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Background: Both nasal obstruction and sleep disturbance are common in patients with cystic fibrosis (CF). In patients with obstructive sleep apnea (OSA), studies suggest that these conditions are related and that nasal congestion improves with CPAP therapy. We hypothesized that subjects admitted to hospital for therapy of an exacerbation of CF would have both nasal symptoms and sleep disturbance and that these would improve with the initiation of nocturnal high-flow nasal cannula therapy (HFNC)., Methods: Twenty-five subjects with an exacerbation of CF were enrolled to randomly receive either 5 d of nocturnal HFNC at 20 L/min in the treatment group or 5 L/min of nocturnal nasal cannula air at ambient temperature and humidity in the low-flow group. On the first and last day of the study, the Sino-Nasal Outcome Test (SNOT-20) was administered to evaluate nasal symptoms, and sleep quality was measured using the Actiwatch 2., Results: Fifteen subjects completed the study (6 HFNC, 9 low flow). We confirmed that subjects had significant sleep disturbance that did not improve over the 5 d of the study. Subjects also had disturbing nasal symptoms that significantly improved only in those receiving HFNC (pre 14 [20] vs post 6 [13], P = .027)., Conclusions: Similar to what has been reported in older subjects with OSA, nocturnal HFNC improves sinonasal symptoms in subjects with an exacerbation of CF. There was no measurable effect on sleep quality, which may be due to the short duration of the study, or to subjects being evaluated while being treated in a hospital setting., Competing Interests: Dr Davis is funded by NIH/NHLBI PO1 HL128192 and the Indiana CTSI UL 1 TR002529. Dr Davis is a patent holder of Optate. Dr Davis discloses a relationship with Airbase Breathing Company. The remaining authors have disclosed no conflicts of interest., (Copyright © 2023 by Daedalus Enterprises.)

Airway mucus is a complex viscoelastic gel that provides a defensive physical barrier and shields the airway epithelium by trapping inhaled foreign pathogens and facilitating their removal via mucociliary clearance (MCC). In patients with respiratory diseases, such as chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), non-CF bronchiectasis, and asthma, an increase in crosslinking and physical entanglement of mucin polymers as well as mucus dehydration often alters and typically reduces mucus mesh network pore size, which reduces neutrophil migration, decreases pathogen capture, sustains bacterial infection, and accelerates lung function decline. Conventional aerosol particles containing hydrophobic drugs are rapidly captured and removed by MCC. Therefore, it is critical to design aerosol delivery systems with the appropriate size and surface chemistry that can improve drug retention and absorption with the goal of increased efficacy. Biodegradable muco-adhesive particles (MAPs) and muco-penetrating particles (MPPs) have been engineered to achieve effective pulmonary delivery and extend drug residence time in the lungs. MAPs can be used to target mucus as they get trapped in airway mucus by steric obstruction and/or adhesion. MPPs avoid muco-adhesion and are designed to have a particle size smaller than the mucus network, enhancing lung retention of particles as well as transport to the respiratory epithelial layer and drug absorption. In this review, we aim to provide insight into the composition of airway mucus, rheological characteristics of airway mucus in healthy and diseased subjects, the most recent techniques to study the flow dynamics and particle diffusion in airway mucus (in particular, multiple particle tracking, MPT), and the advancements in engineering MPPs that have contributed to improved airway mucus penetration, lung distribution, and retention., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The EEG aerosol technologies described in this publication have been filed as patent applications through Virginia Commonwealth University (VCU). Michael Hindle and Worth Longest are the co-inventors, which are subject to certain rules and restrictions under VCU policy. The terms of this arrangement are being managed by VCU in accordance with its conflict of interest policies., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Cystic fibrosis (CF) lung disease is marked by high concentrations of neutrophil elastase (NE) and DNA polymers; both factors contribute to airway disease. Although inhaled recombinant human dornase alfa reduces the frequency of CF pulmonary exacerbations, it also increases free NE activity in the sputum. There are no approved anti-NE therapies for patients with CF. We investigated whether synthetic, low-molecular weight polysulfated hyaluronan GlycoMira-1111 (GM-1111) would be effective as an anti-NE drug using ex vivo CF sputum. Anti-NE activity of GM-1111 was tested in CF sputum in the presence or absence of dornase alfa and/or hypertonic saline using a spectrophotometric assay specific for human NE and was compared with unfractionated heparin. We tested whether GM-1111 disaggregated DNA from CF sputum (using gel electrophoresis analysis) or modified CF sputum viscoelastic properties (using a dynamic rheometer). GM-1111 and unfractionated heparin had near equivalent anti-NE activity in CF sputum in the presence of dornase alfa. Both GM-1111 and unfractionated heparin retained anti-NE activity in hypertonic saline but with decreased activity. GM-1111 increased the release of soluble DNA in CF sputum, resulting in improved depolymerization efficacy of dornase alfa. GM-1111 decreased CF sputum elasticity. GM-1111 inhibited NE activity, enhanced DNA depolymerization by deoxyribonuclease, and decreased viscoelastic properties of CF sputum, similar to effects reported previously for unfractionated heparin. Unlike heparins, GM-1111 is synthetic, with minimal anticoagulant activity, and is not derived from animal products. These key attributes provide advantages over unfractionated heparin as a potential therapeutic for CF.

