Using Negative Control Outcomes and Difference-in-Differences Analysis to Estimate Treatment Effects in an Entirely Treated Cohort: The Effect of Ivacaftor in Cystic Fibrosis.

When an entire cohort of patients receives a treatment, it is difficult to estimate the treatment effect in the treated because there are no directly comparable untreated patients. Attempts can be made to find a suitable control group (e.g., historical controls), but underlying differences between the treated and untreated can result in bias. Here we show how negative control outcomes combined with difference-in-differences analysis can be used to assess bias in treatment effect estimates and obtain unbiased estimates under certain assumptions. Causal diagrams and potential outcomes are used to explain the methods and assumptions. We apply the methods to UK Cystic Fibrosis Registry data to investigate the effect of ivacaftor, introduced in 2012 for a subset of the cystic fibrosis population with a particular genotype, on lung function and annual rate (days/year) of receiving intravenous (IV) antibiotics (i.e., IV days). We consider 2 negative control outcomes: outcomes measured in the pre-ivacaftor period and outcomes among persons ineligible for ivacaftor because of their genotype. Ivacaftor was found to improve lung function in year 1 (an approximately 6.5-percentage-point increase in ppFEV1), was associated with reduced lung function decline (an approximately 0.5-percentage-point decrease in annual ppFEV1 decline, though confidence intervals included 0), and reduced the annual rate of IV days (approximately 60% over 3 years).

Heterogeneity of treatment response in bronchiectasis clinical trials.

BACKGROUND: Recent randomised clinical trials in bronchiectasis have failed to reach their primary end-points, suggesting a need to reassess how we measure treatment response. Exacerbations, quality of life (QoL) and lung function are the most common end-points evaluated in bronchiectasis clinical trials. We aimed to determine the relationship between responses in terms of reduced exacerbations, improved symptoms and lung function in bronchiectasis. METHODS: We evaluated treatment response in three randomised clinical trials that evaluated mucoactive therapy (inhaled mannitol), an oral anti-inflammatory/antibiotic (azithromycin) and an inhaled antibiotic (aztreonam). Treatment response was defined by an absence of exacerbations during follow-up, an improvement of QoL above the minimum clinically important difference and an improvement in forced expiratory volume in 1 s (FEV1) of ≥100 mL from baseline. RESULTS: Cumulatively the three trials included 984 patients. Changes in FEV1, QoL and exacerbations were heterogeneous in all trials analysed. Improvements in QoL were not correlated to changes in FEV1 in the azithromycin and aztreonam trials (r= -0.17, p=0.1 and r=0.04, p=0.4, respectively) and weakly correlated in the mannitol trial (r=0.22, p<0.0001). An important placebo effect was observed in all trials, especially regarding improvements in QoL. Clinical meaningful lung function improvements were rare across all trials evaluated, suggesting that FEV1 is not a responsive measure in bronchiectasis. CONCLUSIONS: Improvements in lung function, symptoms and exacerbation frequency are dissociated in bronchiectasis. FEV1 is poorly responsive and poorly correlated with other key outcome measures. Clinical parameters are poorly predictive of treatment response, suggesting the need to develop biomarkers to identify responders.

Mediation of the total effect of cystic fibrosis-related diabetes on mortality: A UK Cystic Fibrosis Registry cohort study.

