Randomized, double-blind, placebo-controlled, dose-escalating study of aerosolized interferon gamma-1b in patients with mild to moderate cystic fibrosis lung disease

Nebuliser systems for drug delivery in cystic fibrosis

BACKGROUND

Nebuliser systems are used to deliver medications to the lungs, to control the symptoms and the progression of lung disease in people with cystic fibrosis (CF). There are many different nebulised-medications prescribed for people with CF and there are many different types of nebuliser systems. Some of these nebulised medications are licenced for, and can be taken via only one type of nebuliser system; some are licensed for, and can be taken via more than one type of nebuliser system. This is an update to a previous systematic review.

OBJECTIVES

To assess the time efficiency, effectiveness, safety, cost and impact of use (e.g. burden of care, adherence, quality of life (QoL)) of different nebuliser systems, when used with different inhaled medications for people with CF.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches, handsearching of relevant journals and abstract books containing conference proceedings. We searched the reference lists of each study for additional publications and approached the manufacturers of both nebuliser systems and nebulised medications for published and unpublished data. We also searched online trial registries. Date of the most recent search: 9 August 2023.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs comparing nebuliser systems, including conventional nebulisers, vibrating mesh technology (VMT) systems, adaptive aerosol delivery (AAD) systems and ultrasonic nebuliser systems.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion. They also independently extracted data and assessed the risk of bias. A third review author assessed studies where agreement could not be reached. They assessed the certainty of the evidence using GRADE.

MAIN RESULTS

The search identified 216 studies with 33 of these (2270 participants) included in the review. These studies compared the delivery of tobramycin, colistin, dornase alfa, hypertonic saline and other solutions through the different nebuliser systems in children and adults with CF. This review demonstrates variability in the delivery of medication depending on the nebuliser system used. The certainty of the evidence ranged from low to very low. Some conventional nebuliser systems providing higher flows, higher respirable fractions, and smaller particles decrease treatment time, increase deposition (the amount of drug reaching the lung), and may be preferred by people with CF, as compared to other conventional nebuliser systems providing lower flows, lower respirable fractions and larger particles. Newer nebuliser systems using AAD, or VMT (or both) reduce treatment time compared to conventional systems. Deposition (as a percentage of priming dose) with AAD is greater than with conventional systems. VMT systems may give greater deposition than conventional systems when measuring sputum levels. The available data indicate that these newer systems are safe when used with an appropriate priming dose, which may be different to the priming dose used for conventional systems. There is an indication that adherence is maintained or improved and that individuals prefer AAD or VMT systems, but also that some nebuliser systems using VMT may be subject to increased system failures. There is limited, unclear evidence on the impact of different nebuliser systems on lung function and a lack of data on the impact of different nebuliser systems on our outcomes of quality of life (QoL), adverse effects, respiratory exacerbations and related implications, adherence, satisfaction, cost and device reliability.

AUTHORS' CONCLUSIONS

Newer technologies e.g. AAD and VMT have advantages over conventional systems in terms of treatment time, deposition as a percentage of priming dose, preference and adherence. Data are lacking for all varieties of medications which are used in CF care, including different inhaled antibiotics or hypertonic saline, with all delivery (nebuliser system) possibilities. Long-term RCTs are needed to evaluate different nebuliser systems to determine patient-focused outcomes (such as QoL and burden of care), safe and effective dosing levels of a wide variety of medications, clinical outcomes (such as hospitalisations and need for antibiotics), and an economic evaluation of their use. There are insufficient data to establish whether one nebuliser system is better than another overall. Clinicians should be aware of the variability in the performance of different nebuliser systems, compatibility with specific nebulised medication, and they must work with their patients to choose the best nebuliser system for each individual. This is likely to be an ongoing process as the needs and circumstances of each individual change over time.

Immune Response to Biofilm Growing Pulmonary Pseudomonas aeruginosa Infection

Biofilm infections are tolerant to the host responses and recalcitrance to antibiotic drugs and disinfectants. The induced host-specific innate and adaptive immune responses by established biofilms are significantly implicated and contributes to the course of the infections. Essentially, the host response may be the single one factor impacting the outcome most, especially in cases where the biofilm is caused by low virulent opportunistic bacterial species. Due to the chronicity of biofilm infections, activation of the adaptive immune response mechanisms is frequently experienced, and instead of clearing the infection, the adaptive response adds to the pathogenesis. To a high degree, this has been reported for chronic Pseudomonas aeruginosa lung infections, where both a pronounced antibody response and a skewed Th1/Th2 balance has been related to a poorer outcome. In addition, detection of an adaptive immune response can be used as a significant indicator of a chronic P. aeruginosa lung infection and is included in the clinical definitions as such. Those issues are presented in the present review, along with a characterization of the airway structure in relation to immune responses towards P. aeruginosa pulmonary infections.

Cystic Fibrosis Lung Disease in the Aging Population

The demographics of the population with cystic fibrosis (CF) is continuously changing, with nowadays adults outnumbering children and a median predicted survival of over 40 years. This leads to the challenge of treating an aging CF population, while previous research has largely focused on pediatric and adolescent patients. Chronic inflammation is not only a hallmark of CF lung disease, but also of the aging process. However, very little is known about the effects of an accelerated aging pathology in CF lungs. Several chronic lung disease pathologies show signs of chronic inflammation with accelerated aging, also termed “inflammaging”; the most notable being chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF). In these disease entities, accelerated aging has been implicated in the pathogenesis via interference with tissue repair mechanisms, alterations of the immune system leading to impaired defense against pulmonary infections and induction of a chronic pro-inflammatory state. In addition, CF lungs have been shown to exhibit increased expression of senescence markers. Sustained airway inflammation also leads to the degradation and increased turnover of cystic fibrosis transmembrane regulator (CFTR). This further reduces CFTR function and may prevent the novel CFTR modulator therapies from developing their full efficacy. Therefore, novel therapies targeting aging processes in CF lungs could be promising. This review summarizes the current research on CF in an aging population focusing on accelerated aging in the context of chronic airway inflammation and therapy implications.

