Update in cystic fibrosis 2013

Non-Contrast-Enhanced Functional Lung MRI to Evaluate Treatment Response of Allergic Bronchopulmonary Aspergillosis in Patients With Cystic Fibrosis: A Pilot Study

BACKGROUND

Allergic bronchopulmonary aspergillosis (ABPA) in cystic fibrosis (CF) patients is associated with severe lung damage and requires specific therapeutic management. Repeated imaging is recommended to both diagnose and follow-up response to treatment of ABPA in CF. However, high risk of cumulative radiation exposure requires evaluation of free-radiation techniques in the follow-up of CF patients with ABPA.

PURPOSE

To evaluate whether Fourier decomposition (FD) functional lung MRI can detect response to treatment of ABPA in CF patients.

STUDY TYPE

Retrospective longitudinal.

POPULATION

Twelve patients (7M, median-age:14 years) with CF and ABPA with pre- and post-treatment MRI.

FIELD STRENGTH/SEQUENCE

2D-balanced-steady-state free-precession (bSSFP) sequence with FD at 1.5T.

ASSESSMENT

Ventilation-weighted (V) and perfusion-weighted (Q) maps were obtained after FD processing of 2D-coronal bSSFP time-resolved images acquired before and 3-9 months after treatment. Defects extent was assessed on the functional maps using a qualitative semi-quantitative score (0 = absence/negligible, 1 = <50%, 2 = >50%). Mean and coefficient of variation (CV) of the ventilation signal-intensity (VSI) and the perfusion signal-intensity (QSI) were calculated. Measurements were performed independently by three readers and averaged. Inter-reader reproducibility of the measurements was assessed. Pulmonary function tests (PFTs) were performed within 1 week of both MRI studies as markers of the airflow-limitation severity.

STATISTICAL TESTS

Comparisons of medians were performed using the paired Wilcoxon-test. Reproducibility was assessed using intraclass correlation coefficient (ICC). Correlations between MRI and PFT parameters were assessed using the Spearman-test (rho correlation-coefficient). A P-value <0.05 was considered as significant.

RESULTS

Defects extent on both V and Q maps showed a significant reduction after ABPA treatment (4.25 vs. 1.92 for V-defect-score and 5 vs. 2.75 for Q-defect-score). VSI_mean was significantly increased after treatment (280 vs. 167). Qualitative analyses reproducibility showed an ICC > 0.90, while the ICCs of the quantitative measurements was almost perfect (>0.99). Changes in VSI_cv and QSI_cv before and after treatment correlated inversely with changes of FEV1%p (rho = -0.68 for both).

DATA CONCLUSION

Non-contrast-enhanced FD lung MRI has potential to reproducibly assess response to treatment of ABPA in CF patients and correlates with PFT obstructive parameters.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 3.

Diagnosis and Management of Cystic Fibrosis Exacerbations

With the improving survival of cystic fibrosis (CF) patients and the advent of highly effective cystic fibrosis transmembrane conductance regulator (CFTR) therapy, the clinical spectrum of this complex multisystem disease continues to evolve. One of the most important clinical events for patients with CF in the course of this disease is acute pulmonary exacerbation (PEx). Clinical and microbial epidemiology studies of CF PEx continue to provide important insight into the disease course, prognosis, and complications. This work has now led to several large-scale clinical trials designed to clarify the treatment paradigm for CF PEx. The primary goal of this review is to provide a summary and update of the pathophysiology, clinical and microbial epidemiology, outcome and treatment of CF PEx, biomarkers for exacerbation, and the impact of highly effective modulator therapy on these events moving forward.

Drugs, Drugs, Drugs: Current Treatment Paradigms in Cystic Fibrosis Airway Infections

Airway infections have remained a prominent feature in persons living with cystic fibrosis (CF) despite the dramatic improvements in survival in the past decades. Antimicrobials are a cornerstone of infection management for both acute and chronic maintenance indications. Historic clinical trials of antimicrobials in CF have led to the adoption of consensus guidelines for their use in clinical care. More recently, however, there are efforts to re-think the optimal use of antimicrobials for care with the advent of novel and highly effective CF transmembrane conductance regulator modulator therapies. Encouragingly, however, drug development has remained active concurrently in this space. Our review focuses on the evidence for and perspectives regarding antimicrobial use in both acute and maintenance settings in persons with CF. The therapeutic innovations in CF and how this may affect antimicrobial approaches are also discussed.

