Anti-inflammatory approaches to cystic fibrosis airways disease

The Potential for Phospholipids in the Treatment of Airway Inflammation: An Unexplored Solution

Asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF) are major inflammatory respiratory diseases. Current mainstay therapy for asthma, and chronic obstructive pulmonary disease are corticosteroids, which have well-established side effect profiles. Phospholipids (PLs) are ubiquitous, diverse compounds with varying functions such as their structural role incell membrane, energy storage, and cell signaling.Recent advances in understanding PLs role as inflammatory mediators in the body as well as their widespread long-standing use as carrier molecules in drug delivery demonstrate the potential application of phospholipids in modulating inflammatory conditions. This review briefly explains the main mechanisms of inflammation in chronic respiratory diseases, currentanti-inflammatory treatments and areas of unmet need. The structural features, roles of endogenous and exogenous phospholipids, including their use as pharmaceutical excipients are reviewed. Current research on the immunomodulatory properties of PLs and their potentialapplication in inflammatory diseasesis the major section of this review. Considering the roles of PLs as inflammatory mediators and their safety profile established in pharmaceutical formulations, these small molecules demonstrate great potential as candidates in respiratory inflammation. Future studies need to focus on the immunomodulatory properties and the underlying mechanisms of phospholipids in respiratory inflammatory diseases.

Inhaled corticosteroids for cystic fibrosis

BACKGROUND

The reduction of lung inflammation is one of the goals of cystic fibrosis therapy. Inhaled corticosteroids are often used in this respect to treat children and adults with cystic fibrosis. The rationale for this is their potential to reduce lung damage arising from inflammation, as well as their effect on symptomatic wheezing. It is important to establish the current level of evidence for the risks and benefits of inhaled corticosteroids, especially in the light of their known adverse effects on growth. This is an update of a previously published review; however, due to the lack of research in this area, we do not envisage undertaking any further updates.

OBJECTIVES

To assess the effectiveness of taking regular inhaled corticosteroids compared to not taking them in children and adults 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 and handsearches of relevant journals and abstract books of conference proceedings. We requested information from pharmaceutical companies manufacturing inhaled corticosteroids and authors of identified trials.Date of most recent search of the Group's Trials Register: 19 November 2018.

SELECTION CRITERIA

Randomised or quasi-randomised trials, published and unpublished, comparing inhaled corticosteroids to placebo or standard treatment in individuals with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Two independent authors assessed methodological quality and risk of bias in trials using established criteria and extracted data using standard pro formas. The quality of the evidence was assessed using the GRADE criteria.

MAIN RESULTS

The searches identified 35 citations, of which 27 (representing 13 trials) were eligible for inclusion. These 13 trials reported the use of inhaled corticosteroids in 525 people with cystic fibrosis aged between 6 and 55 years. One was a withdrawal trial in 171 individuals who were already taking inhaled corticosteroids. Methodological quality and risk of bias were difficult to assess from published information.Objective measures of airway function were reported in most trials but were often incomplete and reported at different time points. We found no difference in forced expiratory volume in one second (FEV1) or forced vital capacity (FVC) % predicted in any of the trials, although the quality of the evidence was low due to risks of bias within the included trials and low participant numbers. We are uncertain whether inhaled corticosteroids result in an improvement in exercise tolerance, bronchial hyperreactivity or exacerbations as the quality of the evidence was very low. Data from one trial suggested that inhaled corticosteroids may make little or no difference to quality of life (low-quality evidence).Three trials reported adverse effects, but the quality of the evidence is low and so we are uncertain whether inhaled corticosteroids increase the risk of adverse effects. However, one study did show that growth was adversely affected by high doses of inhaled corticosteroids.

AUTHORS' CONCLUSIONS

Evidence from these trials is of low to very low quality and insufficient to establish whether inhaled corticosteroids are beneficial in cystic fibrosis, but withdrawal in those already taking them has been shown to be safe. There is some evidence they may cause harm in terms of growth. It has not been established whether long-term use is beneficial in reducing lung inflammation, which should improve survival, but it is unlikely this will be proven conclusively in a randomised controlled trial.