Many airway diseases in children, notably bronchiolitis, cystic fibrosis (CF), non-CF bronchiectasis including primary ciliary dyskinesia, pneumonia, and severe asthma are associated with retention of airway secretions. Medications to improve secretions clearance, the mucoactive medications, are employed to treat these diseases with varying degrees of success. This manuscript reviews evidence for the use of these medications and future directions of study., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Tenacious sputum poses a critical diffusion barrier for aerosol antibiotics used to treat cystic fibrosis (CF) lung infection. We conducted a proof-of-concept study using dense poly(ethylene glycol) coated polystyrene nanoparticles (PS-PEG NPs) as model muco-inert particles (MIPs) formulated as a powder using an excipient enhanced growth (EEG) strategy, aiming to minimize extrathoracic airway loss, maximize deposition in the airway and further overcome the sputum barrier in the CF lungs. The EEG aerosol formulation containing PS-PEG MIPs was prepared by spray drying and produced discrete spherical particles with geometric diameter of approximately 2 μm; and >80% of the powder dose was delivered from a new small-animal dry powder inhaler (DPI). The MIPs released from the EEG aerosol had human airway mucus and CF sputum diffusion properties comparable to the suspension formulation. These properties make this formulation a promising pulmonary drug delivery system for CF lung infections., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Cystic fibrosis (CF) is a multifactorial disease in which dysfunction of protease-antiprotease balance plays a key role. The current CF therapy relies on dornase α, hypertonic saline, and antibiotics and does not address the high neutrophil elastase (NE) activity observed in the lung and sputum of CF patients. Our hypothesis is that variants of heparin, which potently inhibit NE but are not anticoagulant, would help restore the protease-antiprotease balance in CF. To realize this concept, we studied molecular principles governing the effectiveness of different heparins, especially 2- O ,3- O -desulfated heparin (ODSH), in the presence of sputum components and therapeutic agents. Using sputa from CF patients and an NE activity assay, we found that heparins are ineffective if used in the absence of dornase. This is true even when mucolytics, such as DTT or N -acetylcysteine, were used. Computational modeling suggested that ODSH and DNA compete for binding to an overlapping allosteric site on NE, which reduces the anti-NE potential of ODSH. NE inhibition of both DNA and ODSH is chain length-dependent, but ODSH chains exhibit higher potency per unit residue length. Likewise, ODSH chains exhibit higher NE inhibition potential compared with DNA chains in the presence of saline. These studies suggest fundamental differences in DNA and ODSH recognition and inhibition of NE despite engaging overlapping sites and offer unique insights into molecular principles that could be used in developing antiprotease agents in the presence of current treatments, such as dornase and hypertonic saline., (© 2018 Kummarapurugu et al.)

Background: Cystic fibrosis (CF) airway secretions are abnormal, contributing to decreased clearance and a cycle of infection and inflammation. CF sputum properties may predict disease progression. We hypothesized that sputum viscoelasticity and clearance abnormalities would inversely correlate with pulmonary function during exacerbation and that sputum properties would return to baseline after therapy., Methods: We collected sputa longitudinally from 13 subjects with CF with moderate to severe lung disease during both clinical stability and exacerbation. Dynamic rheology was analyzed, using a cone-and-plate rheometer. Mucociliary clearability was measured on mucus-depleted frog palate, cough clearability in a simulated cough machine, and sputum hydration as percent solids was measured following lyophilization., Results: Elastic modulus G' and viscous modulus G'' increased during exacerbation and returned to baseline levels with recovery (P < .05 for both). Solid content did not change. Sputum mucociliary clearability decreased during exacerbations (P < .01) but not cough clearance. FEV 1 % predicted was inversely correlated with G' and G'' (P < .01 for both). The regression slope of the natural log-transformed G' and G'' vs FEV 1 % predicted was statistically homogeneous among subjects (estimated common slope m = -3.84, P < .001 and m = -8.53, P < .0001, respectively)., Conclusions: Among these subjects with CF, there is a striking identity of the slope defining the relationship between ln G' or ln G'' and FEV 1 . There are dramatic increases in dynamic viscosity and elasticity during a pulmonary exacerbation with return to baseline at recovery. This suggests that sputum viscoelastic properties are tightly associated with lung function and disease status., (Copyright © 2018 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

The respiratory epithelium is lined by mucus, a gel consisting of water, ions, proteins, and macromolecules. The major macromolecular components of mucus are the mucin glycoproteins, which are critical for local defense of the airway. There are three classes of mucins in the airways: those that are secreted but do not polymerize (MUC7), those that are secreted and polymerize to form gels (MUC5AC, MUC5B), and those that have transmembrane domains and are cell surface associated (MUC1, MUC4, MUC16, MUC20). The mucins are regulated at the transcriptional, posttranscriptional, and epigenetic levels, and posttranslational modifications play an important role in mucin binding and clearance of microbes and pollutants. The development of mice deficient in specific mucins, and the cystic fibrosis pig, has greatly advanced our understanding of the role of mucins as innate immune mediators and how mucins and mucus contribute to lung disease. These observations suggest new strategies to ameliorate mucus obstruction by targeting mucociliary clearance and mucin hyperconcentration. Furthermore, a polymorphism in the promoter of MUC5B is strongly associated with risk of developing pulmonary fibrosis, supporting a novel function for MUC5B to influence interstitial lung disease. Exciting new data support the concept not only that mucins and mucus are important for lung homeostasis and protection from environmental threats but also that goblet cells play an important role as regulators of innate immune function. These insights into the innate immune properties of mucins and goblet cells support a shift from the current paradigm of repressing increased mucin expression to targeting regulation of specific mucins and the abnormal airway milieu., (Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Introduction: Sphingolipids are associated with the regulation of pulmonary inflammation. Although sphingolipids have been investigated in the context of cystic fibrosis (CF), the focus has been on loss of CF transmembrane conductance regulator (CFTR) function in mice, and in CF human lung epithelial cell lines. The sphingolipid content of CF sputum and the potential link between ceramide and airway inflammation in CF remain relatively unexplored., Methods: Fifteen patients with CF provided two spontaneously expectorated sputum samples, one collected during a hospitalization for an acute pulmonary exacerbation and one from an outpatient visit at a time of clinical stability. Sputum was processed, and the supernatant assessed for active neutrophil elastase (NE) using a chromogenic microplate assay and sphingolipid content using reverse phase high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). Relevant demographic data including age, sex, CF genotype, FEV 1 % predicted, and sputum bacteriology were assessed as possible modifying factors that could influence the correlation between NE and sputum sphingolipids. Data were analyzed for linear correlation, with statistical significance pre-defined as P < 0.05., Results: There was a significant association between the concentration of active NE and ceramide, sphingomyelin, and monohexosylceramide moieties as well as sphingosine-1-phosphate. The presence of Methicillin-resistant Staphylococcus aureus (MRSA), FEV 1 % predicted, and female gender further strengthened the association of NE and sphingolipids, but Pseudomonas aeruginosa had no effect on the association between NE and sphingolipids., Conclusions: These data suggest that NE may increase pro-inflammatory sphingolipid signaling, and the association is strengthened in female patients and patients with MRSA., (© 2018 Wiley Periodicals, Inc.)