AIM: To investigate whether the effect of cystic fibrosis-related diabetes (CFRD) on the composite outcome of mortality or transplant could act through lung function, pulmonary exacerbations and/or nutritional status. METHODS: A retrospective cohort of adult cystic fibrosis (CF) patients who had not been diagnosed with CFRD were identified from the UK Cystic Fibrosis Registry (n = 2750). Rate of death or transplant was compared between patients who did and did not develop CFRD (with insulin use) during follow-up using Poisson regression, separately by sex. Causal mediation methods were used to investigate whether lung function, pulmonary exacerbations and nutritional status lie on the causal pathway between insulin-treated CFRD and mortality/transplant. RESULTS: At all ages, the mortality/transplant rate was higher in both men and women diagnosed with CFRD. Pulmonary exacerbations were the strongest mediator of the effect of CFRD on mortality/transplant, with an estimated 15% [95% CI: 7%, 28%] of the effect at 2 years post-CFRD diagnosis attributed to exacerbations, growing to 24% [95% CI: 9%, 46%] at 4 years post-diagnosis. Neither lung function nor nutritional status were found to be significant mediators of this effect. Estimates were similar but with wider confidence intervals in a cohort that additionally included people with CFRD but not using insulin. CONCLUSION: There is evidence that pulmonary exacerbations mediate the effect of CFRD on mortality but, as they are estimated to mediate less than one-quarter of the total effect, the mechanism through which CFRD influences survival may involve other factors.

Data from the US and UK cystic fibrosis registries support disease modification by CFTR modulation with ivacaftor.

BACKGROUND: Ivacaftor is the first cystic fibrosis transmembrane conductance regulator (CFTR) modulator demonstrating clinical benefit in patients with cystic fibrosis (CF). As ivacaftor is intended for chronic, lifelong use, understanding long-term effects is important for patients and healthcare providers. OBJECTIVE: This ongoing, observational, postapproval safety study evaluates clinical outcomes and disease progression in ivacaftor-treated patients using data from the US and the UK CF registries following commercial availability. METHODS: Annual analyses compare ivacaftor-treated and untreated matched comparator patients for: risks of death, transplantation, hospitalisation, pulmonary exacerbation; prevalence of CF-related complications and microorganisms and lung function changes in a subset of patients who initiated ivacaftor in the first year of commercial availability. Results from the 2014 analyses (2 and 3 years following commercial availability in the UK and USA, respectively) are presented here. RESULTS: Analyses included 1256 ivacaftor-treated and 6200 comparator patients from the USA and 411 ivacaftor-treated and 2069 comparator patients from the UK. No new safety concerns were identified based on the evaluation of clinical outcomes included in the analyses. As part of safety evaluations, ivacaftor-treated US patients were observed to have significantly lower risks of death (0.6% vs 1.6%, p=0.0110), transplantation (0.2% vs 1.1%, p=0.0017), hospitalisation (27.5% vs 43.1%, p<0.0001) and pulmonary exacerbation (27.8% vs 43.3%, p<0.0001) relative to comparators; trends were similar in the UK. In both registries, ivacaftor-treated patients had a lower prevalence of CF-related complications and select microorganisms and had better preserved lung function. CONCLUSIONS: While general limitations of observational research apply, analyses revealed favourable results for clinically important outcomes among ivacaftor-treated patients, adding to the growing body of literature supporting disease modification by CFTR modulation with ivacaftor. EU PAS REGISTRATION NUMBER: EUPAS4270.

Laboratory Diagnosis and Characterization of Fungal Disease in Patients with Cystic Fibrosis (CF): A Survey of Current UK Practice in a Cohort of Clinical Microbiology Laboratories.

There is much uncertainty as to how fungal disease is diagnosed and characterized in patients with cystic fibrosis (CF). A 19-question anonymous electronic questionnaire was developed and distributed to ascertain current practice in clinical microbiology laboratories providing a fungal laboratory service to CF centres in the UK. Analyses of responses identified the following: (1) current UK laboratory practice, in general, follows the current guidelines, but the scope and diversity of what is currently being delivered by laboratories far exceeds what is detailed in the guidelines; (2) there is a lack of standardization of fungal tests amongst laboratories, outside of the current guidelines; (3) both the UK CF Trust Laboratory Standards for Processing Microbiological Samples from People with Cystic Fibrosis and the US Cumulative Techniques and Procedures in Clinical Microbiology (Cumitech) Guidelines 43 Cystic Fibrosis Microbiology need to be updated to reflect both new methodological innovations, as well as better knowledge of fungal disease pathophysiology in CF; (4) there is a need for clinical medicine to decide upon a stratification strategy for the provision of new fungal assays that will add value to the physician in the optimal management of CF patients; (5) there is also a need to rationale what assays should be performed at local laboratory level and those which are best served at National Mycology Reference Laboratory level; and (6) further research is required in developing laboratory assays, which will help ascertain the clinical importance of 'old' fungal pathogens, as well as 'emerging' fungal pathogens.