Inhaled corticosteroids for cystic fibrosis

BACKGROUND

Reduction of lung inflammation is one of the goals of cystic fibrosis therapy. Inhaled corticosteroids are often used to treat children and adults with cystic fibrosis. The rationale for this is their potential to reduce lung damage arising from inflammation, as well as their effect on symptomatic wheezing. It is important to establish the current level of evidence for the risks and benefits of inhaled corticosteroids, especially in the light of their known adverse effects on growth. This is an update of a previously published review.

OBJECTIVES

To assess the effectiveness of taking regular inhaled corticosteroids, compared to not taking them, in children and adults 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 and handsearches of relevant journals and abstract books of conference proceedings. We requested information from pharmaceutical companies manufacturing inhaled corticosteroids and authors of identified trials.Date of most recent search of the Group's Trials Register: 15 August 2016.

SELECTION CRITERIA

Randomised or quasi-randomised trials, published and unpublished, comparing inhaled corticosteroids to placebo or standard treatment in individuals with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Two independent authors assessed methodological quality and risk of bias in trials using established criteria and extracted data using standard pro formas.

MAIN RESULTS

The searches identified 34 citations, of which 26 (representing 13 trials) were eligible for inclusion. These 13 trials reported the use of inhaled corticosteroids in 506 people with cystic fibrosis aged between six and 55 years. One was a withdrawal trial in individuals who were already taking inhaled corticosteroids. Methodological quality and risk of bias were difficult to assess from published information. Many of the risk of bias judgements were unclear due to a lack of available information. Only two trials specified how participants were randomised and less than half of the included trials gave details on how allocation was concealed. Trials were generally judged to have a low risk of bias from blinding, except for two which were open label or did not use a placebo. There were some concerns that a number of trials had not been published in peer-reviewed journals, but the risk of bias from this was unclear. Inclusion criteria varied between trials, as did type and duration of treatment and timing of outcome assessments. Objective measures of airway function were reported in most trials but were often incomplete. Significant benefit has not been conclusively demonstrated. Four trials systematically documented adverse effects and growth was significantly affected in one study using high doses.

AUTHORS' CONCLUSIONS

Evidence from these trials is insufficient to establish whether inhaled corticosteroids are beneficial in cystic fibrosis, but withdrawal in those already taking them has been shown to be safe. There is some evidence they may cause harm in terms of growth. It has not been established whether long-term use is beneficial in reducing lung inflammation, which should improve survival, but it is unlikely this will be proven conclusively in a randomised controlled trial.

Physiological impact of abnormal lipoxin A₄ production on cystic fibrosis airway epithelium and therapeutic potential

Lipoxin A4 has been described as a major signal for the resolution of inflammation and is abnormally produced in the lungs of patients with cystic fibrosis (CF). In CF, the loss of chloride transport caused by the mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel gene results in dehydration, mucus plugging, and reduction of the airway surface liquid layer (ASL) height which favour chronic lung infection and neutrophil based inflammation leading to progressive lung destruction and early death of people with CF. This review highlights the unique ability of LXA4 to restore airway surface hydration, to stimulate airway epithelial repair, and to antagonise the proinflammatory program of the CF airway, circumventing some of the most difficult aspects of CF pathophysiology. The report points out novel aspects of the cellular mechanism involved in the physiological response to LXA4, including release of ATP from airway epithelial cell via pannexin channel and subsequent activation of and P2Y11 purinoreceptor. Therefore, inadequate endogenous LXA4 biosynthesis reported in CF exacerbates the ion transport abnormality and defective mucociliary clearance, in addition to impairing the resolution of inflammation, thus amplifying the vicious circle of airway dehydration, chronic infection, and inflammation.

Influence of macrolides, nutritional support and respiratory therapies in diabetes and normal glucose tolerance in cystic fibrosis. A retrospective analysis of a cohort of adult and younger patients

AIM

The development of cystic fibrosis related diabetes is associated with increased morbidity and mortality, worse nutritional status and lung function decline. It is known that patients with cystic fibrosis have a chronic inflammation status and that β pancreatic cells are very sensitive to oxidative stress. So these inflammatory mediators could contribute to the onset of progressive pancreatic fibrosis and, hence, to impair glucose metabolism. So, it could be hypothesized that the treatment with macrolides would protect and preserve β-cell function by decreasing pro-inflammatory cytokines and free oxidative radicals.