Airway Redox Homeostasis and Inflammation Gone Awry: From Molecular Pathogenesis to Emerging Therapeutics in Respiratory Pathology

As aerobic organisms, we are continuously and throughout our lifetime subjected to an oxidizing atmosphere and, most often, to environmental threats. The lung is the internal organ most highly exposed to this milieu. Therefore, it has evolved to confront both oxidative stress induced by reactive oxygen species (ROS) and a variety of pollutants, pathogens, and allergens that promote inflammation and can harm the airways to different degrees. Indeed, an excess of ROS, generated intrinsically or from external sources, can imprint direct damage to key structural cell components (nucleic acids, sugars, lipids, and proteins) and indirectly perturb ROS-mediated signaling in lung epithelia, impairing its homeostasis. These early events complemented with efficient recognition of pathogen- or damage-associated recognition patterns by the airway resident cells alert the immune system, which mounts an inflammatory response to remove the hazards, including collateral dead cells and cellular debris, in an attempt to return to homeostatic conditions. Thus, any major or chronic dysregulation of the redox balance, the air-liquid interface, or defects in epithelial proteins impairing mucociliary clearance or other defense systems may lead to airway damage. Here, we review our understanding of the key role of oxidative stress and inflammation in respiratory pathology, and extensively report current and future trends in antioxidant and anti-inflammatory treatments focusing on the following major acute and chronic lung diseases: acute lung injury/respiratory distress syndrome, asthma, chronic obstructive pulmonary disease, pulmonary fibrosis, and cystic fibrosis.

Volatile molecules for COVID-19: A possible pharmacological strategy?

COVID-19 is a novel coronavirus disease with a higher incidence of bilateral pneumonia and pleural effusion. The high pulmonary tropism and contagiousness of the virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), have stimulated new approaches to combat its widespread diffusion. In developing new pharmacological strategies, the chemical characteristic of volatility can add therapeutic value to the hypothetical drug candidate. Volatile molecules are characterized by a high vapor pressure and are consequently easily exhaled by the lungs after ingestion. This feature could be exploited from a pharmacological point of view, reaching the site of action in an uncommon way but allowing for drug delivery. In this way, a hypothetical molecule for COVID-19 should have a balance between its lung exhalation characteristics and both antiviral and anti-inflammatory pharmacological action. Here, the feasibility, advantages, and disadvantages of a therapy based on oral administration of possible volatile drugs for COVID-19 will be discussed. Both aerosolized antiviral therapy and oral intake of volatile molecules are briefly reviewed, and an evaluation of 1,8-cineole is provided in view of a possible clinical use and also for asymptomatic COVID-19.

Developing Novel Host-Based Therapies Targeting Microbicidal Responses in Macrophages and Neutrophils to Combat Bacterial Antimicrobial Resistance

Antimicrobial therapy has provided the main component of chemotherapy against bacterial pathogens. The effectiveness of this strategy has, however, been increasingly challenged by the emergence of antimicrobial resistance which now threatens the sustained utility of this approach. Humans and animals are constantly exposed to bacteria and have developed effective strategies to control pathogens involving innate and adaptive immune responses. Impaired pathogen handling by the innate immune system is a key determinant of susceptibility to bacterial infection. However, the essential components of this response, specifically those which are amenable to re-calibration to improve host defense, remain elusive despite extensive research. We provide a mini-review focusing on therapeutic targeting of microbicidal responses in macrophages and neutrophils to de-stress reliance on antimicrobial therapy. We highlight pre-clinical and clinical data pointing toward potential targets and therapies. We suggest that developing focused host-directed therapeutic strategies to enhance "pauci-inflammatory" microbial killing in myeloid phagocytes that maximizes pathogen clearance while minimizing the harmful consequences of the inflammatory response merits particular attention. We also suggest the importance of One Health approaches in developing host-based approaches through model development and comparative medicine in informing our understanding of how to deliver this strategy.

Ivacaftor decreases monocyte sensitivity to interferon-γ in people with cystic fibrosis

This study demonstrates that initiation of the CFTR modulator ivacaftor in people with cystic fibrosis and susceptible CFTR mutations causes an acute reduction in blood monocyte sensitivity to the key proinflammatory cytokine IFN-γ http://bit.ly/2TeI6LG.

Effective nebulization of interferon-γ using a novel vibrating mesh

BACKGROUND

Interferon gamma (IFN-γ) is a clinically relevant immunomodulatory cytokine that has demonstrated significant potential in the treatment and management of respiratory diseases such as tuberculosis and pulmonary fibrosis. As with all large biomolecules, clinical translation is dependent on effective delivery to the disease site and delivery of IFN-γ as an aerosol offers a logical means of drug targeting. Effective localization is often hampered by instability and a lack of safe and efficient delivery systems. The present study sought to determine how effectively IFN-γ can be nebulized using two types of vibrating mesh nebulizer, each with differing mesh architectures, and to investigate the comparative efficiency of delivery of therapeutically active IFN-γ to the lungs.

METHODS

Nebulization of IFN-γ was carried out using two different Aerogen vibrating mesh technologies with differing mesh architectures. These technologies represent both a standard commercially available mesh type (Aerogen Solo®) and a new iteration mesh (Photo-defined aperture plate (PDAP®). Extensive aerosol studies (aerosol output and droplet analysis, non-invasive and invasive aerosol therapy) were conducted in line with regulatory requirements and characterization of the stability and bioactivity of the IFN-γ post-nebulization was confirmed using SDS-PAGE and stimulation of Human C-X-C motif chemokine 10 (CXCL 10) also known as IFN-γ-induced protein 10KDa (IP 10) expression from THP-1 derived macrophages (THP-1 cells).

RESULTS

Aerosol characterization studies indicated that a significant and reproducible dose of aerosolized IFN-γ can be delivered using both vibrating mesh technologies. Nebulization using both devices resulted in an emitted dose of at least 93% (100% dose minus residual volume) for IFN-γ. Characterization of aerosolized IFN-γ indicated that the PDAP was capable of generating droplets with a significantly lower mass median aerodynamic diameter (MMAD) with values of 2.79 ± 0.29 μm and 4.39 ± 0.25 μm for the PDAP and Solo respectively. The volume median diameters (VMD) of aerosolized IFN-γ corroborated this with VMDs of 2.33 ± 0.02 μm for the PDAP and 4.30 ± 0.02 μm for the Solo. SDS-PAGE gels indicated that IFN-γ remains stable after nebulization by both devices and this was confirmed by bioactivity studies using a THP-1 cell model in which an alveolar macrophage response to IFN-γ was determined. IFN-γ nebulized by the PDAP and Solo devices had no significant effect on the key inflammatory biomarker cytokine IP-10 release from this model in comparison to non-nebulized controls. Here we demonstrate that it is possible to combine IFN-γ with vibrating mesh nebulizer devices and facilitate effective aerosolisation with minimal impact on IFN-γ structure or bioactivity.