Introduction: Cystic fibrosis (CF) is a multisystem illness caused by abnormalities in the CF transmembrane conductance regulator (CFTR) gene and protein. CFTR is an ion channel regulating transport of chloride, bicarbonate, and water, and influencing sodium resorption. It is inherited as an autosomal recessive disorder, and with about 70,000 CF patients worldwide, it is the most common life shortening disease among persons of European descent. CFTR disease-causing mutations have been organized into six classes. :, Areas Covered: Recently, small molecule targeted therapy for specific classes of CFTR abnormalities have included CFTR correctors that decrease protein degradation and CFTR potentiators that increase channel open probability enhancing chloride transport., Expert Opinion: Although there are many novel medications in preclinical and clinical testing, there is need for safe and effective CFTR modulating drugs and immunomodulatory medications to decrease the abundant neutrophilic inflammation response in the airway without unwanted adverse effects. Thymosin alpha 1 treatment of airway cells isolated from phe508del CF patients and from CF knockout mice, decreased inflammation, increased CFTR maturation, and facilitated translocation of CFTR protein to the plasma membrane increasing channel activity. If similar results are seen in humans with CF, thymosin alpha 1 has the unique potential to be a single molecule therapy for treating CF airway disease.

It is always an exciting challenge to write a Year in Review artcicle identifying the best publications in the preceding year; in this case from October 2016 until the AARC meeting in October 2017. This is particularly true for cystic fibrosis (CF), where there has been an explosion of new data, new medications, and new understanding of the pathophysiology of the disease. PubMed lists more than 2,500 papers published during those 12 months, many of them outstanding. I am indebted to many colleagues and friends who are leaders in the CF community, active readers of the pediatric pulmonary listserv, and scientists and clinicians engaged in the care of CF, for offering their suggestions regarding which articles should be included in this review. I believe that you will enjoy reading this curated selection of manuscripts that I have tried to organize by theme., Competing Interests: The author discloses no conflicts of interest., (Copyright © 2018 by Daedalus Enterprises.)

Background: Neutrophil elastase (NE) rapidly degrades gel-forming airway mucins in cystic fibrosis (CF) sputum. We hypothesized that KRP-109, a small molecule NE inhibitor, would inhibit CF mucin degradation in vitro., Methods: Sputa were collected from CF patients (n=5) chronically or intermittently infected with Pseudomonas aeruginosa (P.a.). Mucin degradation was analyzed using western blot. Protease inhibitor studies were performed using alpha1-proteinase inhibitor (A1-PI Prolastin®) and KRP-109. Elastase activity assays were performed using spectrophotometry., Results: There were significant differences in the amount of active NE in different CF sputum samples. KRP-109 decreased the NE driven mucin degradation in vitro. Pseudomonas elastases appeared to blunt elastase inhibition by A1-PI or KRP-109., Conclusion: Inhibitors of neutrophil and Pseudomonas-derived elastases might rescue mucus clearance and reverse airway obstruction in CF., (Copyright © 2015 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

As a student I recall being told that half of what we would learn in medical school would be proven to be wrong. The challenges were to identify the incorrect half and, often more challenging, be willing to give up our entrenched ideas. Myths have been defined as traditional concepts or practice with no basis in fact. A misunderstanding is a mistaken approach or incomplete knowledge that can be resolved with better evidence, while firmly established misunderstandings can become dogma; a point of view put forth as authoritative without basis in fact. In this paper, I explore a number of myths, mistakes, and dogma related to cystic fibrosis disease and care. Many of these are myths that have long been vanquished and even forgotten, while others are controversial. In the future, many things taken as either fact or "clinical experience" today will be proven wrong. Let us examine these myths with an open mind and willingness to change our beliefs when justified., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Background: Positive expiratory pressure (PEP) is used for airway clearance in cystic fibrosis (CF) patients. Hypertonic saline (HTS) aerosol increases sputum expectoration volume and may improve respiratory secretion properties. CPAP may also be used to maintain airway patency and mobilize secretions. To evaluate if CPAP would increase the beneficial clearance effect of HTS in subjects with CF, we investigated the effects of CPAP alone and CPAP followed by HTS on sputum physical properties and expectoration volume in CF subjects., Methods: In this crossover study, 15 CF subjects (mean age 19 y old) were randomized to interventions, 48 hours apart: directed coughs (control), CPAP at 10 cm H(2)O, HTS 7%, and both CPAP and HTS (CPAP+HTS). Sputum collection was performed at baseline and after interventions. Expectorated volume was determined and in vitro sputum properties were analyzed for contact angle and cough clearability., Results: There were no significant differences between any treatment in arterial blood pressure, heart rate, or pulse oximetry, between the 2 time points. HTS and CPAP+HTS improved cough clearability by 50% (P = .001) and expectorated volume secretion by 530% (P = .001). However, there were no differences between control and CPAP on sputum contact angle, cough clearability, or volume of expectorated secretion., Conclusions: CPAP alone had no effect on mucus clearance, sputum properties, or expectorated volume, and did not potentiate the effect of HTS alone in CF subjects.

The clinically significant actions of oral azithromycin in modifying progressive cystic fibrosis (CF) lung disease have been well documented. In vitro and clinical data suggests that clarithromycin has immunomodulatory properties similar to other 14-member macrolides, however two previously reported short term, open label trials of clairthromycin in small numbers of patients with CF failed to show significant benefits in modifying lung function or inflammation. We performed an international double blind, cross-over trial in which 63 subjects with CF were studied while receiving either placeo or 500 mg oral clarithromycin twice daily for 5 months, with a 1-month wash-out. The primary efficacy end point was the change in lung function (FEV(1) and FVC) during the clarithromycin treatment period compared to placebo treatment. Secondary efficacy end points included; quality of life, number of pulmonary exacerbations, height and weight, sputum inflammatory mediator content, sputum transportability and surface properties, bacterial flora, nasal potential difference, and breath condensate. No significant difference in either the primary efficacy end point or any secondary end point was seen during the period of clarithromycin treatment compared to those seen during placebo administration. We conclude that clarithromycin is not effective in treating CF lung disease., (Copyright © 2012 Wiley Periodicals, Inc.)