METHODS

We retrospectively analyzed a cohort of 64 patients affected of cystic fibrosis, older than 14 years, by using the first pathological 2-h oral glucose tolerance test; peripheral insulin resistance was calculated using the homeostasis model assessment for insulin resistance (HOMA - IR) and pancreatic β-cell function was estimated according to Wareham. The influence of macrolides, microbiological colonization, nutritional support and related clinical parameters were analyzed.

RESULTS

Comparing CFRD without FPG and NGT, and after adjustment for microbial colonization, the significance of the use of macrolides was lost (p=0.1), as a risk or protective factor for any of the studied groups. Non-significative associations were found in the use of macrolides, inhaled corticosteroids and nutritional support therapies within the different disorders of carbohydrate metabolism.

CONCLUSIONS

The anti-inflammatory and immunomodulating effect of macrolides did not seem to affect the β cell function or insulin resistance in patients with cystic fibrosis. The use of inhaled corticosteroids or nutritional supplements have not any influence in the carbohydrate metabolism. Further prospective studies are needed to analyze a potential protective role of macrolides in the development of carbohydrate metabolism alterations in cystic fibrosis.

Inhaled corticosteroids for cystic fibrosis

BACKGROUND

Reduction of lung inflammation is one of the goals of cystic fibrosis therapy. Inhaled corticosteroids are often used to treat children and adults with cystic fibrosis. The rationale for this is their potential to reduce lung damage arising from inflammation, as well as their effect on symptomatic wheezing. It is important to establish the current level of evidence for the risks and benefits of inhaled corticosteroids, especially in the light of their known adverse effects on growth.

OBJECTIVES

To assess the effectiveness of taking regular inhaled corticosteroids, compared to not taking them, in children and adults 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 and handsearches of relevant journals and abstract books of conference proceedings. We requested information from pharmaceutical companies manufacturing inhaled corticosteroids and authors of identified trials.Date of most recent search of the Group's Trials Register: 17 July 2014.

SELECTION CRITERIA

Randomised or quasi-randomised trials, published and unpublished, comparing inhaled corticosteroids to placebo or standard treatment in individuals with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Two independent authors assessed methodological quality and risk of bias in trials using established criteria and extracted data using standard pro formas.

MAIN RESULTS

The searches identified 34 citations, of which 26 (representing 13 trials) were eligible for inclusion. These 13 trials reported the use of inhaled corticosteroids in 506 people with cystic fibrosis aged between six and 55 years. One was a withdrawal trial in individuals who were already taking inhaled corticosteroids. Methodological quality and risk of bias were difficult to assess from published information. Many of the risk of bias judgements were unclear due to a lack of available information. Only two trials specified how participants were randomised and less than half of the included trials gave details on how allocation was concealed. Trials were generally judged to have a low risk of bias from blinding, except for two which were open label or did not use a placebo. There were some concerns that a number of trials had not been published in peer-reviewed journals, but the risk of bias from this was unclear. Inclusion criteria varied between trials, as did type and duration of treatment and timing of outcome assessments. Objective measures of airway function were reported in most trials but were often incomplete. Significant benefit has not been conclusively demonstrated. Four trials systematically documented adverse effects and growth was significantly affected in one study using high doses.

AUTHORS' CONCLUSIONS

Evidence from these trials is insufficient to establish whether inhaled corticosteroids are beneficial in cystic fibrosis, but withdrawal in those already taking them has been shown to be safe. There is some evidence they may cause harm in terms of growth. It has not been established whether long-term use is beneficial in reducing lung inflammation, which should improve survival, but it is unlikely this will be proven conclusively in a randomised controlled trial.

The role of Lipoxin A4 in Cystic Fibrosis Lung Disease

In Cystic Fibrosis (CF), mutations of the CFTR gene result in defective Cl(-) secretion and Na(+) hyperabsorption by epithelia which leads to airway lumen dehydration and mucus plugging and favours chronic bacterial colonization, persistent inflammation and progressive lung destruction. Beyond this general description, the pathogenesis of CF lung disease remains obscure due to an incomplete understanding of normal innate airway defense. This mini-review aims to highlight the role of the pro-resolution lipid mediator, Lipoxin A4, which is inadequately produced in CF, on several aspects of innate immunity that are altered in CF airway disease.

