and 31 December 2021 in CwCF using home telemonitoring were analyzed. Symptoms and home spirometry data were collected 45 days before and up to 60 days after each IV ATB course. We defined three response profiles based on terciles of baseline forced expiratory volume in 1 s (FEV1 ) recovery.

RESULTS

A total of 346 IV ATB courses for PEx were administered to 65 CwCF during the study period. The drop in FEV1 became significant 8 days before IV ATB initiation. Forty-one percent of IV ATB courses failed to restore baseline FEV1 . The magnitude of FEV1 drop and a greater delay in the initiation of treatment correlated with a low response level. On the 14th day of the IV treatment, a FEV1 recovery less than 94% of baseline was associated with a nonresponder profile.

INTERPRETATION

Home spirometry may facilitate the early recognition of PEx to implement earlier interventions. This study also provides an outcome lung function threshold which identifies low responders to IV ATB.

Respiratory culture growth and 3-years lung health outcomes in children with bronchopulmonary dysplasia and tracheostomies

BACKGROUND

While bacteria identification on respiratory cultures is associated with poor short-term outcomes in children with bronchopulmonary dysplasia (BPD) and tracheostomies, the influence on longer-term respiratory support needs remains unknown.

OBJECTIVE

To determine if respiratory culture growth of pathogenic organisms is associated with ongoing need for respiratory support, decannulation, and death at 3 years posttracheostomy placement in children with BPD and tracheostomies.

METHODS

This single center, retrospective cohort study included infants and children with BPD and tracheostomies placed 2010-2018 and ≥1 respiratory culture obtained in 36 months posttracheostomy. Primary predictor was any pathogen identified on respiratory culture. Additional predictors were any Pseudomonas aeruginosa and chronic P. aeruginosa identification. Outcomes included continued use of respiratory support (e.g., oxygen, positive pressure), decannulation, and death at 3 years posttracheostomy. We used Poisson regression models to examine the relationship between respiratory organisms and outcomes, controlling for patient-level covariates and within-patient clustering.

RESULTS

Among 170 children, 59.4% had a pathogen identified, 28.8% ever had P. aeruginosa, and 3.5% had chronic P. aeruginosa. At 3 years, 33.1% of alive children required ongoing respiratory support and 24.8% achieved decannulation; 18.9% were deceased. In adjusted analysis, any pathogen and P. aeruginosa were not associated with ongoing respiratory support or mortality. However, P. aeruginosa was associated with decreased decannulation probability (adjusted risk ratio 0.48, 95% CI 0.23-0.98). Chronic P. aeruginosa was associated with lower survival probability.

CONCLUSION

Our findings suggest that respiratory pathogens including P. aeruginosa may not promote long-term respiratory dysfunction, but identification of P. aeruginosa may delay decannulation.

Improved recognition of lung function decline as signal of cystic fibrosis pulmonary exacerbation: a Cystic Fibrosis Learning Network Innovation Laboratory quality improvement initiative

INTRODUCTION

Cystic fibrosis (CF) is a systemic autosomal recessive condition characterised by progressive lung disease. CF pulmonary exacerbations (PEx) are episodes of worsening respiratory status, and frequent PEx are a risk factor for accelerated lung function decline, yet many people with CF (PwCF) go untreated at the time of decline. The goal of this quality improvement (QI) initiative was to improve recognition, treatment and follow-up of PEx in PwCF.

METHODS

Using the Model for Improvement, the Cystic Fibrosis Learning Network (CFLN) initiated a QI innovation laboratory (iLab) with a global aim to decrease the rate of lung function decline in PwCF. The iLab standardised definitions for signals of PEx using a threshold for decline in forced expiratory volume in one second (FEV1) and/or changes in symptoms. The FEV1 decline signal was termed FIES (FEV1-indicated exacerbation signal). Processes for screening and recognition of FIES and/or symptom changes, a treatment algorithm and follow-up in the presence of a signal were tested concurrently in multiple settings.

SPECIFIC AIMS

The specific aim is to increase the per cent of PwCF assessed for a PEx signal at ambulatory encounters and to increase the per cent of recommendations to follow-up within 6 weeks for PwCF experiencing a PEx signal.

RESULTS

FIES recognition increased from 18.6% to 73.4% across all teams during the iLab, and every team showed an improvement. Of PwCF assessed, 15.8% experienced an FIES event (>10% decline in FEV1 per cent predicted (FEV1pp)). Follow-up within 6 weeks was recommended for an average of 70.5% of those assessed for FIES and had an FEV1pp decline greater than 5%.

CONCLUSION

The CFLN iLab successfully defined and implemented a process to recognise and follow-up PEx signals. This process has the potential to be spread to the larger CF community. Further studies are needed to assess the impact of these processes on PwCF outcomes.

Integrating airway microbiome and blood proteomics data to identify multi-omic networks associated with response to pulmonary infection

Host response to airway infections can vary widely. Cystic fibrosis (CF) pulmonary exacerbations provide an opportunity to better understand the interplay between respiratory microbes and the host. This study aimed to investigate the observed heterogeneity in airway infection recovery by analyzing microbiome and host response (i.e., blood proteome) data collected during the onset of 33 pulmonary infection events. We used sparse multiple canonical correlation network (SmCCNet) analysis to integrate these two types of -omics data along with a clinical measure of recovery. Four microbe-protein SmCCNet subnetworks at infection onset were identified that strongly correlate with recovery. Our findings support existing knowledge regarding CF airway infections. Additionally, we discovered novel microbe-protein subnetworks that are associated with recovery and merit further investigation.

Health inequities in the modulator era

PURPOSE OF REVIEW

To discuss the existing health inequities in people with cystic fibrosis (CF) and how the recent development of cystic fibrosis transmembrane regulator (CFTR) modulators may impact these inequities.

RECENT FINDINGS

People with CF (pwCF) from low socioeconomic status (SES) have more pulmonary exacerbations, worse nutritional status, lower pulmonary function, and an increased mortality rate with less access to lung transplantation. pwCF who identify as racial and ethnic minorities have earlier mortality, lower lung function, are less likely to be detected on newborn screening resulting in a delayed diagnosis, are underrepresented in clinic trials, and less likely to be eligible for a CFTR modulator. Female sex is associated with more pulmonary exacerbations and earlier mortality. Sexual gender minorities are a vulnerable population with worse health outcomes, and more research is needed in CF. CFTR modulators are inaccessible to low to middle-income countries due to significant cost burden.

SUMMARY

People with CF from low SES, racial and ethnic minorities, female sex, and sexual gender minorities face health inequities. CFTR modulator use will further widen existing health inequities given the unequal access to modulators based on nonqualifying genetics and exorbitant cost restricting use both on an individual and global level.

Treatment response to pulmonary exacerbation in primary ciliary dyskinesia

INTRODUCTION

Pulmonary exacerbation (Pex) are common in pediatric primary ciliary dyskinesia (PCD), however changes in forced expiratory volume in 1 s precent predicted (FEV1pp) during Pex are not well described.

AIM

To assess the evolution of FEV1pp during Pex and to define factors associated with failure to return to baseline lung function.

METHOD

This was a retrospective study of patients with PCD between 2010 and 2022. Pex were defined as the presence of increased respiratory symptoms treated with intravenous (IV) antibiotics. The main outcomes were the changes in FEV1 during therapy and the proportion of patients (responders) achieving ≥90% of baseline FEV1pp values at the end of admission.