CONCLUSIONS

It is possible to nebulize IFN-γ effectively with vibrating mesh nebulizer devices without compromising its stability. The PDAP allows for generation of IFN-γ aerosols with improved aerodynamic properties thereby increasing its potential efficiency for lower respiratory tract deposition over current technology, whilst maintaining the integrity and bioactivity of IFN-γ. This delivery modality therefore offers a rational means of facilitating the clinical translation of inhaled IFN-γ.

A specialized method of sputum collection and processing for therapeutic interventions in cystic fibrosis

Cystic fibrosis (CF) lung disease is characterized by aggressive neutrophil-dominated inflammation mediated in large part by neutrophil elastase (NE), an omnivorous protease released by activated or disintegrating neutrophils and a key therapeutic target. To date, several short-term studies have shown that anti-NE compounds can inhibit NE and have anti-inflammatory effects. However, progression to large-scale or multicenter clinical trials has been hampered by the fact that the current gold standard methodology of evaluating airway NE inhibition, bronchoalveolar lavage (BAL), is invasive, difficult to standardize across sites and excludes those with severe lung disease. Attempts to utilize sputum that is either spontaneously expectorated (SS) or induced (IS) have been hindered by poor reproducibility, often due to the various processing methods employed. In this study, we evaluate TEmperature-controlled Two-step Rapid Isolation of Sputum (TETRIS), a specialized method for the acquisition and processing of SS and IS. Using TETRIS, we show for the first time that NE activity and cytokine levels are comparable in BAL, SS and IS samples taken from the same people with CF (PWCF) on the same day once this protocol is used. We correlate biomarkers in TETRIS-processed IS and clinical outcome measures including FEV₁, and show stability and reproducible inhibition of NE over time in IS processed by TETRIS. The data offer a tremendous opportunity to evaluate prognosis and therapeutic interventions in CF and to study the full spectrum of people with PWCF, many of whom have been excluded from previous studies due to being unfit for BAL or unable to expectorate sputum.

Chemoattractants and cytokines in primary ciliary dyskinesia and cystic fibrosis: key players in chronic respiratory diseases

Patients with primary ciliary dyskinesia (PCD) and cystic fibrosis (CF), two inherited disorders, suffer from recurrent airway infections characterized by persistent bacterial colonization and uncontrollable inflammation. Although present in high counts, neutrophils fail to clear infection in the airways. High levels of C-X-C motif chemokine ligand 8/interleukin-8 (CXCL8/IL-8), the most potent chemokine to attract neutrophils to sites of infection, are detected in the sputum of both patient groups and might cause the high neutrophil influx in the airways. Furthermore, in CF, airway neutrophils are highly activated because of the genetic defect and the high levels of proinflammatory chemoattractants and cytokines (e.g., CXCL8/IL-8, tumor necrosis factor-α and IL-17). The overactive state of neutrophils leads to lung damage and fuels the vicious circle of infection, excessive inflammation and tissue damage. The inflammatory process in CF airways is well characterized, whereas the lung pathology in PCD is far less studied. The knowledge of CF lung pathology could be useful to guide molecular investigations of the inflammatory processes in PCD lungs. Current available therapies can not completely remedy the chronic airway infections in these diseases. This review gives an overview of the role that chemoattractants and cytokines play in these neutrophil-dominated lung pathologies. Finally, the most frequently applied treatments in CF and PCD and new experimental therapies to reduce neutrophil-dominated airway inflammation are described.

Drugs and Targets in Fibrosis

Fibrosis contributes to the development of many diseases and many target molecules are involved in fibrosis. Currently, the majority of fibrosis treatment strategies are limited to specific diseases or organs. However, accumulating evidence demonstrates great similarities among fibroproliferative diseases, and more and more drugs are proved to be effective anti-fibrotic therapies across different diseases and organs. Here we comprehensively review the current knowledge on the pathological mechanisms of fibrosis, and divide factors mediating fibrosis progression into extracellular and intracellular groups. Furthermore, we systematically summarize both single and multiple component drugs that target fibrosis. Future directions of fibrosis drug discovery are also proposed.

Strategies for the etiological therapy of cystic fibrosis

Etiological therapies aim at repairing the underlying cause of cystic fibrosis (CF), which is the functional defect of the cystic fibrosis transmembrane conductance regulator (CFTR) protein owing to mutations in the CFTR gene. Among these, the F508del CFTR mutation accounts for more than two thirds of CF cases worldwide. Two somehow antinomic schools of thought conceive CFTR repair in a different manner. According to one vision, drugs should directly target the mutated CFTR protein to increase its plasma membrane expression (correctors) or improve its ion transport function (potentiators). An alternative strategy consists in modulating the cellular environment and proteostasis networks in which the mutated CFTR protein is synthesized, traffics to its final destination, the plasma membrane, and is turned over. We will analyze distinctive advantages and drawbacks of these strategies in terms of their scientific and clinical dimensions, and we will propose a global strategy for CF research and development based on a reconciliatory approach. Moreover, we will discuss the utility of preclinical biomarkers that may guide the personalized, patient-specific implementation of CF therapies.

Innate and Adaptive Immunity in Cystic Fibrosis

Cystic fibrosis (CF) lung disease is characterized by persistent and unresolved inflammation, with elevated proinflammatory and decreased anti-inflammatory cytokines, and greater numbers of immune cells. Hyperinflammation is recognized as a leading cause of lung tissue destruction in CF. Hyper-inflammation is not solely observed in the lungs of CF patients, since it may contribute to destruction of exocrine pancreas and, likely, to defects in gastrointestinal tract tissue integrity. Paradoxically, despite the robust inflammatory response, and elevated number of immune cells (such as neutrophils and macrophages), CF lungs fail to clear bacteria and are more susceptible to infections. Here, we have summarized the current understanding of immune dysregulation in CF, which may drive hyperinflammation and impaired host defense.

Use of ibuprofen to assess inflammatory biomarkers in induced sputum: Implications for clinical trials in cystic fibrosis

BACKGROUND

High-dose ibuprofen (HDI) is a clinically beneficial anti-inflammatory regimen that may be a useful reagent to study induced sputum inflammatory marker changes over short study periods appropriate for early-phase CF clinical trials.