Pseudomonas aeruginosa adaptation and diversification in the non-cystic fibrosis bronchiectasis lung.

To characterise Pseudomonas aeruginosa populations during chronic lung infections of non-cystic fibrosis bronchiectasis patients, we used whole-genome sequencing to 1) assess the diversity of P. aeruginosa and the prevalence of multilineage infections; 2) seek evidence for cross-infection or common source acquisition; and 3) characterise P. aeruginosa adaptations.189 isolates, obtained from the sputa of 91 patients attending 16 adult bronchiectasis centres in the UK, were whole-genome sequenced.Bronchiectasis isolates were representative of the wider P. aeruginosa population. Of 24 patients from whom multiple isolates were examined, there were seven examples of multilineage infections, probably arising from multiple infection events. The number of nucleotide variants between genomes of isolates from different patients was in some cases similar to the variations observed between isolates from individual patients, implying the possible occurrence of cross-infection or common source acquisition.Our data indicate that during infections of bronchiectasis patients, P. aeruginosa populations adapt by accumulating loss-of-function mutations, leading to changes in phenotypes including different modes of iron acquisition and variations in biofilm-associated polysaccharides. The within-population diversification suggests that larger scale longitudinal surveillance studies will be required to capture cross-infection or common source acquisition events at an early stage.

Antipseudomonal Bacteriophage Reduces Infective Burden and Inflammatory Response in Murine Lung.

As antibiotic resistance increases, there is a need for new therapies to treat infection, particularly in cystic fibrosis (CF), where Pseudomonas aeruginosa is a ubiquitous pathogen associated with increased morbidity and mortality. Bacteriophages are an attractive alternative treatment, as they are specific to the target bacteria and have no documented side effects. The efficacy of phage cocktails was established in vitro. Two P. aeruginosa strains were taken forward into an acute murine infection model with bacteriophage administered either prophylactically, simultaneously, or postinfection. The infective burden and inflammation in bronchoalveolar lavage fluid (BALF) were assessed at various times. With low infective doses, both control mice and those undergoing simultaneous phage treatment cleared P. aeruginosa infection at 48 h, but there were fewer neutrophils in BALF of phage-treated mice (median, 73.2 × 10(4)/ml [range, 35.2 to 102.1 × 10(4)/ml] versus 174 × 10(4)/ml [112.1 to 266.8 × 10(4)/ml], P < 0.01 for the clinical strain; median, 122.1 × 10(4)/ml [105.4 to 187.4 × 10(4)/ml] versus 206 × 10(4)/ml [160.1 to 331.6 × 10(4)/ml], P < 0.01 for PAO1). With higher infective doses of PAO1, all phage-treated mice cleared P. aeruginosa infection at 24 h, whereas infection persisted in all control mice (median, 1,305 CFU/ml [range, 190 to 4,700 CFU/ml], P < 0.01). Bacteriophage also reduced CFU/ml in BALF when administered postinfection (24 h) and both CFU/ml and inflammatory cells in BALF when administered prophylactically. A reduction in soluble inflammatory cytokine levels in BALF was also demonstrated under different conditions. Bacteriophages are efficacious in reducing both the bacterial load and inflammation in a murine model of P. aeruginosa lung infection. This study provides proof of concept for future clinical trials in patients with CF.

US Cystic Fibrosis Foundation and European Cystic Fibrosis Society consensus recommendations for the management of non-tuberculous mycobacteria in individuals with cystic fibrosis.