RESULTS

The study included 52 Pex events in 28 children with PCD. The rate of responders was 32/41 (78%) at the end of admission. Nonresponse was associated with lower median body mass index (BMI) Z-score (-2.4 vs. -0.4, p < .01) and with a history of IV treated Pex in the previous year (p = .06). For the 22 Pex with available FEV1pp measurements at mid admission, the median relative and absolute improvement from admission to Day 7 was 9.1% and 6.2%, respectively (p- .001), and from Days 7 to 14 was 4.4% and 2.8%, respectively (p = .08).

CONCLUSION

In children with PCD treated with IV antibiotics, the majority of lung function recovery happens during the first week of IV therapy. Lower BMI was associated with nonresponse to therapy.

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.

Disparities and therapeutic advances in cystic fibrosis

Cystic fibrosis (CF) has seen a multitude of therapeutic advances targeting its downstream effects. This has led to a steady increase in survival over the past few decades. The recent development of disease-modifying drugs targeting the underlying CFTR mutation has revolutionized treatment for CF. Despite these advances, individuals with CF who are racial and ethnic minorities, from low socioeconomic status, or female sex have worse clinical outcomes. The inequitable access to CFTR modulators from cost and/or genetic eligibility has the potential to further worsen the existing health disparities seen within the CF community.

Evaluation of clinically relevant changes in the lung clearance index in children with cystic fibrosis and healthy controls

BACKGROUND

The limits of reproducibility of the lung clearance index (LCI) are higher in children with cystic fibrosis (CF) compared with healthy children, and it is currently unclear what defines a clinically meaningful change.

METHODS

In a prospective multisite observational study of children with CF and healthy controls (HCs), we measured LCI, FEV₁% predicted and symptom scores at quarterly visits over 2 years. Two reviewers performed a detailed review of visits to evaluate the frequency that between visit LCI changes outside ±10%, ±15%, ±20% represented a clinically relevant signal. In the setting of acute respiratory symptoms, we used a generalised estimating equation model, with a logit link function to determine the ability of LCI worsening at different thresholds to predict failure of lung function recovery at follow-up.

RESULTS

Clinically relevant LCI changes outside ±10%, ±15% and ±20% were observed at 25.7%, 15.0% and 8.3% of CF visits (n=744), respectively. The proportions of LCI changes categorised as noise, reflecting biological variability, were comparable between CF and HC at the 10% (CF 9.9% vs HC 13.0%), 15% (CF 4.3% vs HC 3.1%) and 20% (CF 2.4% vs HC 1.0%) thresholds. Compared with symptomatic CF visits without a worsening in LCI, events with ≥10% LCI increase were more likely to fail to recover baseline LCI at follow-up.

CONCLUSION

The limits of reproducibility of the LCI in healthy children can be used to detect clinically relevant changes and thus inform clinical care in children with CF.

Anti-Pseudomonas aeruginosa Vaccines and Therapies: An Assessment of Clinical Trials

Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen that causes high morbidity and mortality in cystic fibrosis (CF) and immunocompromised patients, including patients with ventilator-associated pneumonia (VAP), severely burned patients, and patients with surgical wounds. Due to the intrinsic and extrinsic antibiotic resistance mechanisms, the ability to produce several cell-associated and extracellular virulence factors, and the capacity to adapt to several environmental conditions, eradicating P. aeruginosa within infected patients is difficult. Pseudomonas aeruginosa is one of the six multi-drug-resistant pathogens (ESKAPE) considered by the World Health Organization (WHO) as an entire group for which the development of novel antibiotics is urgently needed. In the United States (US) and within the last several years, P. aeruginosa caused 27% of deaths and approximately USD 767 million annually in health-care costs. Several P. aeruginosa therapies, including new antimicrobial agents, derivatives of existing antibiotics, novel antimicrobial agents such as bacteriophages and their chelators, potential vaccines targeting specific virulence factors, and immunotherapies have been developed. Within the last 2-3 decades, the efficacy of these different treatments was tested in clinical and preclinical trials. Despite these trials, no P. aeruginosa treatment is currently approved or available. In this review, we examined several of these clinicals, specifically those designed to combat P. aeruginosa infections in CF patients, patients with P. aeruginosa VAP, and P. aeruginosa-infected burn patients.

Cystic Fibrosis: Highly Effective Targeted Therapeutics and the Impact on Sex and Racial Disparities

People with Cystic Fibrosis (CF) are living longer and healthier lives due in part to new therapies, called Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) modulators. However, disparities in outcomes still exist, with females demonstrating a shorter life expectancy than males; this is opposed to the typical female versus male life expectancy in the general United States population. In addition, minority populations such as those of Hispanic ethnicity and African Americans are less frequently eligible for these new CFTR modulators. The mechanisms driving this difference and the relative contribution of CFTR to the etiology are not yet elucidated.

Evaluating FEV1 decline in diagnosis and management of pulmonary exacerbations in children with cystic fibrosis

RATIONALE

Forced expiratory volume in 1 s (FEV1) decline (ΔFEV1) is associated with pulmonary exacerbation (PEx) diagnosis in cystic fibrosis (CF). Spirometry may not be available during telehealth visits and could impair clinician ability to diagnose PEx. This study aims to (1) identify the associations between degrees of ΔFEV1 (decrease of <5% predicted vs. 5%-9% predicted vs. ≥10% predicted from baseline), clinical symptoms, and clinician-diagnosed PEx and (2) evaluate the correlation between respiratory symptoms, ΔFEV1, and antibiotic treatment.

METHODS

Retrospective, descriptive study of PEx diagnosis and management in 628 outpatient clinical encounters with spirometry in 178 patients with CF ages 6-17 years at Riley Hospital for Children during 2019. Odds ratios (OR) of symptoms associated with clinician-defined PEx diagnosis and antibiotic management stratified by ΔFEV1 decline were determined.

RESULTS

Clinician-diagnosed PEx occurred at 199 (31.7%) visits; increased cough (77.4%) and sputum/wet cough (57.8%) were the most frequently reported symptoms. Compared to no ΔFEV1, the odds of a clinician-diagnosed PEx were increased when ΔFEV1_5%-9% and ΔFEV1_≥10% was present with increased cough (OR 1.56, 95% confidence interval [CI] 1.25-1.94 and OR 1.82, 95% CI 1.52-2.19, respectively), increased sputum (OR 1.59, 95% CI 1.20-2.12 and OR 1.78, 95% CI 1.37-2.32, respectively), and increased cough and sputum together (OR 1.51, 95% CI 1.08-2.13 and OR 1.68, 95% CI 1.22-2.31, respectively).

CONCLUSIONS

ΔFEV1 is associated with increased likelihood that cough and sputum are diagnosed as a PEx. Spirometry is essential for PEx diagnosis and treatment and is a necessary component of all clinical encounters.