Bordetella bronchiseptica is a zoonotic respiratory pathogen commonly found in domesticated farm and companion animals, including dogs and cats. Here, we report isolation of B. bronchiseptica from a sputum sample of a cystic fibrosis patient recently exposed to a kitten with an acute respiratory illness. Genetic characterization of the isolate and comparison with other isolates of human or feline origin strongly suggest that the kitten was the source of infection., (© 2011 Blackwell Verlag GmbH.)

ABSTRACT As part of the innate and adaptive immune system, airway epithelial cells secrete proinflammatory cytokines after activation of Toll-like receptors (TLRs) by pathogens. Nevertheless, cystic fibrosis (CF) airways are chronically infected with Pseudomonas aeruginosa, suggesting a modified immune response in CF. The authors have shown that in CF bronchial epithelial cells, a reduced surface expression of TLR-4 causes a diminished interleukin (IL)-8 and IL-6 response upon lipopolysaccharide (LPS) stimulation. However, there is no information regarding activation of the MyD88 (myeloid differentiation primary response gene 88)-independent TLR-4 signaling pathway by LPS, which results in the activation of adaptive immune responses by secretion of the T cell-recruiting chemokine interferon-γ-inducible protein (IP)-10. Therefore, the authors investigated the induction of IP-10 in CF bronchial epithelial cell line CFBE41o- and its CFTR-corrected isotype under well-differentiating conditions. TLR-4 surface expression was significantly reduced in CFBE41o- by a factor of 2, compared to the CFTR-corrected cells. In CFTR-corrected cells, stimulation with LPS increased IP-10 secretion. Incubating cells with siRNA directed against TLR-4 inhibited the LPS stimulated increase of IP-10 in CFTR-corrected cells. The reduced TLR-4 surface expression in CF cells causes the loss of induction of IP-10 by LPS. This could compromise adaptive immune responses in CF due to a reduced T-cell recruitment.

Airway mucins are the major molecular constituents of mucus. Mucus forms the first barrier to invading organisms in the airways and is an important defense mechanism of the lung. We confirm that mucin concentrations are significantly decreased in airway secretions of subjects with cystic fibrosis (CF) who have chronic Pseudomonas aeruginosa infection. In sputum from CF subjects without a history of P. aeruginosa, we found no significant difference in the mucin concentration compared to mucus from normal controls. We demonstrate that mucins can be degraded by synthetic human neutrophil elastase (HNE) and P. aeruginosa elastase B (pseudolysin) and that degradation was inhibited by serine proteases inhibitors (diisopropyl fluorophosphates [DFP], phenylmethylsulfonyl fluoride [PMSF], and 1-chloro-3-tosylamido-7-amino-2-heptanone HCl [TLCK]). The mucin concentration in airway secretions from CF subjects is similar to that for normal subjects until there is infection by P. aeruginosa, and after that, the mucin concentration decreases dramatically. This is most likely due to degradation by serine proteases. The loss of this mucin barrier may contribute to chronic airway infection in the CF airway.

Background: Cystic fibrosis (CF) patients commonly use a high-frequency chest-wall compression (HFCWC) device for airway clearance that generates oscillatory flow with a sine-wave configuration. Typical HFCWC settings combine a lower Vest inflation pressure setting (eg, 5 on the Vest's arbitrary 1-10 scale for the setting that controls the background pressure of the inflatable vest) with mid-range frequency (14-16 Hz) (lower-pressure/mid-frequency HFCWC)., Objective: To determine whether HFCWC with higher pressure settings (6-10 on the Hill-Rom Vest's arbitrary 1-10 scale) combined with variable mid-frequencies (8, 9, and 10 Hz, plus 18, 19, and 20 Hz) (higher-pressure/variable-frequency HFCWC) results in greater sputum expectoration than lower-pressure/mid-frequency HFCWC., Methods: This was a controlled randomized crossover study. Sixteen clinically stable, adult CF patients participated. Patients performed airway clearance with HFCWC, once each with lower-pressure/mid-frequency HFCWC and higher-pressure/variable-frequency HFCWC, on separate occasions. All sputum produced during each session was collected. Patients completed pulmonary function tests before and after each session., Results: Median sputum wet weight was greater with higher-pressure/variable-frequency HFCWC than with lower-pressure/mid-frequency HFCWC (6.4 g, range 0.49-22.0 g, versus 4.8 g, range 0.24-15.0 g, P = .02). Dry sputum weight differences did not reach statistical significance (higher-pressure/variable-frequency HFCWC 0.20 g, range 0.009-0.62 g, lower-pressure/mid-frequency HFCWC 0.12 g, range 0.0001-1.0 g, P = .23). Higher-pressure/variable-frequency HFCWC and lower-pressure/mid-frequency HFCWC resulted in similar increases in FEV(1) (70 mL vs 90 mL, P = .21) and forced vital capacity (80 mL vs 80 mL, P = .94). Post-therapy sputum viscoelastic properties did not differ. Patients perceived the 2 regimens as equally comfortable and effective (P = .35 and P = .35, respectively)., Conclusions: In adult CF patients, single-session higher-pressure/variable-frequency HFCWC resulted in greater sputum expectoration by wet weight, but not other differences, compared to the commonly used lower-pressure/mid-frequency settings. Longer-term comparisons are needed in a larger, more diverse population to determine whether sustained use of the higher-pressure/variable-frequency settings results in clinically important differences in outcomes.

Airway epithelial cells contribute to the inflammatory response of the lung, and their innate immune response is primarily mediated via Toll-like receptor (TLR) signaling. Cystic fibrosis (CF) airways are chronically infected with Pseudomonas aeruginosa, suggesting a modified immune response in CF. We investigated the TLR-4 expression and the inflammatory profile (IL-8 and IL-6 secretion) in CF bronchial epithelial cell line CFBE41o- and its CF transmembrane ion condcutance regulator (CFTR)-corrected counterpart grown under air-liquid interface conditions after stimulation with lipopolysaccharide (LPS) from gram-negative bacteria. In CFTR-corrected cells, IL-8 and IL-6 secretions were constitutively activated but significantly increased after LPS stimulation compared with CFBE41o-. Blocking TLR-4 by a specific antibody significantly inhibited IL-8 secretion only in CFTR-corrected cells. Transfection with specific siRNA directed against TLR-4 mRNA significantly reduced the response to LPS in both cell lines. Fluorescence-activated cell sorter analysis revealed significantly higher levels of TLR-4 surface expression in CFTR-corrected cells. In histologic lung sections of patients with CF, the TLR-4 expression in the bronchial epithelium was significantly reduced compared with healthy control subjects. In CF the loss of CFTR function appears to decrease innate immune responses, possibly by altering the expression of TLR-4 on airway epithelial cells. This may contribute to chronic bacterial infection of CF airways.