[National consensus regarding the prescription of inhaled corticosteroids in cystic fibrosis]

The conditions for the prescription of inhaled steroids (ISs) in cystic fibrosis (CF) are not well established.

AIM

To propose a formalized consensus agreement regarding the prescription of ISs in this disease.

MATERIAL AND METHODS

Application of the Delphi method in five thematic fields: indications, non-indications, dosage, precautions for use, and treatment follow-up.

RESULTS

Thirty of forty-nine (61 %) reference CF centers in France participated in the process, which comprised three rounds. Experts strongly agreed that ISs are indicated in the presence of pulmonary manifestations with wheezing, personal history of atopy, and/or bronchial hyper-responsiveness. In contrast, ISs are not indicated as first-line therapy for allergic bronchopulmonary aspergillosis. Strong agreement was reached regarding the daily dose of ISs, which should be similar to what is given in asthma and adapted to control symptoms so as to prescribe the smallest possible dose. Increasing the frequency of bacterial and fungal sputum analyses and eye (cataract) assessments was not deemed necessary. However, in case of prolonged (>6months) use of high-dose ISs, monitoring bone mineral density and the hypothalamic-pituitary-adrenal axis, in particular if itraconazole is concomitantly prescribed, was recommended.

CONCLUSION

This consensus statement defines a perimeter for the prescription of ISs in CF, with the aim of limiting their prescription (until new data are available).

Inhaled corticosteroids for cystic fibrosis

BACKGROUND

Reduction of lung inflammation is one of the goals of cystic fibrosis (CF) therapy. Inhaled corticosteroids (ICS) are often used to treat children and adults with CF. The rationale for this is their potential to reduce lung damage arising from inflammation, as well as their effect on symptomatic wheezing. It is important to establish the current level of evidence for the risks and benefits of ICS, especially in the light of their known adverse effects on growth.

OBJECTIVES

To assess the effectiveness of taking regular ICS, compared to not taking them, in children and adults with CF.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register, comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We requested information from pharmaceutical companies manufacturing inhaled corticosteroids and authors of identified trials.Date of most recent search of the Group's Trials Register: 03 September 2012.

SELECTION CRITERIA

Randomised or quasi-randomised trials, published and unpublished, comparing ICS to placebo or standard treatment in individuals with CF.

DATA COLLECTION AND ANALYSIS

Two independent authors assessed methodological quality of trials using established criteria and extracted data using standard pro formas.

MAIN RESULTS

The searches identified 34 citations, of which 26 (representing 13 trials) were eligible for inclusion. These 13 trials reported the use of ICS in 506 people with CF aged between 6 and 55 years. One trial was a withdrawal study in individuals who were already taking ICS. Methodological quality was difficult to assess from published information. Inclusion criteria varied between trials, as did type and duration of treatment and timing of outcome assessments. Objective measures of airway function were reported in most trials but were often incomplete. Significant benefit has not been conclusively demonstrated. Four trials systematically documented adverse effects and growth was significantly affected in one study using high doses.

AUTHORS' CONCLUSIONS

Evidence from these trials is insufficient to establish whether ICS are beneficial in CF, but withdrawal in those already taking them has been shown to be safe. There is some evidence they may cause harm in terms of growth. It has not been established whether long-term use is beneficial in reducing lung inflammation, which should improve survival, but it is unlikely this will be proven conclusively in a randomised controlled trial.