Preliminary method for profiling volatile organic compounds in breath that correlate with pulmonary function and other clinical traits of subjects diagnosed with cystic fibrosis: a pilot study

Cystic fibrosis (CF) is characterized by chronic respiratory infections which progressively decrease lung function over time. Affected individuals experience episodes of intensified respiratory symptoms called pulmonary exacerbations (PEx) which accelerate pulmonary function decline and decrease survival. There is no standard classification for PEx, which results in treatments that are heterogeneous. Improving PEx classification and management is a significant priority for people with CF. Previous studies have shown volatile organic compounds (VOCs) in exhaled breath can be used as biomarkers because they are products of metabolic pathways dysregulated by different diseases. To provide insights on PEx classification and other clinical factors, exhaled breath was collected from subjects with CF, with some experiencing PEx and others at baseline. Exhaled breath was collected in Tedlar bags during tidal breathing for VOC analysis by solid phase microextraction coupled to gas chromatography-mass spectrometry. Statistical significance testing between quantitative and categorical clinical variables displayed percent-predicted forced expiratory volume in one second (FEV1pp) was decreased in subjects experiencing PEx. VOCs correlating with other clinical variables (body mass index, age, use of highly effective modulator therapies, and need for antibiotics) were also explored. VOCs correlating to potential confounding variables were removed and analyzed by regression for correlations with FEV1pp measurements. The VOC with the highest correlation with FEV1pp (3,7-dimethyldecane) also gave the lowest p-value when comparing subjects at baseline and during PEx. Receiver operator characteristic curves showed 3,7-dimethyldecane had a higher ability to classify PEx (area under the curve (AUC) = 0.91) relative to FEV1pp values at collection (AUC = 0.83). However, normalized ΔFEV1pp values had the highest capability to distinguish PEx (AUC = 0.93). These results show that exhaled VOCs may be a source of biomarkers for various clinical traits of CF, including PEx, that should be explored in larger sample cohorts and validation studies.

Static mucus impairs bacterial clearance and allows chronic infection with Pseudomonas aeruginosa in the cystic fibrosis rat

Cystic fibrosis (CF) airway disease is characterised by chronic Pseudomonas aeruginosa infection. Successful eradication strategies have been hampered by a poor understanding of the mechanisms underlying conversion to chronicity. The CFTR-knockout (KO) rat harbors a progressive defect in mucociliary transport and viscosity. KO rats were infected before and after the appearance of the mucus defect, using a clinical, mucoid-isolate of P. aeruginosa embedded in agarose beads. Young KO rats that were exposed to bacteria before the development of mucociliary transport defects resolved the infection and subsequent tissue damage. However, older KO rats that were infected in the presence of hyperviscous and static mucus were unable to eradicate bacteria, but instead had bacterial persistence through 28 days post-infection that was accompanied by airway mucus occlusion and lingering inflammation. Normal rats responded to infection with increased mucociliary transport to supernormal rates, which reduced the severity of a second bacterial exposure. We therefore conclude that the aberrant mucus present in the CF airway permits persistence of P. aeruginosa in the lung.

Health care costs related to home spirometry in the eICE randomized trial

BACKGROUND

Home spirometry with regular symptom assessment is one strategy to track lung health to intervene early in episodes of pulmonary exacerbations (PE). In a multi-center randomized controlled trial home spirometry and symptom tracking demonstrated no significant differences regarding the primary clinical endpoint, FEV₁, compared to usual care, but did identify differences in healthcare utilization. We used data from the Early Intervention in Cystic Fibrosis Exacerbation (eICE) study to evaluate whether home monitoring of PE is a cost-minimizing intervention in the context of this randomized trial.

METHODS

We reviewed healthcare resource utilization of all 267 eICE participants, including outpatient visits, antibiotics and hospitalizations. Prices were identified in the IBM/Watson MarketScan^Ⓡ Commercial Claims and Encounters Databases and averaged over the 2014-2017 period. Using total healthcare utilization costs, we generated summary statistics by intervention and protocol arm (total cost, mean cost, standard deviation). We performed Welch Two Sample t-tests to determine if total costs and cost by type of utilization differed significantly between groups.

RESULTS

Outpatient visit costs were significantly higher by 13% in the Early Intervention (EI) than in the usual care (UC) arm ($3,345 vs. $2,966). We found no significant differences in outpatient antibiotic, hospitalization, or total health care costs between the arms.

CONCLUSIONS

Within the context of the eICE trial, outpatient visits were significantly higher in those with experimental home spirometry care, but that did not translate into statistically significant differences of overall health care costs between the two arms.

Duration of intravenous antibiotic treatment for acute exacerbations of cystic fibrosis: A systematic review: Duration of treatment for acute exacerbations of cystic fibrosis

BACKGROUND

Acute exacerbations of Cystic Fibrosis (AECF) are associated with significant morbidity. Recommendations are to treat for 2-3 weeks despite limited data. Spirometry is a measure of clinical response yet appears to plateau at 7-10 days. While durations <9 days have been associated with poorer outcomes, a duration of 10 days may be as effective as 14 days, potentially conferring advantages in terms of cost and adverse events. A 2019 Cochrane review by Abbott et al. did not identify any randomised controlled trials (RCT) comparing durations of treatment. Utilising data from non-randomised studies (NRS), we report a systematic review of intravenous antibiotic treatment, exploring changes in FEV₁ (Forced Expiratory Volume in 1 second), CRP (C-reactive protein) and peripheral WBC (white blood cell) count in studies with different treatment durations.

STUDY DESIGN AND METHODS

Systematic review of published literature following a search of MEDLINE, Embase, CINAHL and the Cochrane Clinical Trials register. Guidelines from the Preferred Reporting items for Systematic reviews and Meta-Analysis (PRISMA) and reporting Meta-analysis of Observational studies (MOOSE) statement were followed.

RESULTS

No randomised controlled trials were identified that specifically examined duration of treatment during AECF. This study included all relevant RCTs and also NRS, grouping according to study characteristics, such as length of treatment, location, year, and also characteristics of the patient population. 52 studies, comprising 79 subgroups, and 1,597 patients, were identified. Mean change (95%CI) in ppFEV₁ was 10.13 (9.21-11.05). There was no significant difference in change in ppFEV₁ for studies treating for 10-12 days; 8.85 (7.47-10.23), vs 13-15 days; 10.68 (9.53-11.82). Similar changes in CRP and WBC were seen irrespective of treatment duration.

CONCLUSION

This systematic review provides evidence that shorter durations of treatment may be associated with similar changes in FEV₁, CRP and WBC compared with longer durations.

Lung Clearance Index to Track Acute Respiratory Events in School-Age Children with Cystic Fibrosis

Rationale: The lung clearance index (LCI) is responsive to acute respiratory events in preschool children with cystic fibrosis (CF), but its utility to identify and manage these events in school-age children with CF is not well defined.Objectives: To describe changes in LCI with acute respiratory events in school-age children with CF.Methods: In a multisite prospective observational study, the LCI and FEV₁ were measured quarterly and during acute respiratory events. Linear regression was used to compare relative changes in LCI and FEV₁% predicted at acute respiratory events. Logistic regression was used to compare the odds of a significant worsening in LCI and FEV₁% predicted at acute respiratory events. Generalized estimating equation models were used to account for repeated events in the same subject.Measurements and Main Results: A total of 98 children with CF were followed for 2 years. There were 265 acute respiratory events. Relative to a stable baseline measure, LCI (+8.9%; 95% confidence interval, 6.5 to 11.3) and FEV₁% predicted (-6.6%; 95% confidence interval, -8.3 to -5.0) worsened with acute respiratory events. A greater proportion of events had a worsening in LCI compared with a decline in FEV₁% predicted (41.7% vs. 30.0%; P = 0.012); 53.9% of events were associated with worsening in LCI or FEV₁. Neither LCI nor FEV₁ recovered to baseline values at the next follow-up visit.Conclusions: In school-age children with CF, the LCI is a sensitive measure to assess lung function worsening with acute respiratory events and incomplete recovery at follow-up. In combination, the LCI and FEV₁ capture a higher proportion of events with functional impairment.