Although some clinicians still believe that cystic fibrosis (CF) lung disease is largely due to hypersecretion of very viscous mucus, it has never been demonstrated that there is mucus hypersecretion in CF and it is clear that there is almost no intact mucin (the principal polymeric component of normal mucus) in CF sputum. CF sputum has lower viscosity when compared to asthma or bronchitis sputa, but is highly tenacious and biochemically most closely resembles pus. Tenacity and lower viscosity lead to decreased cough clearance of infected phlegm, which is thought to induce a persistent inflammatory state in the airway, leading to bronchiectasis. There are many medications and devices either in use or under development that are meant to improve airway hygiene in CF by assisting with sputum expectoration. This paper discusses the scientific basis and potential mechanism of action for many of these interventions and briefly reviews the clinical evidence of their safety and effectiveness.

The 43rd Respiratory Care Journal Conference brought together experts from the United States, Canada, and the United Kingdom to review the art and science of cystic fibrosis (CF). This is the first time that CF was the topic for the Journal Conference, and it came about 6 decades after the disease was named, and 20 years after the gene was discovered on chromosome 7. Though CF is a multisystem disease, it is the chronic and progressive lung disease that causes most of the morbidity and mortality. The participants at the conference reviewed the epidemiology, pathophysiology, treatment, and novel therapies in the pipeline for CF lung disease. They also emphasized the many crucial roles that the respiratory therapist plays in CF, including diagnostic testing, aerosol therapies, airway clearance, infection control, patient and peer education, and patient advocacy. The May and June 2009 issues of the Journal reflect how diligently the participants worked to provide up-to-date reviews and lively discussions of these topics.

Paranasal and sinus disease is present in almost every patient with cystic fibrosis. However, symptoms are rarely reported. Some aspects including polyposis and microbial flora change with patient age. Endoscopy and computerised tomography have broadened our understanding of how this disease affects the sinuses, including an increased recognition of polyposis than previously thought and identification of several disease specific entities such as abnormalities of the lateral nasal wall and uncinate process. Few randomised, controlled trials evaluating medical or surgical treatments of CF sinus disease exist. Sinus surgery may provide some benefit, though there are no established selection criteria for appropriate candidates. A link between sinus disease and lower respiratory tract function may contribute to general health and survival following lung transplantation. Complications of sinonasal disease in CF are rare and include mucoceles and periorbital abscesses.

Background: High-frequency chest wall oscillation (HFCWO) is commonly used by cystic fibrosis (CF) patients for airway clearance. The primary objective of this study was to determine whether the use of a newer HFCWO device that generates oscillations with a triangular waveform results in greater sputum production than a commonly used device that generates oscillations with a sine waveform., Methods: This was a controlled, randomized, double-blind, crossover study. Fifteen clinically stable, adult CF patients participated. Patients performed airway clearance with each device once and at matched oscillation frequencies and pressures. All sputum produced during each session was collected. Patients completed pulmonary function tests before and after each session, and rated the comfort of the two devices., Results: Mean sputum wet and dry weight produced during sine waveform and triangular waveform HFCWO sessions did not differ (p = 0.11 and p = 0.2, respectively). Mean changes in FEV(1) and FVC following HFCWO therapy were also comparable (p = 0.21 and p = 0.56, respectively). However, there was a significant reduction in air trapping by residual volume/total lung capacity ratio following triangular waveform HFCWO (p = 0.01). In addition, in vitro cough transportability was 10.6% greater following therapy with the triangular waveform device (p = 0.05). Patients perceived the two devices as equally comfortable (p = 0.8)., Conclusions: Single-session sputum production is comparable with sine and triangular waveform HFCWO devices. Longer term comparisons are needed to determine whether sustained use of the devices results in clinically important differences in outcomes.

Mucus clearance is the first line of pulmonary defense against inhaled irritants, microorganisms, and allergens. In health, the gel-forming mucins are the principal polymeric components of airway mucus but in cystic fibrosis (CF), the necrotic death of inflammatory and epithelial cells releases a network of copolymerized extracellular DNA and filamentous (F-) actin-producing secretions that are similar to pus and difficult to clear by cilia or airflow. The large amounts of F-actin in CF sputum suggested that thymosin beta4 (Tbeta4) or gelsolin could depolymerize the secondary polymer network of CF sputum. Dose-dependent CF sputum rheology and polymer structure were measured before and after the addition of excipient, dornase alfa, Tbeta4, gelsolin, and Tbeta4 or gelsolin with dornase for 30 min. Sputum was also incubated with Tbeta4 30 microg/mL, gelsolin 10 microg/mL or excipient for 0, 5, 10, 15, 20, or 60 min. There was a dose-dependent decrease in cohesivity with Tbeta4 and a time-dependent decrease in cohesivity at 30 microg/mL. With the combination of dornase alfa and Tbeta4 at 1.5 microg/mL, there was a 65% decrease in elasticity (P = 0.013). There was a time-dependent decrease in cohesivity (P = 0.0004) and elasticity (P = 0.047) with gelsolin and a dose-dependent fall in cohesivity (P = 0.0008). An apparent synergy of Tbeta4 or gelsolin on actin and dornase on DNA may be explained by the combined effect of actin depolymerization and DNA filament severing or by virtue of actin depolymerization increasing the effectiveness of dornase alfa.

People with cystic fibrosis (CF) have chronic airway infection and frequent exposure to antibiotics, which often leads to the emergence of resistant organisms. In addition to the development of multiresistance in common CF pathogens such as Pseudomonas aeruginosa, several newer, inherently resistant gram-negative species are becoming more common, including Burkholderia cepacia complex, Stenotrophomonas maltophilia, Achromobacter (Alcaligenes) xylosoxidans, certain Ralstonia species, and those within the new genus Pandoraea. Many of these are closely related and have similar phenotypes, making accurate laboratory identification challenging. Although their role in contributing to pulmonary disease in CF is not clear, some, such as those of the B. cepacia complex, are clearly linked to an adverse prognosis, and both treatment and infection control issues can pose a real challenge.