A Randomized Trial of Antimicrobial Duration for Cystic Fibrosis Pulmonary Exacerbation Treatment

RATIONALE

People with cystic fibrosis (CF) experience acute worsening of respiratory symptoms and lung function known as pulmonary exacerbations. Treatment with intravenous antimicrobials is common; however, there is scant evidence to support a standard treatment duration.

OBJECTIVE

Test differing durations of intravenous antimicrobials for CF exacerbations.

METHODS

STOP2 was a multi-center, randomized, controlled, clinical trial in exacerbation among adults with CF. After 7-10-days of treatment, participants exhibiting pre-defined lung function and symptom improvements were randomized to 10- or 14-days total antimicrobial duration; all others were randomized to 14- or 21-days.

MEASUREMENTS

The primary outcome was percent predicted forced expiratory volume in 1 second (ppFEV1) change from treatment initiation to two weeks after cessation. Among early responders non-inferiority of 10-days to 14-days was tested; superiority of 21-days compared to 14-days was compared for the others. Symptoms, weight, and adverse events were secondary.

RESULTS

Among 982 randomized, 277 met improvement criteria and were randomized to 10- or 14-days treatment; the remaining 705 received 21- or 14-days. Mean ppFEV1 change was 12.8 and 13.4 for 10- and 14-days, respectively, a ‒0.65 difference [95%CI ‒3.3, 2.0], excluding the pre-defined noninferiority margin. The 21- and 14-day arms experienced 3.3 and 3.4 mean ppFEV1 changes, a difference of ‒0.10 [‒1.3, 1.1]. Secondary endpoints and sensitivity analyses were supportive.

CONCLUSIONS

Among CF adults with early treatment improvement during exacerbation, ppFEV1 after 10-days of intravenous antimicrobials is not inferior to 14-days. For those with less improvement after one week, 21-days is not superior to 14-days. Clinical trial registration available at www.clinicaltrials.gov, ID: NCT02781610.

Clinical application of ultrashort echo-time MRI for lung pathologies in children

Lung magnetic resonance imaging (MRI) is considered to be challenging, because the low proton density of the tissue, fast signal decay, and respiratory artefacts hamper adequate image quality. MRI of the lungs and thorax is increasingly used in the paediatric population, because it is a radiation-free alternative to chest CT. Recently, ultrashort echo-time (UTE) sequences have been introduced into clinical MRI protocols, in order to improve the contrast-to-noise ratio due to reduced susceptibility artefacts and to depict structural alterations comparable to CT. The purpose of this review is to provide an overview of various clinical conditions and pathologies in the paediatric chest depicted by an UTE sequence, the so-called three-dimensional (3D) Cones sequence, in comparison with conventional MRI sequences. Besides describing typical features of cystic fibrosis, we present UTE application in other more or less common paediatric lung pathologies, for instance, interstitial pneumopathies, pulmonary infections, and congenital pulmonary malformations.

Brave New Lungs: Aging in the Shadow of COVID-19

As the COVID-19 pandemic continues to affect communities worldwide, this novel disease is leaving many survivors with severe lung damage. Among older patients, advanced lung damage is more likely. Survivors of all ages who have extensive lung impacts are likely to be new to managing those issues. Supporting healthy aging for these patients will require both gathering data about their unique experiences and using the existing evidence basis about adapting to managing obstructive lung disease. This article outlines key priorities for research with COVID-19 survivors aging with permanent lung damage and highlights unique considerations for people older at age of onset. It also outlines the relevance of findings from this research for clinical care supporting people newly aging with advanced lung disease from COVID-19. In the process, it summarizes lessons from established patient populations aging with progressive lung disease-using cystic fibrosis as a prominent example from the author's lived experience-that may enhance the experiences of older COVID-19 survivors.