METHODS

We conducted a 28-day, open-label, randomized, controlled trial among 72 clinically stable CF subjects (FEV1≥40% predicted) randomized to HDI or routine care that assessed IL-6, IL-8, TNF-α, IL-1-β, free neutrophil elastase, and white cell counts with differentials change from baseline in induced sputum.

RESULTS

IL-6 was the only biomarker with significant within-group change: 0.13 log10 pg/mL mean reduction among ibuprofen-treated subjects (p=0.04); and no change in the control group. IL-6 change between groups was statistically significant (p=0.024). No other inflammatory biomarker differences were observed between groups after 28 days.

CONCLUSION

Although we studied only one agent, HDI, these results suggest that one month may be inadequate to assess anti-inflammatory candidates using markers from induced sputum.

Inflammation in cystic fibrosis lung disease: Pathogenesis and therapy

Lung disease is the major cause of morbidity and mortality in patients with cystic fibrosis (CF). Although CF lung disease is primarily an infectious disorder, the associated inflammation is both intense and ineffective at clearing pathogens. Persistent high-intensity inflammation leads to permanent structural damage of the CF airways and impaired lung function that eventually results in respiratory failure and death. Several defective inflammatory responses have been linked to cystic fibrosis transmembrane conductance regulator (CFTR) deficiency including innate and acquired immunity dysregulation, cell membrane lipid abnormalities, various transcription factor signaling defects, as well as altered kinase and toll-like receptor responses. The inflammation of the CF lung is dominated by neutrophils that release oxidants and proteases, particularly elastase. Neutrophil elastase in the CF airway secretions precedes the appearance of bronchiectasis, and correlates with lung function deterioration and respiratory exacerbations. Anti-inflammatory therapies are therefore of particular interest for CF lung disease but must be carefully studied to avoid suppressing critical elements of the inflammatory response and thus worsening infection. This review examines the role of inflammation in the pathogenesis of CF lung disease, summarizes the results of past clinical trials and explores promising new anti-inflammatory options.

Risk of hemoptysis in cystic fibrosis clinical trials: A retrospective cohort study

BACKGROUND

Cystic fibrosis (CF) is characterized by airway infection and inflammation resulting in respiratory complications including hemoptysis. The objectives of this study were to characterize the risk of hemoptysis attributable to underlying disease and in the presence of standard of care therapy.

METHODS

This retrospective cohort study estimated hemoptysis rates overall and by relevant risk factors utilizing adverse event data from longitudinal prospective CF clinical trials.

RESULTS

Of the 1008 participants, 73% were ≤18 years old; of 929 with available spirometry, 27% had an FEV1<70% predicted. During the average 8.2 months of follow-up, 8% experienced ≥1 hemoptysis events (95% CI: 6%, 10%). Of the 125 events, 76% were mild in severity and only 9% were serious. Hemoptysis rates were greater among adults than children, those with FEV1<70% predicted, and participants infected with P. aeruginosa but not with S. aureus.

CONCLUSIONS

Hemoptysis is a common adverse event among CF clinical trial participants, and particularly in adults with more severe lung disease. These results can be used to predict event occurrence in future clinical trials.

Clinical implications of interferon-γ genetic and epigenetic variants

Interferon-γ (IFN-γ) is an integral and critical molecule of the immune system, with multiple functions, mostly related to the T helper type 1 (Th1) response to infection. It is critical for defence against mycobacterial infection and is of increasing interest in defence against fungi. In this article, we review the genetic and epigenetic variants affecting IFN-γ expression and investigate its role in disease, with an emphasis on fungal diseases such as invasive and chronic pulmonary aspergillosis. Over 347 IFN-γ gene variants have been described, in multiple ethnic populations. Many appear to confer a susceptibility to disease, especially tuberculosis (TB) and hepatitis, but also some non-infectious conditions such as aplastic anaemia, cervical cancer and psoriasis. Several epigenetic modifications are also described, increasing IFN-γ expression in Th1 lymphocytes and reducing IFN-γ expression in Th2 lymphocytes. Recombinant IFN-γ administration is licensed for the prophylaxis of infection (bacterial and fungal) in patients with the phagocyte functional deficiency syndrome chronic granulomatous disease, although the benefits appear limited. Interferon-γ therapy is given to patients with profound defects in IFN-γ and interleukin-12 production and appears to be beneficial for patients with invasive aspergillosis and cryptococcal meningitis, but the studies are not definitive. A high proportion of patients with chronic pulmonary aspergillosis are poor producers of IFN-γ in response to multiple stimuli and could also benefit from IFN-γ administration. The investigation and management of patients with possible or demonstrated IFN-γ deficiency in adulthood is poorly studied and could be greatly enhanced with the integration of genetic data.

In vivo evaluation of adeno-associated virus gene transfer in airways of mice with acute or chronic respiratory infection

Patients with cystic fibrosis (CF) often suffer chronic lung infection with concomitant inflammation, a setting that may reduce the efficacy of gene transfer. While gene therapy development for CF often involves viral-based vectors, little is known about gene transfer in the context of an infected airway. In this study, three mouse models were established to evaluate adeno-associated virus (AAV) gene transfer in such an environment. Bordetella bronchiseptica RB50 was used in a chronic, nonlethal respiratory infection in C57BL/6 mice. An inoculum of ∼10(5) CFU allowed B. bronchiseptica RB50 to persist in the upper and lower respiratory tracts for at least 21 days. In this infection model, administration of an AAV vector on day 2 resulted in 2.8-fold reduction of reporter gene expression compared with that observed in uninfected controls. Postponement of AAV administration to day 14 resulted in an even greater (eightfold) reduction of reporter gene expression, when compared with uninfected controls. In another infection model, Pseudomonas aeruginosa PAO1 was used to infect surfactant protein D (SP-D) or surfactant protein A (SP-A) knockout (KO) mice. With an inoculum of ∼10(5) CFU, infection persisted for 2 days in the nasal cavity of either mouse model. Reporter gene expression was approximately ∼2.5-fold lower compared with uninfected mice. In the SP-D KO model, postponement of AAV administration to day 9 postinfection resulted in only a two fold reduction in reporter gene expression, when compared with expression seen in uninfected controls. These results confirm that respiratory infections, both ongoing and recently resolved, decrease the efficacy of AAV-mediated gene transfer.