Rationale: Cystic fibrosis (CF) is believed to be associated with mucus hypersecretion; thus, the principal airway gel-forming mucins, MUC5AC and MUC5B, are also expected to be increased relative to non-CF secretions. However, we have shown that these mucins are decreased during stable CF disease., Objectives: In this study, we determine if these mucins increase during a pulmonary exacerbation of CF., Methods: Expectorated sputum was collected from 11 adults with CF during stable disease and then during a pulmonary exacerbation and from 12 healthy control subjects. MUC5AC and MUC5B proteins were measured by Western blot. DNA content was measured using microfluorimetry., Results: MUC5AC protein increased by 908% and MUC5B by 59% (p < 0.05 for both) during an exacerbation compared with periods of stable disease. During stable disease, the vol/vol quantity of MUC5AC protein was 89% less than normal mucus, and the mucin-associated sugars, measured using a lectin binding assay, were 46% less compared with normal mucus. The concentration of DNA in CF sputum did not increase during an exacerbation., Conclusions: During a CF exacerbation, concentration of secreted mucin increased to the amount found in mucus from normal subjects, suggesting that the capacity to secrete mucin in response to an infection or inflammatory stimulus is preserved in CF airways. This might help to protect the airway from injury.

The biophysical properties of airway secretions are largely determined by the polymeric components. In normal airway mucus, the gel-forming mucins, MUC5AC and MUC5B, are responsible not only for the viscoelastic properties essential for clearance and protecting the airway epithelium from invaders and water evaporation. With chronic airway infection, inflammatory cell necrosis leads to a predominance of polymeric DNA and F-actin. There is almost no mucin in the sputum of patients with established cystic fibrosis lung disease. Sputum viscoelastic and surface properties determine how well secretions can be cleared by cilia or cough. In this mini-Symposium on Airway Clearance in Cystic Fibrosis, the physiology of CF secretion structure and rheology is discussed in the context of medications and physical maneuvers for enhancing sputum clearance.

Tenacious airway secretions are responsible for much of the lung damage in cystic fibrosis (CF). Label warnings on potential secondary effects of some antihistamines include possible drying or thickening of lower airway secretions, suggesting that they are detrimental to individuals with airway disease. We studied the effects of cyproheptadine hydrochloride (CH) on sputum weight, viscoelasticity, and transportability in CF patients participating in a pilot trial of CH as an appetite stimulant to assure no potential adverse secondary effects on mucus clearance. Sixteen clinically stable subjects were randomized to receive either CH (2 mg QID for 1 week followed by 4 mg QID for 11 weeks) or placebo. Sputum was obtained by voluntary forced cough and expectoration prior to starting CH or placebo and at 4 weeks. Viscoelasticity was measured by rheometry and cough transportability by simulated cough machine. Sufficient paired sputum for rheologic analysis was obtained on four placebo and seven CH subjects and for cough transportability analysis on three placebo and six CH subjects. Weight on all specimens was obtained prior to both analyses. There were no significant differences in sputum weight wet, measures of mucus viscoelasticity (rheology), or cough transportability of mucus between baseline and 4 weeks in patients on placebo or CH. From this limited study, CH, a first-generation antihistamine, appears to have no adverse effects in sputum viscoelasticity or cough transportability in CF patients.

Background: Filamentous actin (F-actin) forms polymers that contribute to the abnormal biophysical properties of sputum. Thymosin beta4 (Tbeta4) is the major monomeric actin-sequestering peptide in cells and can depolymerize F-actin. Tbeta4 could potentially decrease sputum viscoelasticity and adhesivity and improve sputum clearance., Methods: Sputum was collected during pulmonary function testing from 17 subjects during a cystic fibrosis (CF) center visit. Sputum rheology, cough and ciliary transportability, and interfacial tension were measured before and after the addition of dornase alfa at 30 microg/mL; Tbeta4 at 0.3, 3, 30, and 150 microg/mL; and Tbeta4 with dornase alfa at 1.5 microg/mL each. Sputum was separately incubated with Tbeta4 at 30 microg/mL for 0, 10, 20, or 60 min., Results: There was a direct relationship between actin filament length and sputum cohesivity. There was a dose-dependent threshold decrease in cohesivity with Tbeta4 and a time-dependent decrease in cohesivity over 60 min at 30 microg/mL. With the combination of dornase alfa and Tbeta4 at 1.5 microg/mL each, there was a 70% decrease in G*s and a 65% decrease in G' at 1 rad/s (p = 0.013). There was a 44% increase in cough transportability of sputum in vitro (p = 0.037) and a 71% increase in mucociliary transportability of sputum in vitro (p = 0.013) relative to control with the combination of dornase alfa and Tbeta4, but no significant change with dornase alfa or Tbeta4 alone at any concentration., Conclusions: Actin polymer filament length is correlated with sputum cohesivity. Tbeta4 depolymerizes CF sputum actin in both a dose-dependent and a time-dependent manner. An apparent synergy of Tbeta4 on actin and dornase on DNA may be explained by the combined effect of actin depolymerization and DNA filament severing or by virtue of actin depolymerization increasing the effectiveness of dornase alfa.