SPLUNC1: a novel marker of cystic fibrosis exacerbations

Acute pulmonary Exacerbations (AE) are episodes of clinical worsening in cystic fibrosis (CF), often precipitated by infection. Timely detection is critical to minimise morbidity and lung function declines associated with acute inflammation during AE. Based on our previous observations that airway protein Short Palate Lung Nasal epithelium Clone 1 (SPLUNC1) is regulated by inflammatory signals, we investigated the use of SPLUNC1 fluctuations to diagnose and predict AE in CF.We enrolled CF participants from two independent cohorts to measure AE markers of inflammation in sputum and recorded clinical outcomes for a 1-year follow-up period.SPLUNC1 levels were high in healthy controls (n=9, 10.7 μg mL^-1), and significantly decreased in CF participants without AE (n=30, 5.7 μg mL^-1, p=0.016). SPLUNC1 levels were 71.9% lower during AE (n=14, 1.6 μg mL^-1, p=0.0034) regardless of age, sex, CF-causing mutation, or microbiology findings. Cytokines Il-1β and TNFα were also increased in AE, whereas lung function did not consistently decrease. Stable CF participants with lower SPLUNC1 levels were much more likely to have an AE at 60 days (HR: 11.49, Standard Error: 0.83, p=0.0033). Low-SPLUNC1 stable participants remained at higher AE risk even one year after sputum collection (HR: 3.21, Standard Error: 0.47, p=0.0125). SPLUNC1 was downregulated by inflammatory cytokines and proteases increased in sputum during AE.In acute CF care, low SPLUNC1 levels could support a decision to increase airway clearance or to initiate pharmacological interventions. In asymptomatic, stable patients, low SPLUNC1 levels could inform changes in clinical management to improve long-term disease control and clinical outcomes in CF.

Evaluation of rescue oral glucocorticoid therapy during inpatient cystic fibrosis exacerbations

An acute pulmonary exacerbation (APE) in cystic fibrosis (CF) is characterized by increased pulmonary symptoms attributed to bacterial colonization, neutrophil recruitment, and inflammation. Antimicrobials, airway clearance, and nutrition are the mainstay of therapy. However, when patients fail to improve, corticosteroids have been added to therapy. We retrospectively examined the use of rescue steroids in a children's hospital from 2013 to 2017 during CF APE treatment following at least 1 week of inpatient therapy without expected clinical improvement. In total, 106 encounters of 53 unique patients, aged 6-20 years, who had FEV1 percent predicted (FEV1pp) data at baseline, admission, midpoint, and discharge, and had admission duration of at least 12 days were studied. Encounters treated with steroids had less improvement at midpoint percent change from admission in FEV1pp (4.9 ± 11.3) than nonsteroid group change in FEV1pp (20.1 ± 24.6; p < .001). Failure to improve as expected was the rationale for steroid use. At discharge, there was no difference in mean FEV1pp (p = .76). Delays in steroid therapy by waiting until the end of the second week increased the total length of stay (LOS). Propensity matching, comparing outcomes in patients without midpoint improvement in FEV1pp, was also evaluated. There was no difference in admission or discharge FEV1pp between groups. Equally, no difference in FEV1pp at follow-up visit or in time until the next APE was detected. Secondary analysis for associations including gender, genotype, fungal colonization, or inhaled antimicrobials was nonsignificant. These data suggest rescue use of corticosteroids during APE does not predictably impact important outcome measures during CF APE treatment.

The role of inflammation in cystic fibrosis pulmonary exacerbations

INTRODUCTION

Cystic Fibrosis pulmonary exacerbations are critical events in the lives of people with CF that have deleterious effects on lung function, quality of life, and life expectancy. There are significant unmet needs in the management of exacerbations. We review here the associated inflammatory changes that underlie these events and are of interest for the development of biomarkers of exacerbation.

AREAS COVERED

Inflammatory responses in CF are abnormal and contribute to a sustained proinflammatory lung microenvironment, abundant in proinflammatory mediators and deficient in counter-regulatory mediators that terminate and resolve inflammation. There is increasing interest in these inflammatory pathways to discover novel biomarkers for pulmonary exacerbation management. In this review, we explore the inflammatory changes occurring during intravenous antibiotic therapy for exacerbation and how they may be applied as biomarkers to guide exacerbation therapy. A literature search was conducted using the PubMed database in February 2020.

EXPERT OPINION

Heterogeneity in inflammatory responses to treatment of a pulmonary exacerbation, a disease process with complex pathophysiology, limits the clinical utility of individual biomarkers. Biomarker panels may be a more successful strategy to capture informative changes within the CF population to improve pulmonary exacerbation management and outcomes.

Azithromycin is the answer in paediatric respiratory medicine, but what was the question?

The first clinical indication of non-antibiotic benefits of macrolides was in the Far East, in adults with diffuse panbronchiolitis. This condition is characterised by chronic airway infection, often with Pseudomonas aeruginosa, airway inflammation, bronchiectasis and a high mortality. Low dose erythromycin, and subsequently other macrolides, led in many cases to complete remission of the condition, and abrogated the neutrophilic airway inflammation characteristic of the disease. This dramatic finding sparked a flurry of interest in the many hundreds of macrolides in nature, especially their anti-inflammatory and immunomodulatory effects. The biggest subsequent trials of azithromycin were in cystic fibrosis, which has obvious similarities to diffuse panbronchiolitis. There were unquestionable improvements in lung function and pulmonary exacerbations, but compared to diffuse panbronchiolitis, the results were disappointing. Case reports, case series and some randomised controlled trials followed in other conditions. Three trials of azithromycin in preschool wheeze gave contradictory results; a trial in pauci-inflammatory adult asthma, and a trial in non-cystic fibrosis bronchiectasis both showed a significant reduction in exacerbations, but none matched the dramatic results in diffuse panbronchiolitis. There is clearly a huge risk of antibacterial resistance if macrolides are used widely and uncritically in the community. In summary, Azithromycin is not the answer to anything in paediatric respiratory medicine; the paediatric respiratory community needs to refocus on the dramatic benefits of macrolides in diffuse panbronchiolitis, use modern - omics technologies to determine the endotypes of inflammatory diseases and discover in nature or synthesise designer macrolides to replicate the diffuse panbronchiolitis results. We must now find out how to do better!

Lung function changes before and after pulmonary exacerbation antimicrobial treatment in cystic fibrosis

BACKGROUND

In cystic fibrosis, observation of a lung function drop (as percent predicted forced expiratory volume in 1 s [FEV₁ ]; ppFEV₁ ) frequently precedes pulmonary exacerbation (PEx) diagnosis. Recovery of ppFEV₁ to a previous "baseline" is commonly used to assess antimicrobial treatment response. However, not all diagnosed PEx are associated with a ppFEV₁ drop, and it is unclear whether these are a different type of PEx from those associated with a ppFEV₁ drop.

METHODS

We analyzed pre- and posttreatment ppFEV₁ for PEx recorded in the Epidemiologic Study of Cystic Fibrosis from 2003 through 2005. Baseline, pretreatment, and follow-up ppFEV₁ were the best recorded within 12-months pre-PEx, the lowest recorded -30 to +3 days of treatment, and the best recorded during 6-month follow-up, respectively. Logistic regression models for return of ppFEV₁ to baseline during follow-up were developed separately for PEx with ≥10%, <10%, and no ppFEV₁ drop before treatment.