IFN-γ stimulates autophagy-mediated clearance of Burkholderia cenocepacia in human cystic fibrosis macrophages

Burkholderia cenocepacia is a virulent pathogen that causes significant morbidity and mortality in patients with cystic fibrosis (CF), survives intracellularly in macrophages, and uniquely causes systemic infections in CF. Autophagy is a physiologic process that involves engulfing non-functional organelles and proteins and delivering them for lysosomal degradation, but also plays a role in eliminating intracellular pathogens, including B. cenocepacia. Autophagy is defective in CF but can be stimulated in murine CF models leading to increased clearance of B. cenocepacia, but little is known about autophagy stimulation in human CF macrophages. IFN-γ activates macrophages and increases antigen presentation while also inducing autophagy in macrophages. We therefore, hypothesized that treatment with IFN-γ would increase autophagy and macrophage activation in patients with CF. Peripheral blood monocyte derived macrophages (MDMs) were obtained from CF and non-CF donors and subsequently infected with B. cenocepacia. Basal serum levels of IFN-γ were similar between CF and non-CF patients, however after B. cenocepacia infection there is deficient IFN-γ production in CF MDMs. IFN-γ treated CF MDMs demonstrate increased co-localization with the autophagy molecule p62, increased autophagosome formation, and increased trafficking to lysosomes compared to untreated CF MDMs. Electron microscopy confirmed IFN-γ promotes double membrane vacuole formation around bacteria in CF MDMs, while only single membrane vacuoles form in untreated CF cells. Bacterial burden is significantly reduced in autophagy stimulated CF MDMs, comparable to non-CF levels. IL-1β production is decreased in CF MDMs after IFN-γ treatment. Together, these results demonstrate that IFN-γ promotes autophagy-mediated clearance of B. cenocepacia in human CF macrophages.

IFN-γ-mediated reduction of large-conductance, Ca2+-activated, voltage-dependent K+ (BK) channel activity in airway epithelial cells leads to mucociliary dysfunction

Effective mucociliary clearance (MCC) depends in part on adequate airway surface liquid (ASL) volume to maintain an appropriate periciliary fluid height that allows normal ciliary activity. Apically expressed large-conductance, Ca(2+)-activated, and voltage-dependent K(+) (BK) channels provide an electrochemical gradient for Cl(-) secretion and thus play an important role for adequate airway hydration. Here we show that IFN-γ decreases ATP-mediated apical BK activation in normal human airway epithelial cells cultured at the air-liquid interface. IFN-γ decreased mRNA levels of KCNMA1 but did not affect total protein levels. Because IFN-γ upregulates dual oxidase (DUOX)2 and therefore H2O2 production, we hypothesized that BK inactivation could be mediated by BK oxidation. However, DUOX2 knockdown did not affect the IFN-γ effect on BK activity. IFN-γ changed mRNA levels of the BK β-modulatory proteins KCNMB2 (increased) and KCNMB4 (decreased) as well as leucine-rich repeat-containing protein (LRRC)26 (decreased). Mallotoxin, a BK opener only in the absence of LRRC26, showed that BK channels lost their association with LRRC26 after IFN-γ treatment. Finally, IFN-γ caused a decrease in ciliary beating frequency that was immediately rescued by apical fluid addition, suggesting that it was due to ASL volume depletion. These data were confirmed with direct ASL measurements using meniscus scanning. Overexpression of KCNMA1, the pore-forming subunit of BK, overcame the reduction of ASL volume induced by IFN-γ. Key experiments were repeated in cystic fibrosis cells and showed the same results. Therefore, IFN-γ induces mucociliary dysfunction through BK inactivation.

Antibiotic and anti-inflammatory therapies for cystic fibrosis

Cystic fibrosis (CF) lung disease is characterized by chronic bacterial infection and an unremitting inflammatory response, which are responsible for most of CF morbidity and mortality. The median expected survival has increased from <6 mo in 1940 to >38 yr now. This dramatic improvement, although not great enough, is due to the development of therapies directed at secondary disease pathologies, especially antibiotics. The importance of developing treatments directed against the vigorous inflammatory response was realized in the 1990s. New therapies directed toward the basic defect are now visible on the horizon. However, the impact of these drugs on downstream pathological consequences is unknown. It is likely that antibiotics and anti-inflammatory drugs will remain an important part of the maintenance regimen for CF in the foreseeable future. Current and future antibiotic and anti-inflammatory therapies for CF are reviewed.

Nebuliser systems for drug delivery in cystic fibrosis

BACKGROUND

Nebuliser systems are used to deliver medications to control the symptoms and the progression of lung disease in people with cystic fibrosis. Many types of nebuliser systems are available for use with various medications; however, there has been no previous systematic review which has evaluated these systems.

OBJECTIVES

To evaluate effectiveness, safety, burden of treatment and adherence to nebulised therapy using different nebuliser systems for people with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches, handsearching of relevant journals and abstract books of conference proceedings. We searched the reference lists of each study for additional publications and approached the manufacturers of both nebuliser systems and nebulised medications for published and unpublished data. Date of the most recent search: 15 Oct 2012.

SELECTION CRITERIA

Randomised controlled trials or quasi-randomised controlled trials comparing nebuliser systems including conventional nebulisers, vibrating mesh technology systems, adaptive aerosol delivery systems and ultrasonic nebuliser systems.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for inclusion. They also independently extracted data and assessed the risk of bias. A third author assessed studies where agreement could not be reached.

MAIN RESULTS

The search identified 40 studies with 20 of these (1936 participants) included in the review. These studies compared the delivery of tobramycin, colistin, dornase alfa, hypertonic sodium chloride and other solutions through the different nebuliser systems. This review demonstrates variability in the delivery of medication depending on the nebuliser system used. Conventional nebuliser systems providing higher flows, higher respirable fractions and smaller particles decrease treatment time, increase deposition and may be preferred by people with CF, as compared to conventional nebuliser systems providing lower flows, lower respirable fractions and larger particles. Nebulisers using adaptive aerosol delivery or vibrating mesh technology reduce treatment time to a far greater extent. Deposition (as a percentage of priming dose) is greater than conventional with adaptive aerosol delivery. Vibrating mesh technology systems may give greater deposition than conventional when measuring sputum levels, but lower deposition when measuring serum levels or using gamma scintigraphy. The available data indicate that these newer systems are safe when used with an appropriate priming dose, which may be different to the priming dose used for conventional systems. There is an indication that adherence is maintained or improved with systems which use these newer technologies, but also that some nebuliser systems using vibrating mesh technology may be subject to increased failures.