Corticosteroids in respiratory diseases in children

We review recent advances in the use of corticosteroids (CS) in pediatric lung disease. CS are frequently used, systemically or by inhalation. Their mechanisms of action in pulmonary diseases are ill defined. CS exert direct inhibitory effects on many inflammatory cells through genomic mechanisms. There is a time lag before clinical response, and the washout of effects is also prolonged. Prompt relief in some conditions, such as croup, may be related to airway mucosal vasoconstriction through a nongenomic mechanism. CS have proven beneficial roles in the treatment of asthma, croup, allergic bronchopulmonary aspergillosis, and subglottic hemangioma. In some conditions, such as bronchiolitis, cystic fibrosis, and bronchopulmonary dysplasia, their use is controversial and is not recommended routinely. In other conditions, such as tuberculosis, interstitial lung disease, acute lung aspiration, and acute respiratory distress syndrome, CS are often used empirically despite the lack of clear evidence of their benefit. New drug regimens, including the more flexible use of inhaled corticosteroids and long-acting β-agonists in asthma, the lack of efficacy of oral corticosteroids in preschool children with acute wheeze, the severe complications of systemic dexamethasone used to prevent bronchopulmonary dysplasia and thus more restricted use, and the beneficial effect of pulse high-dose intravenous methylprednisolone in patients with allergic bronchopulmonary aspergillosis or cystic fibrosis are among the major recent developments. There is concern about adverse effects, especially growth and adrenal suppression, induced by systemic CS in children. These have been reduced, but not eliminated, with the use of the inhaled route. The benefits must be weighed against the potential detrimental effects.

Regulation of normal and cystic fibrosis airway epithelial repair processes by TNF-α after injury

Chronic infection and inflammation have been associated with progressive airway epithelial damage in patients with cystic fibrosis (CF). However, the effect of inflammatory products on the repair capacity of respiratory epithelia is unclear. Our objective was to study the regulation of repair mechanisms by tumor necrosis factor-α (TNF-α), a major component of inflammation in CF, in a model of mechanical wounding, in two bronchial cell lines, non-CF NuLi and CF CuFi. We observed that TNF-α enhanced the NuLi and CuFi repair rates. Chronic exposure (24–48 h) to TNF-α augmented this stimulation as well as the migration rate during repair. The cellular mechanisms involved in this stimulation were then evaluated. First, we discerned that TNF-α induced metalloproteinase-9 release, epidermal growth factor (EGF) shedding, and subsequent EGF receptor transactivation. Second, TNF-α-induced stimulation of the NuLi and CuFi wound-closure rates was prevented by GM6001 (metalloproteinase inhibitor), EGF antibody (to titrate secreted EGF), and EGF receptor tyrosine kinase inhibitors. Furthermore, we recently reported a relationship between the EGF response and K+channel function, both controlling bronchial repair. We now show that TNF-α enhances KvLQT1 and KATPcurrents, while their inhibition abolishes TNF-α-induced repair stimulation. These results indicate that the effect of TNF-α is mediated, at least in part, through EGF receptor transactivation and K+channel stimulation. In contrast, cell proliferation during repair was slowed by TNF-α, suggesting that TNF-α could exert contrasting actions on repair mechanisms of CF airway epithelia. Finally, the stimulatory effect of TNF-α on airway wound repair was confirmed on primary airway epithelial cells, from non-CF and CF patients.

New and investigational treatments in cystic fibrosis

Cystic fibrosis (CF) is an autosomal recessive disorder that affects approximately 1 in 3,000 Caucasian births, or 30,000 individuals in the US and 70,000 worldwide. The discovery of the CF gene, isolation of the CFTR protein and understanding of molecular mechanisms behind the clinical expression of CF are being translated into newer treatments. Treatments for CF and its manifestations are discussed in this article including inhaled antibiotics, hydrator therapies, anti-inflammatory agents and protein modifiers. New and experimental treatments that are in development are also discussed. Outcomes for these treatments are forced expiratory volume in one second (FEV(1)) improvement, CF-related quality of life, use of intravenous antibiotics and frequency of exacerbations and hospitalizations.

Interplay of cysteinyl leukotrienes and TGF-β in the activation of hepatic stellate cells from Schistosoma mansoni granulomas