The Clinical Use of Lung MRI in Cystic Fibrosis: What, Now, How?

To assess airway and lung parenchymal damage noninvasively in cystic fibrosis (CF), chest MRI has been historically out of the scope of routine clinical imaging because of technical difficulties such as low proton density and respiratory and cardiac motion. However, technological breakthroughs have emerged that dramatically improve lung MRI quality (including signal-to-noise ratio, resolution, speed, and contrast). At the same time, novel treatments have changed the landscape of CF clinical care. In this contemporary context, there is now consensus that lung MRI can be used clinically to assess CF in a radiation-free manner and to enable quantification of lung disease severity. MRI can now achieve three-dimensional, high-resolution morphologic imaging, and beyond this morphologic information, MRI may offer the ability to sensitively differentiate active inflammation vs scarring tissue. MRI could also characterize various forms of inflammation for early guidance of treatment. Moreover, functional information from MRI can be used to assess regional, small-airway disease with sensitivity to detect small changes even in patients with mild CF. Finally, automated quantification methods have emerged to support conventional visual analyses for more objective and reproducible assessment of disease severity. This article aims to review the most recent developments of lung MRI, with a focus on practical application and clinical value in CF, and the perspectives on how these modern techniques may converge and impact patient care soon.

Acute Pulmonary Exacerbations in Cystic Fibrosis

With the improving survival of cystic fibrosis (CF) patients and the advent of highly effective cystic fibrosis transmembrane conductance regulator therapy, the clinical spectrum of this complex multisystem disease continues to evolve. One of the most important clinical events for patients with CF in the course of this disease is an acute pulmonary exacerbation. Clinical and microbial epidemiology studies of CF pulmonary exacerbations continue to provide important insight into the disease course, prognosis, and complications. This work has now led to a number of large scale clinical trials with the goal of improving the treatment paradigm for CF pulmonary exacerbation. The primary goal of this review is to provide a summary of the pathophysiology, the clinical epidemiology, microbial epidemiology, outcome and the treatment of CF pulmonary exacerbation.

Adherence to Nutritional Supplementation in Cystic Fibrosis

PURPOSE

The purpose of this study was to examine patterns of adherence to a novel dietary supplement in pediatric cystic fibrosis. Adherence to dietary supplementation in cystic fibrosis is challenging, and examination of patterns of adherence behavior over time is needed to better characterize subgroups of patients who need self-management support.

DESIGN AND METHODS

We prospectively examined adherence to Lym-X-Sorb™ (LXS), an organized lipid matrix dietary supplementation for patients with cystic fibrosis (CF) and pancreatic insufficiency (PI), over a 12-month period. Adherence for participants aged 5-17 years with CF and PI (N = 109) was monitored monthly via supplement packet counts. Group-based trajectory modeling was employed to examine patterns in adherence behavior over time.

RESULTS

Four distinct trajectories best characterized adherence in this sample, with 18% of participants demonstrating near perfect adherence, 42% demonstrating good adherence (at or above 80%), 16% demonstrating poor adherence that declined over time, and 24% demonstrating significant non-adherence (< 30%).

CONCLUSIONS

Some patients with CF and PI who are prescribed nutritional supplements will require intensive, individualized behavioral intervention to enhance adherence. Identifying patients who will have difficulty adhering to dietary interventions may result in better treatment-to-patient matching and improved adherence promotion efforts.

PRACTICE IMPLICATIONS

Assessment of adherence to dietary supplementation over time can identify patients at risk for continued difficulty with self-management and provide opportunities for early intervention.

Congenital pulmonary airway malformation

Congenital pulmonary airway malformation (CPAM) is a developmental malformation of the lower respiratory tract. We report the case of a male newborn diagnosed with cystic lung disease during prenatal ultrasound. A cesarean section was performed at the 32nd gestational week because of premature rupture of the membranes, and soon after the delivery the newborn developed respiratory failure and died. The aim of this study is to report an autopsy case because of its rarity, and to briefly discuss the CPAM subtypes and differential diagnosis of cystic lung diseases of childhood.