AUTHORS' CONCLUSIONS

Clinicians should be aware of the variability in the performance of different nebuliser systems. Technologies such as adaptive aerosol delivery and vibrating mesh technology have advantages over conventional systems in terms of treatment time, deposition as a percentage of priming dose, patient preference and adherence. There is a need for long-term randomised controlled trials of these technologies to determine patient-focused outcomes (such as quality of life and burden of care), safe and effective dosing levels of medications and clinical outcomes (such as hospitalisations and need for antibiotics) and an economic evaluation of their use.

Progress in cystic fibrosis and the CF Therapeutics Development Network

Cystic fibrosis (CF), the most common life-shortening genetic disorder in Caucasians, affects approximately 70 000 individuals worldwide. In 1998, the Cystic Fibrosis Foundation (CFF) launched the CF Therapeutics Development Network (CF-TDN) as a central element of its Therapeutics Development Programme. Designed to accelerate the clinical evaluation of new therapies needed to fulfil the CFF mission to control and cure CF, the CF-TDN has conducted 75 clinical trials since its inception, and has contributed to studies as varied as initial safety and proof of concept trials to pivotal programmes required for regulatory approval. This review highlights recent and significant research efforts of the CF-TDN, including a summary of contributions to studies involving CF transmembrane conductance regulator (CFTR) modulators, airway surface liquid hydrators and mucus modifiers, anti-infectives, anti-inflammatories, and nutritional therapies. Efforts to advance CF biomarkers, necessary to accelerate the therapeutic goals of the network, are also summarised.

Adjunctive therapy with interferon-gamma for the treatment of pulmonary tuberculosis: a systematic review

OBJECTIVE

To evaluate the efficacy and safety of adjunctive therapy using interferon-gamma (IFN-γ; an immunomodulator) for the treatment of pulmonary tuberculosis (TB).

METHODS

We conducted a systematic review of controlled clinical trials that compared anti-TB drugs in combination with IFN-γ with the same anti-TB drugs alone for the treatment of pulmonary TB.

RESULTS

Nine trials were identified, with IFN-γ being aerosolized or administered subcutaneously in one trial, aerosolized only in five trials, and administered intramuscularly in three trials. The methodology quality of all trials was rated 'C'. Meta-analysis of the trials with aerosolized IFN-γ showed statistical benefits on sputum negative conversion and chest radiograph: the pooled relative risk (RR) for conversion was 1.97 (95% confidence interval (CI) 1.20-3.24, p=0.008) after 1 month of treatment, 1.74 (95% CI 1.30-2.34, p=0.0002) after 2 months of treatment, 1.53 (95% CI 1.16-2.01, p=0.003) after 3 months of treatment, 1.57 (95% CI 1.20-2.06, p=0.001) after 6 months of treatment, and 1.55 (95% CI 1.17-2.05, p=0.002) at the end of treatment; the pooled RR for the chest radiograph was 1.38 (95% CI 1.10-1.17, p=0.006) at the end of treatment. For intramuscularly administered IFN-γ, meta-analysis of three trials showed its significant improvement on sputum negative conversion after 2 months of treatment. A randomized controlled trial with aerosolized and subcutaneously administered IFN-γ reported significant reductions in the symptoms of fever, wheeze, and night sweats in the IFN-γ-treated groups compared with the control group after 1 month of treatment. No patients discontinued treatment because of adverse effects caused by IFN-γ.

CONCLUSION

Adjuvant therapy using IFN-γ, especially by aerosol, might be beneficial to TB patients, but large randomized controlled trials are needed for further evaluation of its efficacy and safety considering the quality of the trials analyzed.

Clinical Use of Interferon-gamma

Interferon gamma (IFN-gamma), a pleotropic cytokine, has been shown to be important to the function of virtually all immune cells and both innate and adaptive immune responses. In 1986, early clinical trials of this cytokine began to evaluate its therapeutic potential. The initial studies focused on the tolerability and pharmacology of IFN-gamma and systematically determined its antitumor and anti-infection activities. In the 20-plus years since those first trials, IFN-gamma has been used in a wide variety of clinical indications, which are reviewed in this article.

Inhaled therapeutics for prevention and treatment of pneumonia

The lungs are the most common site of serious infection owing to their large surface area exposed to the external environment and minimum barrier defense. However, this architecture makes the lungs readily available for topical therapy. Therapeutic aerosols include those directed towards improving mucociliary clearance of pathogens, stimulation of innate resistance to microbial infection, cytokine stimulation of immune function and delivery of antibiotics. In our opinion inhaled antimicrobials are underused, especially in patients with difficult-to-treat lung infections. The use of inhaled antimicrobial therapy has become an important part of the treatment of airway infection with Pseudomonas aeruginosa in cystic fibrosis and the prevention of invasive fungal infection in patients undergoing heart and lung transplantation. Cytokine inhaled therapy has also been explored in the treatment of neoplastic and infectious disease. The choice of pulmonary drug delivery systems remains critical as air-jet and ultrasonic nebulizer may deliver sub-optimum drug concentration if not used properly. In future development of this field, we recommend an emphasis on the study of the use of aerosolized hypertonic saline solution to reduce pathogen burden in the airways of subjects infected with microbes of low virulence, stimulation of innate resistance to prevent pneumonia in immunocompromised subjects using cytokines or synthetic pathogen-associated molecular pattern analogues and more opportunities for the use of inhaled antimicrobials. These therapeutics are still in their infancy but show great promise.

Anti-inflammatory therapies for cystic fibrosis-related lung disease

Cystic fibrosis (CF) is an autosomal recessive disease affecting many organ systems. In the lung, the underlying ion transport defect in CF establishes a perpetuating cycle of impaired airway clearance, chronic endobronchial infection, and exuberant inflammation. The interrelated nature of these components of CF lung disease makes it likely that the most effective therapeutic strategies will include treatments of each of these. This chapter reviews the preclinical and clinical data focused on ways to better understand and particularly to limit inflammation in the CF airway. Anti-inflammatories are an attractive therapeutic target in CF with a proven ability to decrease the rate of decline in lung function. However, the inherent complexity of the inflammatory response combined with the obvious dependency on this response to contain infection and the side effect profiles of common anti-inflammatories have made identifying the most suitable agents challenging. Research continues to discover impairments in signaling events in CF that may contribute to the excessive inflammation seen clinically. Concurrent with these findings, promising new therapies are being evaluated to determine which agents will be most effective and well tolerated. Available data from studies commenced over the last two decades, which have generated both encouraging and disappointing results, are reviewed below.