RESULTS

Of 15 147 PEx, 10 166 (67.1%), 3479 (23.0%), and 1502 (9.9%) presented with a ≥10%, <10%, or no ppFEV₁ drop at diagnosis, respectively. 19.5%, 35.2%, and 65.6% of PEx, respectively, had follow-up ppFEV₁ equal to or exceeding baseline; overall 27.7% of all PEx treatments resulted in complete recovery of baseline ppFEV₁ . Significant predictors of ppFEV₁ recovery at follow-up were younger patient age, absence of Aspergillus, lower baseline ppFEV₁ , fewer visits during the baseline, lower frequency of prior-year PEx, shorter elapsed time from baseline measure to treatment, smaller relative ppFEV₁ drop before treatment, and non intravenous (ie, oral or inhaled antibiotic) treatment. PEx with ≥10%, <10%, and no ppFEV₁ drop before treatment had only modest differences in covariate odds ratios associated with complete ppFEV₁ recovery.

CONCLUSIONS

Among the 10% of PEx presenting with no apparent ppFEV₁ drop, more than one-third resulted in a decreased ppFEV₁ during follow-up. Risk factors for this outcome were the same as those associated with lack of ppFEV₁ recovery among PEx with pretreatment ppFEV₁ drops. These results suggest that inherent FEV₁ variability, baseline and follow-up sampling methodologies, ppFEV₁ regression to the mean, and underlying lung disease progression complicate this approach for assessing effects of PEx and treatment response.

Vitamin D status correlates with the markers of cystic fibrosis-related pulmonary disease

BACKGROUND

The prevalence of Vitamin D deficiency remains high in cystic fibrosis despite daily supplementation. Vitamin D as an immunomodulator has been related to lower respiratory tract infections in children. The present study was undertaken to examine the association between vitamin D status and markers of cystic fibrosis-related pulmonary disease including exacerbations, bacterial colonization and pulmonary function.

METHODS

The study includes review of records of 51 cystic fibrosis patients. Baseline patient variables and serum vitamin D levels were recorded. Based on vitamin D levels study patients were divided into three groups: vitamin-D sufficient (≥20 ng/mL), vitamin-D insufficient (12 to 20 ng/mL), and vitamin D-deficient (≤12 ng/ml).

RESULTS

The proportion of children with deficient, insufficient and sufficient vitamin D levels were 47.1%, 15.7%, and 37.2%, respectively. Female sex, bacterial colonization and a greater number of exacerbations were associated with highest odds of developing vitamin D deficiency in patients with CF with 1.77 (0.22-4.61) (p = 0.002), 2.9(0.57-14.82) (p = 0.011), and 5.12 (1.28-20.50) (p = 0.021) respectively. The comparison of vitamin-D levels taken during exacerbations, colonization and during routine follow-up were significant [16.04 (7.42-27.91), 24.3 (15.5-32.4) and 48.54 (18.37-78.7) ng/ml, p < 0.001]. The FEV1 was determined in 24 patients; the comparison was significant between vitamin D-deficient and -sufficient groups [0.75 (0.717-0.777) vs. 0.82 (0.74-0.92) p < 0.05].

CONCLUSION

We concluded that vitamin D deficiency was highly prevalent in children with CF, despite daily supplementation of the vitamin in diet. Further, vitamin D deficiency was associated with a higher rate of pulmonary exacerbations and higher incidence of pulmonary bacterial colonization. In addition, in younger patients, low vitamin D levels were associated with reduced pulmonary function.

Application of multiple event analysis as an alternative approach to studying pulmonary exacerbations as an outcome measure

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.

Measuring recovery in health-related quality of life during and after pulmonary exacerbations in patients with cystic fibrosis

BACKGROUND

We explored the time-dependent impact of pulmonary exacerbations (PEx) on health-related quality of life (HRQoL) using Cystic Fibrosis Questionnaire-Revised (CFQ-R) data from 2 large cystic fibrosis (CF) trials.

METHODS

This exploratory post-hoc analysis evaluated the impact of PEx on CFQ-R domains of functioning in 80 patients with CF (homozygous for F508del-CFTR), aged ≥14 years randomized to placebo in the TRAFFIC and TRANSPORT trials who experienced 1 PEx.

RESULTS

Scores on the CFQ-R were significantly lower within 1 week of PEx start in 8 out of 12 domains (Respiratory Symptoms, Physical Functioning, Emotional Functioning, Health Perceptions, Role Functioning, Social Functioning, Eating, and Vitality). Patients whose PEx was treated with hospitalization or intravenous antibiotics had greater reductions in some domains of HRQoL compared with those treated with oral antibiotics. In the immediate weeks post-PEx, improvement was seen on Emotional Functioning, Respiratory Symptoms, and Health Perceptions, while further decline was seen for Eating, Physical Functioning, Role Functioning, Vitality, and Weight. For some measures (Physical Functioning, Vitality), full recovery to pre-PEx levels took several weeks.

CONCLUSIONS

Pulmonary exacerbations have significant effects on multiple domains of HRQoL, and recovery across multiple domains post-PEx can take several weeks. These findings provide insight into the impact of PEx on patient HRQoL and recovery post-PEx.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifiers, NCT01807923 and NCT01807949.

Reevaluating approaches to cystic fibrosis pulmonary exacerbations

Cystic Fibrosis (CF) lung disease is characterized by intermittent acute episodes of worsening signs, symptoms, and pulmonary function; these so-called pulmonary exacerbations (PEx) appear to be important drivers of long-term declines in lung function, quality of life, and life expectancy. Surveillance for development of PEx and their treatment is a fundamental component of chronic CF management, and the merits of novel CF therapies are often judged based on their ability to reduce the frequency of PEx. Given the central role that they play, it is surprising how poorly PEx are understood, how thin is the evidence base for their treatment and how often they are left unrecognized and untreated in clinical practice. This paper reviews what is known and what is unknown regarding the nature of PEx, and discusses the impact of missed recognition and treatment of these episodes as well as the apparent variation in practice across CF care centers. The arguments supporting a liberal, highly sensitive approach to the diagnosis of PEx are presented, as well as recommendation for how care programs can achieve consistency in their early recognition and treatment. A stepwise approach to personalized treatment supported by close follow-up to ensure the successful resolution of all signs and symptoms will lead to the stabilization of patients' lung function and quality of life. Recommendations are made regarding important priorities for research into evidence-based approaches to improving the care of PEx.

Lumacaftor/Ivacaftor reduces pulmonary exacerbations in patients irrespective of initial changes in FEV1

BACKGROUND

Improved lung function and fewer pulmonary exacerbations (PEx) were observed with lumacaftor/ivacaftor (LUM/IVA) in patients with cystic fibrosis homozygous for F508del. It is unknown whether PEx reduction extends to patients without early lung function improvement.

METHODS

Post hoc analyses of pooled phase 3 data (NCT01807923, NCT01807949) categorized LUM/IVA-treated patients by percent predicted forced expiratory volume in 1 s (ppFEV₁) change from baseline to day 15 into threshold categories (absolute change ≤0 vs >0; relative change <5% vs ≥5%) and compared PEx rates vs placebo.

RESULTS

LUM (400 mg q12h)/IVA (250 mg q12h)-treated patients (n = 369) experienced significantly fewer PEx vs placebo, regardless of threshold category. With LUM/IVA, PEx rate per patient per year was 0.60 for those with absolute change in ppFEV₁ > 0 and 0.85 for those with absolute change ≤0 (respective rate ratios vs placebo [95% CI]: 0.53 [0.40-0.69; P < .0001], 0.74 [0.55-0.99; P = .04]).

CONCLUSIONS

LUM/IVA significantly reduced PEx, even in patients without early lung function improvement.