The experience of men and women with cystic fibrosis who have become a parent: A qualitative study

AIMS AND OBJECTIVES

To explore the experiences of men and women with cystic fibrosis in becoming parents.

BACKGROUND

As lifespan for people with cystic fibrosis increases, and reproductive technology advances, having a child of their own becomes a possibility.

DESIGN

This study used a phenomenological framework.

METHODS

Seven Australian adults with cystic fibrosis were invited to describe their experiences of becoming parents in the context of a semi-structured interview. Analysis of the data involved highlighting recurrent phrases and isolating emergent themes.

RESULTS

Two overarching themes characterised the participants' experience: Counting the cost, as they recalled Concentric communication and Pathways to pregnancy; and Living the dream, as they cast a retrospective view over this, their major achievement, in the light of their Reaction: a dream comes true, Coping: a question of balance, Conjecture: the future redefined and Confidence: recalibrating.

CONCLUSIONS

While advances in cystic fibrosis care and reproductive technology have increased the possibility of individuals with cystic fibrosis becoming parents, the passage to becoming a parent is a complex process.

RELEVANCE TO CLINICAL PRACTICE

These findings can inform health professionals to support the adaptive work necessary for families that include members with cystic fibrosis. A contemporary understanding of this phenomenon is necessary for facilitating clinically relevant communication.

Maintaining mental health and function for the long run in cystic fibrosis

Research shows that individuals with cystic fibrosis (CF) and their families experience significant emotional morbidity. In addition to distress, worry, and grief, high rates of clinically significant symptoms of depression and anxiety have been found in both individuals with CF and parents. These disorders have a major impact on the person's functioning, and that of their family, and adversely impact the capacity to cope with the burden of CF and adhere to prescribed treatments. Despite growing recognition that mental health care is an essential component of comprehensive CF care, evidence suggests many patients and their families do not receive needed support and mental health interventions. Clinical practice guidelines for screening and treating depression and anxiety in individuals with CF have been developed by The Cystic Fibrosis Foundation and the European Cystic Fibrosis Society in response to this need. This review highlights that the optimum care for individuals with CF and their families incorporates mental health in routine CF care. Addressing mental health could substantially improve physical and mental health outcomes and the functioning of individuals with CF and their families. Pediatr Pulmonol. 2016;51:S71-S78. © 2016 Wiley Periodicals, Inc.

Characterizing Lung Disease in Cystic Fibrosis with Magnetic Resonance Imaging and Airway Physiology

Translational investigations in cystic fibrosis (CF) have a need for improved quantitative and longitudinal measures of disease status. To establish a non-invasive quantitative MRI technique to monitor lung health in patients with CF and correlate MR metrics with airway physiology as measured by multiple breath washout (MBW). Data were collected in 12 CF patients and 12 healthy controls. Regional (central and peripheral lung) measures of fractional lung water density (FLD: air to 100% fluid) were acquired both at FRC and TLC on a 1.5T MRI. The median FLD (mFLD) and the FRC-to-TLC mFLD ratio were calculated for each region at both lung volumes. Spirometry and MBW data were also acquired for each subject. Ventilation inhomogeneities were quantified by the lung clearance index (LCI) and by indices S_cond* and S_acin* that assess inhomogeneities in the conducting (central) and acinar (peripheral) lung regions, respectively. MBW indices and mFLD at TLC (both regions) were significantly elevated in CF (p<0.01) compared to controls. The mFLD at TLC (central: R = 0.82) and the FRC-to-TLC mFLD ratio (peripheral: R = -0.77) were strongly correlated with S_cond* and LCI. CF patients had high lung water content at TLC when compared to controls. This is likely due to the presence of retained airway secretions and airway wall edema (more water) and to limited expansions of air trapping areas (less air) in CF subjects. FRC-to-TLC ratios of mFLD strongly correlated with central ventilation inhomogeneities. These combined measures may provide a useful marker of both retained mucus and air trapping in CF lungs.