Background: Polymorphonuclear neutrophil (PMN)-dominated inflammation is prominent in the airways of subjects with cystic fibrosis (CF) and chronic bronchitis (CB). Interleukin (IL)-8, myeloperoxidase (MPO), and DNA are markers of neutrophilic inflammation. We hypothesized that sputum MPO, DNA, and IL-8 concentrations would negatively correlate with pulmonary function and sputum transportability., Methods: We measured pulmonary function and analyzed sputum IL-8, MPO, and DNA concentrations, as well as the transport properties of sputum samples obtained from 16 subjects with CF and 15 subjects with CB. We also evaluated changes in these measurements in paired sputum samples from these subjects obtained 2 to 12 months apart., Results: IL-8 and MPO concentrations in the sputum of CF subjects was inversely correlated with FEV(1) percent predicted (IL-8: r = -0.40; p = 0.003; MPO: r = -0.38; p = 0.003) and FVC percent predicted (IL-8: r = -0.4; p = 0.02; MPO: r = -0.4; p = 0.02). IL-8 and DNA concentrations were inversely correlated with sputum cough transportability (CTR) [IL-8: r = -0.4; p = 0.02; DNA: r = -0.36; p = 0.048]. Changes in DNA concentration in sputum samples from CF subjects over time were inversely correlated with changes in FEV(1) percent predicted (r = -0.58; p = 0.02), FVC percent predicted (r = -0.74; p = 0.002), and CTR (r = -0.59; p = 0.02). There was no correlation among pulmonary function, sputum properties, and inflammatory markers in the sputum from subjects with CB., Conclusions: The sputum concentrations of IL-8, MPO, and DNA appear to be closely associated with pulmonary function in subjects with CF but not in subjects with CB.

Objective: It has been assumed that cystic fibrosis (CF) lung disease is due in part to abnormal airway mucus. Primary ciliary dyskinesia (PCD) is a form of bronchiectasis that is similar to CF in many ways but is caused by congenital defects in mucociliary clearance. Our objective was to compare the biophysical and transport properties of CF and PCD sputa in subjects matched for age and degree of lung function impairment., Design, Setting, Participants: PCD patients (n = 19; mean age, 9.5 +/- 3.0 years [+/- SD]; FEV1, 65.0 +/- 7.8 L) were recruited from the clinic at the Royal Brompton Hospital. Patients with CF (n = 30, mean age, 10.8 +/- 2.6 years; FEV1, 61.8 +/- 22.8 L) were identified from the Wake Forest University School of Medicine CF Center. Pulmonary function testing and sputum collection were performed as part of routine, scheduled clinic visits., Measurements: Pulmonary function was measured by spirometry, and sputum was collected during the pulmonary function test maneuver. Some patients were longitudinally assessed at visits during the course of 3 years. Sputum properties measured were dynamic viscoelasticity, wettability, cohesivity, interfacial (surface) tension, solids composition, DNA and interleukin (IL)-8 concentration, in vitro mucociliary transportability, and cough transportability., Results: Inflammation as measured by IL-8 concentration was three times greater in the PCD sputa (p < 0.0001). There were no significant differences in the sputum biophysical or transport properties comparing CF with PCD sputum., Conclusions: It is unlikely that established CF lung disease is principally due to abnormal sputum properties, and it is more likely that the biophysical and transport properties reflect disease severity regardless of whether bronchiectasis is due to CF or PCD.

Although aerosol therapy is most commonly used to treat asthma and COPD, there are a large number of aerosol medications now used or in development for other diseases. Mucoactive agents have long been available by aerosol, but now we have truly effective drugs to improve effective airway clearance including dornase alfa, hyperosmolar saline, and aerosol surfactant. Inhaled antibiotics are available for the treatment of cystic fibrosis, bronchiectasis and other chronic airway infections. With the development of devices that can target aerosol to the deep lung, the opportunity to deliver medications systemically by the aerosol route has become a reality. Insulin, recently approved in the US as aerosol therapy, and other peptides are systemically absorbed from the distal airway and alveolus. Aerosol gene transfer therapy to correct abnormalities associated with cystic fibrosis, primary ciliary dyskinesia and other airway diseases also holds great potential.

The quantitative analysis of a polymer network is important for understanding its role in biological function. We developed a Matlab program to recognize and segment filaments in a 2-D image, and measure and describe the structure. Our algorithm improved the speed of the Lichtenstein Fiberscore segmentation algorithm by using matrix convolutions, compared filament length by the algorithms of Kulpa, Lichtenstein, and Kimura, and measured the number of branchpoints and Euler number. A user interface was added to easily manipulate algorithm parameters, select images, and visualize results. We used the program to compare the DNA biopolymer network of cystic fibrosis (CF) sputum with mucus from patients without respiratory problems. We also examined an image of fibrin. The images were taken with a laser scanning confocal microscope after staining the specimens with Yo-Yo-1. Computation using matrix convolutions reduced the execution time (Pentium III) of a 512 x 512 TIF image from 18 min to 15s. The Kimura length estimation appeared best at describing filament length because it varied least with filament orientation. The image of CF sputum showed increased filament length, more branchpoints, and more negative Euler number compared to the normal sample. These quantitative descriptions of the network can be correlated to material, mechanical, diffusion, or flow properties, physiological processes, or therapy.

Fourteen- and 15-member macrolide antibiotics are under investigation as potential therapeutic agents for cystic fibrosis (CF). The nonantibiotic mechanisms of action of these compounds in CF are not understood. We used nasal potential difference (NPD) measurements to test the effect of macrolides on airway epithelial ion (chloride, sodium) transport of CF mice and humans. We tested clarithromycin and azithromycin in mice, and clarithromycin in patients with CF. Baseline and post-treatment NPD was measured in two strains (C57Bl6 and BalbC) of CF transmembrane regulator "knockout" and littermate control mice, and in DeltaF508/DeltaF508 mice. In addition, NPD was measured in 18 human subjects with CF (17 DeltaF-508/DeltaF-508 and 1 DeltaF-508/other) who were undergoing a 12-month, randomized, double-blind crossover study of the effects of clarithromycin on pulmonary outcome in CF. Neither clarithromycin nor azithromycin affected ion transport characteristics of normal or CF nasal epithelium in either mouse or humans. We conclude that the apparent beneficial effects of macrolides on pulmonary outcome in CF are not mediated by their modulation of ion transport.

Cystic fibrosis (CF) is characterized by progressive airway obstruction. Although it has been postulated that this is due in part to mucus hypersecretion, there are no published data showing an increase in the gel-forming mucins MUC5AC or MUC5B in CF secretions. We used confocal microscopy to assess the amount of mucin-like glycoprotein and DNA in CF sputum and found more mucin in bronchitis sputum and a much greater amount of DNA in CF sputum. We then used antibodies to MUC5AC and MUC5B with Western gels and dot-blot to quantify mucin in sputum from 12 patients with CF and 11 subjects without lung disease. There was a 70% decrease in MUC5B and a 93% decrease in MUC5AC in CF sputum (P < 0.005 for both). We conclude that the vol/vol concentration of MUC5AC and MUC5B are decreased in the CF airways relative to normal mucus. This may be due to a relative increase in other components of sputum in the CF airway or to a primary defect in mucin secretion in CF.