Highlights of a workshop to discuss targeting inflammation in cystic fibrosis

A workshop to discuss anti-inflammatory approaches in the treatment of CF was held at Novartis Institutes for Biomedical Research (NIBR, Horsham, UK) in March 2008. Key opinion leaders in the field (Hugo De Jonge, Stuart Elborn, Erich Gulbins, Mike Konstan, Rick Moss, Scott Randell and Adriano Rossi), and NIBR scientists were brought together to collectively address three main aims: (i) to identify anti-inflammatory targets in CF, (ii) to evaluate the pros and cons of targeting specific cell types and (iii) to discuss model systems to profile potential therapeutic agents. The highlights of the workshop are captured in this review.

Prospects for use of interleukin-12 as a mucosal adjuvant for vaccination of humans to protect against respiratory pneumococcal infection

Mucosal vaccination against pneumococcal disease offers potential protection against otitis media, pneumonia and invasive disease, including providing herd benefit by reducing pathogen carriage. The major obstacle, however, remains the lack of a suitable adjuvant for use in humans. Animal models have demonstrated success of interleukin-12 (IL-12) as an adjuvant for mucosal vaccines using recombinant pneumococcal protein antigens. This review examines the biology of the IL-12 cytokine family, the toxicity of IL-12 in human studies and suggests approaches by which IL-12 could be developed as a mucosal adjuvant with pneumococcal protein based vaccines, for use in humans.

Traitement de l'inflammation bronchique dans la mucoviscidose

Cystic fibrosis airway inflammation is characterized by neutrophilic efflux and high levels of proinflammatory cytokines such as IL-8 and IL-6. Inhaled corticosteroids are widely used despite lack of evidence of efficacity. Despite evidence of efficacity of ibuprofen, many clinicians have chosen not to use this therapy because of concerns regarding potential side effects. Azithromycin has antiinflammatory properties and is effective in cystic fibrosis (CF) patients. Deoxyribonuclease (rhDNase) has been shown to improve lung function in patients with cystic fibrosis and may also have a positive effect on inflammation. Other antiinflammatory drugs are in the process of validation.

Repeated Aerosolized AAV-CFTR for Treatment of Cystic Fibrosis: A Randomized Placebo-Controlled Phase 2B Trial

Previous studies have demonstrated that delivery of a recombinant adeno-associated virus (AAV) vector encoding the complete human cystic fibrosis transmembrane regulator (CFTR) cDNA (tgAAVCF) to the nose, sinus, and lungs of subjects with cystic fibrosis (CF) was safe and well tolerated. In a small randomized, double-blind study of three doses of aerosolized tgAAVCF or placebo at 30-day intervals, encouraging but non-significant trends in pulmonary function and induced sputum interleukin 8 (IL-8) levels were seen at early time points. This larger study was conducted to verify these trends. One hundred and two subjects aged 12 years and older with mild-to-moderate cystic fibrosis (forced expiratory flow in 1 sec [FEV1]:60% predicted) were randomized to two aerosolized doses of 1x10(13)DNase-resistant particles of tgAAVCF (n=51) or matching placebo (n=51) administered 30 days apart. Although tgAAVCF was well tolerated, the study did not meet its primary efficacy end point of statistically significant improvement in FEV1 30 days after initial administration of tgAAVCF compared with placebo. There were no significant differences in spirometric lung function over time, induced sputum biologic markers, or days of antibiotic use in either treatment group. Thus repeated doses of aerosolized tgAAVCF were safe and well tolerated, but did not result in significant improvement in lung function over time. Because gene transfer is the simplest, most basic way to correct the underlying genetic defect that leads to disease in CF, further research is warranted to develop an effective gene transfer agent for the treatment of CF.

Sputum biomarkers of inflammation in cystic fibrosis lung disease

Pulmonary biomarkers are being used more frequently to monitor disease activity and evaluate response to treatment in individuals with cystic fibrosis (CF). This article summarizes the current state of knowledge of biomarkers of inflammation relevant to CF lung disease, and the tools to measure inflammation, with specific emphasis on sputum. Sputum is a rich, noninvasive source of biomarkers of inflammation and infection. Sputum induction, through the inhalation of hypertonic saline, has expanded the possibilities for monitoring airway inflammation and infection, especially in individuals who do not routinely expectorate sputum. We critically examine the existing data supporting the validity of sputum biomarkers in CF, with an eye toward their application as surrogate endpoints or outcome measures in CF clinical trials. Further validation studies are needed regarding the variability of inflammatory biomarker measurements, and to evaluate how these biomarkers relate to disease severity, and to longitudinal changes in lung function and other clinical endpoints. We highlight the need to incorporate sputum collection, by induction if necessary, and measurement of sputum biomarkers into routine CF clinical care. In the future, pulmonary biomarkers will likely be useful in predicting disease progression, indicating the onset and resolution of a pulmonary exacerbation, and assessing response to current therapies or candidate therapeutics.

Inflammation and anti-inflammatory therapies for cystic fibrosis

Cystic fibrosis lung disease is characterized by a self-propagating cycle of obstruction, infection, and inflammation. The inflammatory response, which accounts for the majority of the morbidity and mortality of the disease, begins early in life, becomes persistent, and is excessive relative to the bacterial burden. Therapies aimed at decreasing the inflammatory response represent a relatively new strategy for treatment. This article reviews the current state of the art of anti-inflammatory therapy in cystic fibrosis and introduces clinical trials that are underway.

Association between pulmonary function and sputum biomarkers in cystic fibrosis

RATIONALE

Sputum biomarkers of infection and inflammation are noninvasive measures that enable quantification of the complex pathophysiology of cystic fibrosis (CF) lung disease. Validation of these biomarkers as correlates of disease severity is a key step for their application.

OBJECTIVES

We constructed a large database from four multicenter studies to quantify the strength of association between expectorated sputum biomarkers and FEV(1.)

METHODS

FEV(1) (range, 25-120% predicted) and quantitative data on expectorated sputum biomarkers including free neutrophil elastase, IL-8, neutrophils, Pseudomonas aeruginosa, and Staphylococcus aureus were obtained from 269 participants (ages, 9-54 years) from 33 centers. Cross-sectional and longitudinal statistical analyses were performed to estimate associations between the markers and FEV(1), including the use of multivariable analyses.