Cystic fibrosis - characterization of the adult population in Portugal

INTRODUCTION

The incidence of cystic fibrosis (CF) in Portugal is estimated at 1:8000 live births, although there is a lack of accurate statistics. The average life expectancy has been steadily increasing and CF is no longer an exclusively pediatric disease.

OBJECTIVES

Characterize the Portuguese adult population with the diagnosis of CF.

METHODS

Retrospective study based on clinical data of adult CF follow-up patients in the three specialized centers in Portugal where all of CF patients are seen, during 2012.

RESULTS

In 2012, there were 89 follow-up patients, 48 (54%) female and 15 (17%) lung transplanted. The average age was 31.3±9 years. The median age at diagnosis was 13 years and 34 (38%) were diagnosed in adulthood. The most frequent mutation was F508del (54.9%). Of the 89 patients, 49 patients (56%) had pancreatic insufficiency, 7 (9%) were diabetic and 42 patients (47.7%) had a body mass index (BMI) <20kg/m(2). As to ventilatory function, the average value of the forced expiratory volume in 1s (FEV1) was 58.45±28.59%. Only one of 77 patients did not have chronic airway infection. The most commonly isolated germ was methicillin-sensitive Staphylococcus aureus in 49 patients (55%). During 2012, two patients (2.2%) died at the ages of 21 and 36 years.

DISCUSSION

This study is the first description of the Portuguese adult CF population, which is particularly important since it can give us a better understanding of the real situation. A significant percentage of these patients were diagnosed in adulthood, which highlights the need for diagnostic suspicion in a patient with chronic lung disease and atypical manifestations.

Lung morphology assessment of cystic fibrosis using MRI with ultra-short echo time at submillimeter spatial resolution

OBJECTIVES

We hypothesized that non-contrast-enhanced PETRA (pointwise encoding time reduction with radial acquisition) MR (magnetic resonance) sequencing could be an alternative to unenhanced computed tomography (CT) in assessing cystic fibrosis (CF) lung structural alterations, as well as compared agreements and concordances with those of conventional T1-weighted and T2-weighted sequences.

MATERIAL AND METHODS

Thirty consecutive CF patients completed both CT and MRI the same day. No contrast injection was used. Agreement in identifying structural alterations was evaluated at the segmental level using a kappa test. Intraclass correlation coefficients (ICC) and Bland-Altman analysis were used to assess concordances and reproducibility in Helbich-Bhalla disease severity scoring.

RESULTS

Agreement between PETRA and CT was higher than that of T1- or T2-weighted sequences, notably in assessing the segmental presence of bronchiectasis (Kappa = 0.83; 0.51; 0.49, respectively). The concordance in Helbich-Bhalla scores was very good using PETRA (ICC = 0.97), independently from its magnitude (mean difference (MD) = -0.3 [-2.8; 2.2]), whereas scoring was underestimated using both conventional T1 and T2 sequences (MD = -3.6 [-7.4; 0.1]) and MD = -4.6 [-8.2; -1.0], respectively). Intra- and interobserver reproducibility were very good for all imaging modalities (ICC = 0.86-0.98).

CONCLUSION

PETRA showed higher agreement in describing CF lung morphological changes than that of conventional sequences, whereas the Helbich-Bhalla scoring matched closely with that of CT.

KEY POINTS

• Spatial resolution of lung MRI is limited using non-ultra-short TE MRI technique • Ultra-short echo time (UTE) technique enables submillimeter 3D-MRI of airways • 3D-UTE MRI shows very good concordance with CT in assessing cystic fibrosis • Radiation-free 3D-UTE MRI enables the Helbich-Bhalla scoring without a need for contrast injection.