The use of troleandomycin as adjunctive therapy for the treatment of patients with corticosteroid-dependent asthma first suggested an immunomodulatory effect of the macrolide antibiotics. This led to studies of the macrolides in other chronic airway diseases, such as diffuse panbronchiolitis (DPB), a disease occurring primarily in East Asia. The use of macrolides for the therapy of patients with DPB has led to dramatic improvements in pulmonary function and prolonged survival. Similar benefits have been documented in Japanese studies of bronchiectasis, chronic bronchitis, and sinobronchial syndrome. Clinical and pathologic similarities between DPB and cystic fibrosis (CF) led to the investigation of macrolides for the treatment of CF. Data now suggest that persons with CF will benefit from macrolide therapy. In vitro and in vivo studies suggest that macrolides may inhibit the pulmonary influx of neutrophils, inhibit the release of proinflammatory cytokines, protect the epithelium from bioactive phospholipids, and improve the transportability of airway secretions. The immunomodulatory effects of the macrolides also may be beneficial for the treatment of other chronic inflammatory conditions.

We describe a 20-year-old patient with cystic fibrosis who developed acute nonoliguric renal failure associated with inhaled tobramycin. Clinical evaluation and renal biopsy findings were consistent with aminoglycoside-induced changes. Renal failure due to inhaled aminoglycosides has not been previously reported. The incidence may rise, however, with the increased use of this treatment modality. Measurable tobramycin levels due to inhalational therapy with conventional dosing in the reported patient indicate that the drug can be systemically absorbed, and renal tubular toxicity may occur., (Copyright 2002 Wiley-Liss, Inc.)

Neutrophil-dominated inflammation is prominent in the cystic fibrosis (CF) and chronic bronchitis (CB) airways. We assessed the degree of airway inflammation by measuring the sputum concentrations of interleukin (IL)-8, myeloperoxidase (MPO), and deoxyribonucleic acid (DNA). We determined the relationship among the concentrations of these mediators and investigated methodological problems that may be responsible for reported variability in measurements. Sputa obtained from 31 patients were solubilized with phosphate-buffered saline, dithiothreitol (DTT) (0.1% or 1%), or dornase alfa (0.2 mg/mL). The sputum concentration of IL-8 and MPO was measured by enzyme-linked immunosorbent assay (ELISA), and DNA was measured using microfluorimetry. There was a significant relationship among sputum IL-8, MPO, and DNA. For MPO (means +/- SD), CF was 1,392 +/- 771 vs. CB at 75 +/- 65 mcg/mL; P < 0.0001. For IL-8: CF was 239 +/- 154 vs. CB at 121 +/- 108 ng/mL; P = 0.0002. For DNA, CF was 1.707 +/- 1.25 vs. CB at 0.184 +/- 0.272 mg/mL; P < 0.0001. The MPO concentration in CF sputum was approximately double after in vitro treatment with dornase alfa (P < 0.0001). There is a greater concentration of IL-8, MPO, and DNA in CF than in CB sputa. There is a significant relationship among these inflammatory markers in sputum. DNA polymers bind myeloperoxidase in the sputum, and we speculate that treatment with dornase alfa may remove a source of MPO inhibition., (Copyright 2001 Wiley-Liss, Inc.)

Although the activity of nitric oxide (NO) synthases are increased in lung tissue of patients with cystic fibrosis, the concentrations of nasal and exhaled NO have recently been found to be decreased in cystic fibrosis. This could either be due to reduced NO formation or metabolism of NO within airway fluids. In this study, the stable NO metabolites, nitrate and nitrite, were determined in the saliva and sputum of 18 stable cystic fibrosis patients, 21 cystic fibrosis patients during a pulmonary exacerbation, and in saliva and endotracheal secretions of normal controls. Median saliva concentrations of NO metabolites (nitrate plus nitrite) were 704 mumol/l (95% confidence interval (CI) 419 to 1477) in stable cystic fibrosis patients, 629 mumol/l (95% CI 382 to 1392) in cystic fibrosis patients presenting with pulmonary exacerbation, and 313 mumol/l (95% CI 312 to 454) in controls. Median sputum NO metabolite concentration in stable cystic fibrosis was 346 mumol/l (95% CI 311 to 504). This was not significantly different from cystic fibrosis patients presenting with pulmonary exacerbation (median 184 mumol/l, 95% CI 249 to 572), but significantly higher than in endotracheal secretions of controls (median 144 mumol/l, 95% CI 96 to 260). Sputum NO metabolite concentration in cystic fibrosis pulmonary exacerbation significantly increased during antibiotic treatment. A positive correlation was observed between sputum NO metabolites and lung function in stable cystic fibrosis, suggesting less airway NO formation in cystic fibrosis patients with more severe lung disease. These data indicate that decreased exhaled NO concentrations in cystic fibrosis patients may be due to retention and metabolism of NO within the airway secretions. However, sputum NO metabolites are not a useful marker of airway inflammation in cystic fibrosis lung disease.

Poor sputum clearance has been related to sputum adhesion tension. In this study, we describe a modified du Noüy ring method for measuring the surface tension (gamma) of small samples of sputum and for comparinge the calculated work of adhesion (Wad) for sputum specimens with the measured mucociliary transportability (MCTR) and cough transportability (CTR). The gamma, as measured by this method, correlates with gamma measured by sputum contact angle on a low-surface-energy solid (R2 = 0.368, P = 0.03). There is a small but significant difference in measurements made by these two methods (P = 0.03). Wad calculated from the surface tension ring method is inversely correlated with CTR (R2 = 0.181, P = 0.004) but has no correlation with MCTR in this study. The miniaturized ring method gives accurate and reproducible measurements of the surface tension of small amounts of respiratory secretions. Because sputum behaves enough like a liquid that the assumptions made in using the Young equation to calculate Wad appear valid, we also showed that the Neumann equation can be used to determine the surface tension of sputum by its contact angle on tetrafluoroethylene (Teflon).