RESULTS

Elastase was negatively correlated with FEV(1) (correlation [r] = -0.35; 95% confidence interval [CI]: -0.46, -0.22). On average, patients with CF who differed in their elastase measurements by 0.5 log differed in their FEV(1) values by -7.3% (95% CI: -9.7, -4.6). Neutrophil counts and IL-8 were also each negatively correlated. In a multivariable regression, elastase and neutrophil counts were able to explain the majority of variation in FEV(1). Elastase was further shown to have a significant longitudinal association with FEV(1), specifically a -2.9% decline in FEV(1) (95% CI: -5.0, -0.9) per 1-log increase in elastase. Although correlated with FEV(1), bacterial densities were unable to explain clinically meaningful differences in FEV(1) within and across patients.

CONCLUSIONS

These data support the role of sputum biomarkers as correlates of disease severity in a diverse CF population.

Advances in cystic fibrosis therapies

PURPOSE OF REVIEW

Over the past four decades, outcomes for patients with cystic fibrosis have improved dramatically. Major contributors to this improvement are a better understanding of disease pathogenesis and the systematic conduct of clinical trials evaluating new therapies designed to address these defects. This review describes recent developments in cystic fibrosis pulmonary therapies intended to treat various facets of the disease, including several treatments currently in development.

RECENT FINDINGS

The mainstays of therapy for cystic fibrosis, such as nutritional support and mechanical mucus clearance, are now supplemented with aggressive antibiotic regimens intended to suppress or eradicate bacterial colonization, anti-inflammatory agents, and new approaches that improve mucociliary clearance. Therapies in development address the underlying ion transport defect found in cystic fibrosis airways and also include small-molecule agents that restore function to the mutant cystic fibrosis transmembrane conductance regulator.

SUMMARY

Recent advances in therapies for cystic fibrosis offer the promise of improved outcomes and longer lives for patients with cystic fibrosis.

CF-Emerging therapies: Modulation inflammation

Persistent and dysregulated inflammation, combined with an exaggerated host response is a major contributor to CF lung disease. As lung disease progresses, neutrophil accumulation in the airways ensues. Modulation of CF airway inflammation may result in either beneficial or deleterious side effects, resulting in more harm than good. Antibiotics, in particular, macrolides which act as a long-term anti-inflammatory agent with an excellent safety profile, and dornase alpha, are very interesting agents; steroids are not indicated in CF except in very special situations, and other promising agents such as leukotriene modifiers, high-dose N-acetylcysteine, anti-elastase and anti-cytokines require further research. Research should focus on early treatment, before lung damage has occurred.

Inhaled cytokines and cytokine antagonists

Cytokine and cytokine antagonist have provided novel and effective therapies for many human diseases. A number of approved cytokines including the interferons (alpha, beta and gamma), interleukin-2 (IL-2), granulocyte macrophage colony stimulating factor (GM-CSF) as well as novel cytokine antagonists have been administered by the pulmonary route for both local lung disease and as a non-invasive method for systemic delivery. We review the published clinical experience of inhaled cytokines and cytokine antagonists. We discuss the limitations of the existing data and the type of clinical data desired to establish the advantages and safety of inhaled cytokines and cytokine antagonists.

Disease modifying genes in cystic fibrosis: therapeutic option or one-way road?

Cystic fibrosis (CF) is the most common genetic disease among Caucasians and is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. CF affects multiple organs but lung disease is the major determinant for morbidity and mortality. Many studies have focussed on the correlation between CFTR genotype and severity of disease. Since patients with identical CFTR mutations often show considerable variability in disease progression, genes other than CFTR are thought to have the potential to modify the course of lung disease in CF patients. Therefore, identification of CF-modifying genes has become the goal of several studies over the last 15 years. Pharmaceutical approaches for CF lung disease have been developed regardless of the underlying genetic defect and in general target symptoms such as airway obstruction and treatment of bacterial infection. Analysing the pathophysiological processes of modifiers may lead to the discovery of pathways involved in CF pathophysiology and possibly to the design of new therapeutics. The purpose of this review is not only to list potential CFTR modifier genes, but also to discuss new therapeutic strategies that could be derived from knowledge of these CF modifiers.

Anti-inflammatory medications for cystic fibrosis lung disease: selecting the most appropriate agent

The lung disease of cystic fibrosis (CF) is characterized by a self-sustaining cycle of airway obstruction, infection, and inflammation. Therapies aimed at decreasing the inflammatory response represent a relatively new strategy for treatment. Attention has focused primarily upon the therapeutic potential of corticosteroids and NSAIDs. Although beneficial, the use of systemic corticosteroids is limited by their unacceptable adverse effects. It is unclear if inhaled corticosteroids are a viable alternative, although their use in CF has dramatically increased in recent years. High-dose ibuprofen has been shown to slow progression of CF lung disease, but its use has not been widely adopted despite a favorable risk-benefit profile. Thus, other anti-inflammatory approaches are under investigation. Since the inflammatory response can be triggered by many stimuli and since the pathways activated by these stimuli produce many mediators, there are a plethora of targets for anti-inflammatory therapeutics. Specific antibodies, receptor antagonists, and counter-regulatory cytokines, such as interleukin (IL)-10 and interferon-gamma, inhibit the pro-inflammatory mediators responsible for the damaging inflammation in the CF airway, including tumor necrosis factor-alpha, IL-1beta and IL-8. Studies of molecules that modulate intracellular signaling cascades that lead to the production of inflammatory mediators, are underway in CF. For patients with established disease, recent and projected advances in therapies that are directed at neutrophil products, such as DNase, antioxidants, and protease inhibitors, hold great promise for limiting the consequences of the inflammatory response. To optimize anti-inflammatory therapy, it is necessary to understand the mechanism of action of these agents in the CF lung to determine which agents will be most beneficial, and to determine which therapies should be initiated at what age and stage of lung disease. Hope remains that correction of the abnormal CF transmembrane conductance regulator protein or gene replacement therapy will be curative. However, correction of the basic defect must also correct the dysregulated inflammatory response in order to be effective. Until those therapies aimed at repairing the basic defect are realized, limiting the effects of the inflammatory process will be important in slowing the decline in lung function and thus prolonging survival in patients with CF.