Unmet needs in cystic fibrosis: the next steps in improving outcomes

INTRODUCTION

Cystic fibrosis (CF) outcomes and survival have improved over the last century primarily due to advancements in antibiotics, nutritional, and pulmonary therapies. Reviewed here are the significant unmet needs that exist for individuals with CF. Areas covered: With the recent development of medications that address the underlying defect in the CF protein, there is hope that there will be continued improvement in CF outcomes. However, there remains a need to prevent or stop progression of CF-related complications, as the CF protein is important to several body systems. As end stage lung disease is the primary cause of mortality in CF, a need exists for advancements in pulmonary therapies to reduce time burden, identification of best practices for the treatment of pulmonary exacerbations, further development of anti-infective and anti-inflammatory therapies, and appropriately timed referral for lung transplantation at end-stage lung disease. Extra-pulmonary complications are increasingly recognized and better understanding of such problems as CF related liver disease is needed. Expert commentary: While CFTR modulators are available for the majority of CF patients, there remains a need for effective therapies to address infection, inflammation, irreversible lung disease, and extrapulmonary complications of CF.

Characteristics and outcomes of oral antibiotic treated pulmonary exacerbations in children with cystic fibrosis

Background

Pulmonary exacerbations (PEx) in children with cystic fibrosis (CF) are frequently treated in the outpatient setting with oral antibiotics. However, little is known about the characteristics of PEx managed on an outpatient basis and the effectiveness of oral antibiotic therapy. We sought to prospectively evaluate clinical and laboratory changes associated with oral antibiotic treatment for PEx.

Methods

Children with CF between 8 and 18 years of age prescribed two weeks of oral antibiotics for a PEx were eligible to enroll. The study consisted of a visit within 48 h of starting antibiotics and a second visit within one week of antibiotic completion. Twenty-eight participants were evaluated by exacerbation score, quality of life measurements, lung function, sputum microbiology and inflammation.

Results

Oral antibiotic treatment was associated with a significant improvement in exacerbation score and quality of life measured by the CF Questionnaire-Revised (CFQ-R) respiratory domain. Following treatment, forced expiratory volume in 1 s (FEV₁) % predicted increased [median (range)] 9% (−8%, 31%), and 22 (81%) subjects returned to 90% or higher of baseline FEV₁. Bacterial density of the primary organism identified on sputum culture decreased significantly with a median (range) decrease of 0.8 log₁₀ cfu/mL (−8 log₁₀, 2 log_10, p = 0.03). Sputum neutrophil elastase [−37 μg/mL (−464, 272), p = 0.02] and IL-1β [−2.8 × 10³μg/mL (−6.9 × 10⁴, 3.3 × 10⁴), p = 0.03] decreased significantly following treatment in this cohort.

Conclusions

Treatment of PEx with oral antibiotics was associated with measurable improvements in patient reported outcomes, lung function, bacterial density and sputum inflammatory markers.

Constrictive Bronchiolitis in Cystic Fibrosis Adolescents with Refractory Pulmonary Decline

RATIONALE

Refractory lung function decline in association with recurrent pulmonary exacerbations is a common, yet poorly explained finding in cystic fibrosis (CF). To investigate the histopathologic mechanisms of pulmonary deterioration during adolescence and early adulthood, we reviewed clinically-indicated lung biopsy specimens obtained during a period of persistent decline.

OBJECTIVES

To determine if peribronchiolar remodeling is prominent in lung biopsy specimens obtained in adolescents with CF refractory to conventional therapy.

METHODS

Six adolescents with CF (mean age, 16.2 y; mean FEV₁, 52% predicted at biopsy) with significant pulmonary deterioration over 12-24 months (mean FEV₁ decline of 14% predicted/year) despite aggressive intervention underwent computed tomography imaging and ultimately lung biopsy to aid clinical management. In addition to routine clinical evaluation, histopathologic investigation included staining for transforming growth factor-β (TGF-β, a genetic modifier of CF lung disease), collagen deposition (a marker of fibrosis), elastin (to evaluate for bronchiectasis), and α-smooth muscle actin (to identify myofibroblasts).

MEASUREMENTS AND MAIN RESULTS

All computed tomography scans demonstrated a mix of bronchiectasis and hyperinflation that was variable across lung regions and within patients. Lung biopsy revealed significant peribronchiolar remodeling, particularly in patients with more advanced disease, with near complete obliteration of the peribronchiolar lumen (constrictive bronchiolitis). Myofibroblast differentiation (a TGF-β-dependent process) was prominent in specimens with significant airway remodeling.

CONCLUSIONS

Constrictive bronchiolitis is widely present in the lung tissue of adolescents with CF with advanced disease and may contribute to impaired lung function that is refractory to conventional therapy (antibiotics, antiinflammatories, and mucolytics). TGF-β-dependent myofibroblast differentiation is prominent in areas of active fibrogenesis and may foster small airway remodeling in CF lung disease.

Epidemiology of CF: How registries can be used to advance our understanding of the CF population

Cystic fibrosis (CF) registries work by bringing patient data together from specialist CF centres and accumulating data on a relatively rare condition over patients' lifetimes. In this review, we examine the origin of national CF registries, the use of registries for monitoring the health of the population, the power of conducting longitudinal analysis of registry data, knowledge gleaned from changing demographics, the evolving area of international comparisons of registries, strategies for sustaining registries and CF registries of the future. Examples of research undertaken using registry data and routinely reported CF registry statistics from across the world are provided. The application, utility and challenges facing CF registries in the future are discussed.

Exercise performance and quality of life in children with cystic fibrosis and mildly impaired lung function: relation with antibiotic treatments and hospitalization

This study evaluates the impact of antibiotic treatments and hospitalization on exercise performance and health-related quality of life (QOL) in children with mild cystic fibrosis (CF) lung disease. Forty-seven children between 7 and 17 years with mild CF underwent a maximal exercise test including spiro-ergometry and filled out a QOL-questionnaire (PedsQL™). Amount of antibiotic treatments (AB) and hospitalization days in the last 3 years were reviewed. FEV1% was mildly decreased (91.7 ± 17.9 L/min, p = 0.02). Maximal oxygen consumption (VO₂max), test duration and anaerobic threshold were lower compared to a control population (VO₂max% 94 ± 15 vs 103 ± 13, p = 0.009). FEV1% correlated with AB and hospitalization episodes in the last year and 3 years before testing, VO₂max% only correlated with AB in the last 3 years. Domains of school functioning and emotional functioning were low. Children with higher VO₂max% and less AB in the last 3 years had better physical health. Physical health and school functioning were negatively correlated with hospitalization days in the last year.

CONCLUSION

Patients with mild CF lung disease have good exercise performance although still lower than the normal population. VO2max% is affected by number of antibiotic treatments over a longer period. There is an impact of hospitalization days on quality of life. What is Known: • Children with CF have lower exercise performance; there is an association between hospitalization frequency and exercise performance • Quality of life is diminished in children with CF and influenced by respiratory infections What is New: • Even patients with mild CF lung disease have lower maximal exercise performance (VO ₂ max) and a lower anaerobic threshold; VO ₂ max is lower in children who had more antibiotic treatments in the last 3 years • School and emotional functioning are diminished in children with mild CF lung disease; hospitalization is negatively correlated with school functioning and physical functioning.

Multiple reaction monitoring mass spectrometry to identify novel plasma protein biomarkers of treatment response in cystic fibrosis pulmonary exacerbations

BACKGROUND

Systemic inflammation decreases with IV antibiotics during the treatment of CF pulmonary exacerbations (PEx). We used multiple reaction monitoring mass spectrometry and immunoassays to monitor blood proteins during PEx treatment to determine if early changes could be used to predict PEx outcomes following treatment.