Analysis and Characterization of Staphylococcus aureus Small Colony Variants Isolated From Cystic Fibrosis Patients in Austria

Cystic fibrosis (CF) is the most common hereditary lung disease in the Caucasian population, characterized by viscous bronchial secretion, consecutive defective mucociliary clearance, and unavoidable colonization with microorganisms. Besides Pseudomonas aeruginosa, Staphylococcus aureus is the most common bacterial species colonizing the CF respiratory tract. Under antibiotic pressure S. aureus is able to switch to small colony variants (SCV). These small colony variants can invade epithelial cells, overcome antibiotic therapy inside the cells and can be the starting point for extracellular recolonization. The aim of the present study was the isolation and characterization of S. aureus small colony variants from Austrian cystic fibrosis patients. Samples collected from 147 patients were screened for the presence of S. aureus wild-type and small colony variants. Antibiotic susceptibility testing and determination of the small colony variants causing auxotrophism were performed. Wild-type isolates were assigned to corresponding small colony variants with spa typing. In total, 17 different small colony variant isolates and 12 corresponding wild-type isolates were obtained. 13 isolates were determined thymidine auxotroph, 2 isolates were auxotroph for hemin, and none of the tested isolates was auxotroph for both, respectively. The presence of SCVs is directly related to a poor clinical outcome, therefore a monitoring of SCV prevalence is recommended. This study revealed rather low SCV ratios in CF patients compared to other countries.

Acquired Cystic Fibrosis Transmembrane Conductance Regulator Dysfunction in Chronic Bronchitis and Other Diseases of Mucus Clearance

Chronic obstructive pulmonary disease (COPD) is a major public health problem. No therapies alter the natural history of the disease. Chronic bronchitis is perhaps the most clinically troublesome phenotype. Emerging data strongly suggest that cigarette smoke and its components can lead to acquired cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction. Findings in vitro, in animal models, and in smokers with and without COPD also show acquired CFTR dysfunction, which is associated with chronic bronchitis. This abnormality is also present in extrapulmonary organs, suggesting that CFTR dysfunction may contribute to smoking-related systemic diseases.

Recent advances in understanding and managing cystic fibrosis transmembrane conductance regulator dysfunction

Cystic fibrosis is the most common autosomal recessive genetic disease in Caucasians and has been extensively studied for many decades. The cystic fibrosis transmembrane conductance regulator gene was identified in 1989. It encodes a complex protein which has numerous cellular functions. Our understanding of cystic fibrosis pathophysiology and genetics is constantly expanding and being refined, leading to improved management of the disease and increased life expectancy in affected individuals.

F508del-cystic fibrosis transmembrane regulator correctors for treatment of cystic fibrosis: a patent review

INTRODUCTION

Cystic fibrosis (CF) is an autosomal recessive genetic disease caused by malfunction of CF transmembrane regulator (CFTR). The deletion of a phenylalanine at residue 508 (F508del) is the most common mutation that causes cellular processing, chloride channel gating and protein stability defects in CFTR. Pharmacological modulators of F508del-CFTR, aimed at correcting the cellular processing defect (correctors) and the gating defect (potentiators) in CFTR protein, are regarded as promising therapeutic agents for CF disease. Endeavors in searching F508del-CFTR modulators have shown encouraging results, with several small-molecule compounds having entered clinical trials or even represented clinical options.

AREAS COVERED

This review covers the discovery of F508del-CFTR correctors described in both patents (2005 - present) and scientific literatures.

EXPERT OPINION

Cyclopropane carboxamide derivatives of CFTR correctors continue to dominate in this area, among which lumacaftor (a NBD1-MSD1/2 interface stabilizer) is the most promising compound and is now under the priority review by US FDA. However, the abrogation effect of ivacaftor (potentiator) on lumacaftor suggests the requirement of discovering new correctors and potentiators that can cooperate well. Integration screening for simultaneously identifying combinations of correctors (particularly NBD1 stabilizer) and potentiators should provide an alternative strategy. A recently reported natural product fraction library may be useful for the integration screening.

WITHDRAWN: The future of lung transplantation

This article has been withdrawn for editorial reasons because the journal will be published only in English. In order to avoid duplicated records, this article can be found at http://dx.doi.org/10.1016/j.rppnen.2014.09.006. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.