Hepatic stellate cells (HSCs) have a critical role in liver physiology, and in the pathogenesis of liver inflammation and fibrosis. Here, we investigated the interplay between leukotrienes (LT) and TGF-β in the activation mechanisms of HSCs from schistosomal granulomas (GR-HSCs). First, we demonstrated that GR-HSCs express 5-lipoxygenase (5-LO), as detected by immunolocalization in whole cells and confirmed in cell lysates through western blotting and by mRNA expression through RT-PCR. Moreover, mRNA expression of 5-LO activating protein (FLAP) and LTC(4)-synthase was also documented, indicating that GR-HSCs have the molecular machinery required for LT synthesis. Morphological analysis of osmium and Oil-Red O-stained HSC revealed large numbers of small lipid droplets (also known as lipid bodies). We observed co-localization of lipid droplet protein marker (ADRP) and 5-LO by immunofluorescence microscopy. We demonstrated that GR-HSCs were able to spontaneously release cysteinyl-LTs (CysLTs), but not LTB(4,) into culture supernatants. CysLT production was highly enhanced after TGF-β-stimulation. Moreover, the 5-LO inhibitor zileuton and 5-LO gene deletion were able to inhibit the TGF-β-stimulated proliferation of GR-HSCs, suggesting a role for LTs in HSC activation. Here, we extend the immunoregulatory function of HSC by demonstrating that HSC from liver granulomas of schistosome-infected mouse are able to release Cys-LTs in a TGF-β-regulated manner, potentially impacting pathogenesis and liver fibrosis in schistosomiasis.

Inhaled corticosteroids for cystic fibrosis

BACKGROUND

Reduction of lung inflammation is one of the goals of cystic fibrosis (CF) therapy. Inhaled corticosteroids (ICS) are often used to treat children and adults with CF. The rationale for this is their potential to reduce lung damage arising from inflammation, as well as their effect on symptomatic wheezing. It is important to establish the current level of evidence for the risks and benefits of ICS, especially in the light of their known adverse effects on growth.

OBJECTIVES

To assess the effectiveness of taking regular ICS, compared to not taking them, in children and adults with CF.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register, comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We requested information from pharmaceutical companies manufacturing inhaled corticosteroids and authors of identified trials.Date of most recent search of the Group's Trials Register: June 2008.

SELECTION CRITERIA

Randomised or quasi-randomised trials, published and unpublished, comparing ICS to placebo or standard treatment in individuals with CF.

DATA COLLECTION AND ANALYSIS

Two independent authors assessed methodological quality of trials using established criteria and extracted data using standard pro formas.

MAIN RESULTS

Thirty citations were identified by the searches, of which 25, representing 13 trials were eligible for inclusion. These 13 trials reported the use of ICS in 506 people with CF aged between 6 and 55 years. One trial was a withdrawal study in individuals who were already taking ICS. Methodological quality was difficult to assess from published information. Inclusion criteria varied between trials, as did type and duration of treatment and timing of outcome assessments. Objective measures of airway function were reported in most trials but were often incomplete. Significant benefit has not been conclusively demonstrated. Four trials systematically documented adverse effects and growth was significantly affected in one study using high doses.

AUTHORS' CONCLUSIONS

Evidence from these trials is insufficient to establish whether ICS are beneficial in CF, but withdrawal in those already taking them has been shown to be safe. There is some evidence they may cause harm in terms of growth. It has not been established whether long-term use is beneficial in reducing lung inflammation, which should improve survival, but it is unlikely this will be proven conclusively in a randomised controlled trial.

Clinical trials in infants with cystic fibrosis detected following newborn screening

Despite the wide implementation of newborn screening for cystic fibrosis there have been few clinical trials aimed at reducing the burden of lung disease in screened infants. Emerging tools such as infant lung function and low-dose computed tomography (CT) provide early indicators of lung disease and could be effective outcome measures in randomized controlled trials (RCTs) of interventions that aim to delay or prevent the onset of bronchiectasis. The most recent data suggest that strategies to reduce neutrophilic inflammation and prevent infection are good candidates for RCTs. However, cooperation between centres is needed if they are to be large enough to detect differences due to the intervention that otherwise may be masked by subtle differences in management practices between centres, and to detect rare but significant adverse effects.

Cystic fibrosis: a review of pulmonary and nutritional therapies

In summary, there is a significant interplay between the pulmonary manifestations and nutritional status of CF patients. The advances in CF clinical care in the past 2 decades are mainly attributed to anti-infective therapy as well as aggressive nutritional management. Currently, there are multiple therapeutic agents that are in clinical trial that target either the underlying CFTR defect or the downstream effects of CFTR. The broad spectrum of therapeutic agents being studied as well as the advances in therapies that target the underlying CFTR defect are exciting, making it likely that at least one of the treatments will make a major difference in how we will treat CF in the future.