METHODS

Blood samples from 25 PEx (22 unique adults) were collected within 24h of admission, day 5, day 10, and at IV antibiotic completion. Ninety-two blood proteins involved in host immunity and inflammation were measured.

RESULTS

Levels of several blood proteins changed from admission to end of IV antibiotics, most increasing with treatment. Early changes (admission to day 5) in fibrinogen levels had the strongest correlation with overall improvement in CFRSD-CRISS and FEV₁% predicted by the end of treatment.

CONCLUSIONS

Several plasma proteins changed significantly with IV antibiotics. Future studies will evaluate fibrinogen as an early biomarker of PEx treatment response in CF.

Poor recovery from cystic fibrosis pulmonary exacerbations is associated with poor long-term outcomes

RATIONALE

People with CF treated with IV antibiotics for a pulmonary exacerbation (PEx) frequently fail to recover to baseline FEV₁ . The long-term impact of these events has not been studied.

OBJECTIVES

To determine if a patient's spirometric recovery after a PEx is associated with time to next PEx within 1 year, the spirometric recovery after the next PEx, and/or the number of PEx episodes in the next 3 years.

METHODS

We used data from the CF Foundation Patient Registry from 2004 to 2011. We randomly selected one PEx per patient that met inclusion/exclusion criteria. Patients were defined as Non-Responders if their best FEV₁ (in liters) recorded in the 3 months after the PEx was <90% of the best FEV₁ (in liters) in the 6 months before the PEx. We compared Responders and Non-Responders using multivariable regression models.

RESULTS

We randomly chose 13 954 PEx episodes that met inclusion/exclusion criteria. A total of 2 762 (19.8%) patients were classified as Non-Responders. Non-Responders had a shorter median time to the next PEx, 235 (95%CI 218, 252) days, versus >365 days for Responders. Thirty-four percent of Non-Responders at the initial PEx were also Non-Reponders at the next PEx, versus 20% of Responders at the initial PEx. Non-Responders had more PEx episodes over the next 3 years, 4.99 (95%CI 4.84, 5.13), than Responders, 3.46 (95%CI 3.41, 3.51).

CONCLUSIONS

Poor recovery after a PEx is associated with a shorter time to the next PEx, increased risk of poor recovery at a second PEx, and more frequent subsequent PEx treatments.

Poor recovery from a pulmonary exacerbation does not lead to accelerated FEV1 decline

BACKGROUND

Patients with CF treated for pulmonary exacerbations (PEx) may experience faster subsequent declines in FEV1. Additionally, incomplete recovery to baseline FEV1 occurs frequently following PEx treatment. Whether accelerated declines in FEV1 are preceded by poor PEx recovery has not been studied.

METHODS

Using 2004 to 2011 CF Foundation Patient Registry data, we randomly selected one PEx among patients ≥6years of age with no organ transplantations, ≥12months of data before and after the PEx, and ≥1 FEV1 recorded within the 6months before and 3months after the PEx. We defined poor PEx recovery as the best FEV1 in the 3months after the PEx <90% of the best FEV1 in the 6months before the PEx. We calculated mean (95% CI) hazard ratios (HR) of having >5% predicted/year FEV1 decline and poor PEx recovery using multi-state Markov models.

RESULTS

From 13,954 PEx, FEV1 declines of >5% predicted/year were more likely to precede poor spirometric recovery, HR 1.17 (1.08, 1.26), in Markov models adjusted for age and sex. Non-Responders were less likely to have a subsequent fast FEV1 decline, HR 0.41 (0.37, 0.46), than patients who recovered to >90% of baseline FEV1 following PEx treatment.

CONCLUSIONS

Accelerated declines in FEV1 are more likely to precede a PEx with poor recovery than to occur in the following year. Preventing or halting declines in FEV1 may also have the benefit of preventing PEx episodes.

Recovery of lung function following a pulmonary exacerbation in patients with cystic fibrosis and the G551D-CFTR mutation treated with ivacaftor

BACKGROUND

Pulmonary exacerbations (PEx) are associated with acute loss of lung function that is often not recovered after treatment. We investigated lung function recovery following PEx for ivacaftor- and placebo-treated subjects.

METHODS

Short- and long-term pulmonary function recovery data after PEx were summarized from a placebo-controlled trial in 161 cystic fibrosis patients≥12years old with the G551D-CFTR mutation (NCT00909532). Short-term recovery was measured 2 to 8weeks after treatment, and long-term recovery was determined at the end-of-study, both compared with baseline measured just prior to the PEx.

RESULTS

Fewer patients receiving ivacaftor experienced a PEx than patients receiving placebo (33.7% vs. 56.4%; P=0.004) and had a lower adjusted incidence rate of PEx (0.589 vs. 1.382; P<0.001). The proportion of PEx followed by full short-term recovery of percent predicted forced expiratory volume in 1s was similar (ivacaftor vs. placebo, 57.1% vs. 53.7), as was the proportion of patients having long-term recovery (46.4% vs. 47.7%).

CONCLUSIONS

Ivacaftor treatment reduces the frequency of PEx but does not improve on the rate of complete lung function recovery after PEx when compared with placebo.

Common clinical features of CF (respiratory disease and exocrine pancreatic insufficiency)

First described as a disease of the pancreas, cystic fibrosis is a genetically inherited progressive disease affecting multiple organ systems. Pulmonary and pancreatic involvement is common in individuals with cystic fibrosis, and the former is attributable to most of the mortality that occurs with the condition. This chapter provides an overview of a clinical approach to the pulmonary and pancreatic manifestations of cystic fibrosis.

Standardized Treatment of Pulmonary Exacerbations (STOP) study: Physician treatment practices and outcomes for individuals with cystic fibrosis with pulmonary Exacerbations

BACKGROUND

Pulmonary Exacerbations (PEx) are associated with increased morbidity and mortality in individuals with CF. PEx management practices vary widely, and optimization through interventional trials could potentially improve outcomes. The object of this analysis was to evaluate current physician treatment practices and patient outcomes for PEx.

METHODS

The Standardized Treatment of Pulmonary Exacerbations (STOP) observational study enrolled 220 participants ≥12years old admitted to the hospital for PEx at 11 U.S. CF centers. Spirometry and daily symptom scores were collected during the study. Physicians were surveyed on treatment goals and their management practices were observed. Treatment outcomes were compared to stated goals.

RESULTS

The mean (SD) duration of IV antibiotic treatment was 15.9 (6.0) days. Those individuals with more severe lung disease (<50% FEV₁) were treated nearly two days longer than those with >50% FEV₁. Physician-reported FEV₁ improvement goals were 10% (95% CI: 5%, 14%) lower for patients with 6-month baseline FEV₁ ≤50% predicted compared with those with 6-month baseline FEV₁ >50% predicted. There were clinically and statistically significant improvements in symptoms from the start of IV antibiotic treatment to the end of IV antibiotic treatment and 28days after the start of treatment. The mean absolute increase in FEV₁ from admission was 9% predicted at end of IV antibiotic treatment, and 7% predicted at day 28. Only 39% fully recovered lost lung function, and only 65% recovered at least 90% of lost lung function. Treatment was deemed successful by 84% of clinicians, although 6-month baseline FEV₁ was only recovered in 39% of PEx.

CONCLUSIONS

In this prospective observational study of PEx, treatment regimens and durations showed substantial variation. A significant proportion of patients did not reach physician's treatment goals, yet treatment was deemed successful.

Clinical utility of C-reactive protein to predict treatment response during cystic fibrosis pulmonary exacerbations

Rationale

C-reactive protein (CRP) is a systemic marker of inflammation that correlates with disease status in cystic fibrosis (CF). The clinical utility of CRP measurement to guide pulmonary exacerbation (PEx) treatment decisions remains uncertain.

Objectives

To determine whether monitoring CRP during PEx treatment can be used to predict treatment response. We hypothesized that early changes in CRP can be used to predict treatment response.

Methods

We reviewed all PEx events requiring hospitalization for intravenous (IV) antibiotics over 2 years at our institution. 83 PEx events met our eligibility criteria. CRP levels from admission to day 5 were evaluated to predict treatment non-response, using a modified version of a prior published composite definition. CRP was also evaluated to predict time until next exacerbation (TUNE).

Measurements and main results

53% of 83 PEx events were classified as treatment non-response. Paradoxically, 24% of PEx events were characterized by a ≥ 50% increase in CRP levels within the first five days of treatment. Absolute change in CRP from admission to day 5 was not associated with treatment non-response (p = 0.58). Adjusted for FEV₁% predicted, admission log₁₀ CRP was associated with treatment non-response (OR: 2.39; 95% CI: 1.14 to 5.91; p = 0.03) and shorter TUNE (HR: 1.60; 95% CI: 1.13 to 2.27; p = 0.008). The area under the receiver operating characteristics (ROC) curve of admission CRP to predict treatment non-response was 0.72 (95% CI 0.61–0.83; p<0.001). 23% of PEx events were characterized by an admission CRP of > 75 mg/L with a specificity of 90% for treatment non-response.

Conclusions

Admission CRP predicts treatment non-response and time until next exacerbation. A very elevated admission CRP (>75mg/L) is highly specific for treatment non-response and might be used to target high-risk patients for future interventional studies aimed at improving exacerbation outcomes.

'The Microbiome and the Pathophysiology of Asthma'

Asthma is a chronic respiratory disease whose prevalence is increasing in the western world. Recently research has begun to focus on the role the microbiome plays in asthma pathogenesis in the hope of further understanding this respiratory disorder. Considered sterile until recently, the lungs have revealed themselves to contain a unique microbiota. A shift towards molecular methods for the quantification and sequencing of microbial DNA has revealed that the airways harbour a unique microbiota with apparent, reproducible differences present between healthy and diseased lungs. There is a hope that in classifying the microbial load of the asthmatic airway an insight may be afforded as to the possible role pulmonary microbes may have in propagating an asthmatic airway response. This could potentially pave the way for new therapeutic strategies for the treatment of chronic lung conditions such as asthma.

Recovery of baseline lung function after pulmonary exacerbation in children with primary ciliary dyskinesia

RATIONALE

Spirometry in children with cystic fibrosis (CF) frequently fails to return to baseline after treatment for a pulmonary exacerbation. It is unclear whether the same is true for children with primary ciliary dyskinesia (PCD).

OBJECTIVES

To determine in children with PCD treated with intravenous antibiotics for a pulmonary exacerbation: (1) the proportion who recover to baseline forced expiratory volume at 1 sec (FEV₁ ) within 3 months after treatment and (2) to try to identify factors which are associated with failure to regain pre-exacerbation FEV₁ .

METHODS

Cohort study using the PCD database for children at the Royal Brompton Hospital, 2003-2013. We selected the first pulmonary exacerbation treated with intravenous antibiotics. The best FEV₁ within 3 months after treatment was compared to the best FEV₁ in the 12 months before treatment (baseline). Recovery to baseline was defined as any FEV₁ after treatment that was greater than or equal to 90% of the baseline FEV₁ .

RESULTS

32/150 children (21%) had at least one pulmonary exacerbation. 23/30 (77%) regained baseline spirometry within 3 months of treatment. There was no difference between responders and non-responders in any baseline characteristics.

CONCLUSIONS

Around 25% of children with PCD fail to recover to baseline lung function within 3 months following treatment for a pulmonary exacerbation, similar to CF. Better treatment strategies are needed, and the results also suggest that prevention of exacerbations would be a useful end-point in clinical trials. Pediatr Pulmonol. 2016;51:1362-1366. © 2016 Wiley Periodicals, Inc.

Treatment of Pulmonary Exacerbations Improves Short But Not Long-Term Growth Trajectory in Children With Cystic Fibrosis

OBJECTIVES

The present study sought to determine the long-term growth consequences after a pulmonary exacerbation in children with cystic fibrosis (CF).

METHODS

Retrospective cohort study of pediatric patients with CF with a hospital admission for a pulmonary exacerbation. Logistic regression used to determine risk factors for failure to recover baseline body mass index (BMI) percentile.

RESULTS

Of 72 patients, 43% failed to recover their baseline BMI percentile 12 months after discharge and these patients also had a lower forced expiratory volume in 1 second at follow-up. A greater decrease in weight percentile from baseline to admission was the only risk factor identified (odds ratio 0.83, P = 0.0015).

CONCLUSIONS

Greater decrease in weight percentile from baseline to admission predicts failure to recover BMI percentile 1 year after a pulmonary exacerbation. Children with CF with poor growth preceding a pulmonary exacerbation continue to be at risk for long-term nutritional failure despite treatment for pulmonary exacerbation.

Transitions in Health Care: What Can We Learn from Our Experience with Cystic Fibrosis

Numerous individuals with chronic disease age into adulthood each year, necessitating transition from a pediatric to an adult medical care team. Transition should start early in adolescence and occur gradually over years, preparing the individual for the transfer to the adult team. Cystic fibrosis (CF) has a growing population of adults, as survival over the past several decades has increased. The CF Foundation has implemented guidelines for the transition process. The transition process for individuals with CF provides an example that could be adapted into other chronic disease populations, to provide a successful and meaningful transition into adult care.

Pneumococcal vaccines for cystic fibrosis

BACKGROUND

Invasive pneumococcal disease is associated with significant mortality and many countries have introduced routine pneumococcal vaccination into their childhood immunisation programmes. Whilst pneumococcal disease in cystic fibrosis is uncommon, pneumococcal immunisation may offer some protection against pulmonary exacerbations caused by this pathogen. In the USA and UK pneumococcal vaccination is currently recommended for all children and adults with cystic fibrosis. This is an update of a previously published review.

OBJECTIVES

To assess the efficacy of pneumococcal vaccines in reducing morbidity in people with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Cystic Fibrosis Trials Register, which comprises references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. In addition, the pharmaceutical manufacturers of the polysaccharide and conjugate pneumococcal vaccines were approached.Date of the most recent search: 27 June 2016.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing pneumococcal vaccination (with either a polysaccharide or conjugate pneumococcal vaccine) with non-vaccination or placebo in children or adults with cystic fibrosis were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

No relevant trials were identified.

MAIN RESULTS

There are no trials included in this review.

AUTHORS' CONCLUSIONS

As no trials were identified we cannot draw conclusions on the efficacy of routine pneumococcal immunisation in people with cystic fibrosis in reducing their morbidity or mortality. As many countries now include pneumococcal immunisation in their routine childhood vaccination schedule it is unlikely that future randomised controlled trials will be initiated. Rigorously conducted epidemiological studies may offer the opportunity to evaluate the efficacy of pneumococcal vaccination in reducing morbidity and mortality in people with cystic fibrosis.