Non-tuberculous mycobacteria (NTM) are ubiquitous environmental organisms that can cause chronic pulmonary infection, particularly in individuals with pre-existing inflammatory lung disease such as cystic fibrosis (CF). Pulmonary disease caused by NTM has emerged as a major threat to the health of individuals with CF but remains difficult to diagnose and problematic to treat. In response to this challenge, the US Cystic Fibrosis Foundation (CFF) and the European Cystic Fibrosis Society (ECFS) convened an expert panel of specialists to develop consensus recommendations for the screening, investigation, diagnosis and management of NTM pulmonary disease in individuals with CF. Nineteen experts were invited to participate in the recommendation development process. Population, Intervention, Comparison, Outcome (PICO) methodology and systematic literature reviews were employed to inform draft recommendations. An anonymous voting process was used by the committee to reach consensus. All committee members were asked to rate each statement on a scale of: 0, completely disagree, to 9, completely agree; with 80% or more of scores between 7 and 9 being considered 'good' agreement. Additionally, the committee solicited feedback from the CF communities in the USA and Europe and considered the feedback in the development of the final recommendation statements. Three rounds of voting were conducted to achieve 80% consensus for each recommendation statement. Through this process, we have generated a series of pragmatic, evidence-based recommendations for the screening, investigation, diagnosis and treatment of NTM infection in individuals with CF as an initial step in optimising management for this challenging condition.

US Cystic Fibrosis Foundation and European Cystic Fibrosis Society consensus recommendations for the management of non-tuberculous mycobacteria in individuals with cystic fibrosis: executive summary.

Non-tuberculous mycobacteria (NTM) are ubiquitous environmental organisms that can cause chronic pulmonary infection, particularly in individuals with pre-existing inflammatory lung disease, such as cystic fibrosis (CF). Pulmonary disease (PD) caused by NTM has emerged as a major threat to the health of individuals with CF, but remains difficult to diagnose and problematic to treat. In response to this challenge, the US Cystic Fibrosis Foundation (CFF) and the European Cystic Fibrosis Society (ECFS) convened a panel of 19 experts to develop consensus recommendations for the screening, investigation, diagnosis and management of NTM-PD in individuals with CF. PICO (population, intervention, comparison, outcome) methodology and systematic literature reviews were employed to inform draft recommendations, which were then modified to achieve consensus and subsequently circulated for public consultation within the USA and European CF communities. We have thus generated a series of pragmatic, evidence-based recommendations as an initial step in optimising management for this challenging condition.

A longitudinal study characterising a large adult primary ciliary dyskinesia population.

Primary ciliary dyskinesia (PCD) in adults has not been well described. In this retrospective observational study we aimed to characterise a large adult population and identify features associated with disease progression.We retrospectively analysed 151 adult patients at a single tertiary centre at baseline and longitudinally for a median of 7 years.We found significant variation in age at diagnosis (median 23.5 years; range <1-72 years). Older age at diagnosis was associated with impaired baseline forced expiratory volume in 1 s (FEV1) (r= -0.30, p=0.01) and increased Pseudomonas aeruginosa colonisation (difference in medians 17 years (95% CI 4.5-20 years); p=0.002). Lung function decline was estimated at FEV1 decline of 0.49% predicted per year. Lung function decline was associated with ciliary ultrastructure, with microtubular defect patients having the greatest decline (p=0.04). High-resolution computed tomography (HRCT) scores of severity of bronchial wall dilatation (p<0.001) and extent of bronchiectasis (p=0.03) additionally showed evidence of modifying FEV1 decline with age.Our study reveals that a large proportion of adult PCD patients are diagnosed late, with impaired FEV1 and increased P. aeruginosa colonisation. Increased disease burden on HRCT and ciliary ultrastructure may predict progressive lung function decline. This study characterises a large adult PCD population, identifies features associated with disease progression and highlights the need for prospective trials to determine whether early diagnosis of high-risk subgroups alongside optimal management can modify disease progression.

Chronic Infection by Mucoid Pseudomonas aeruginosa Associated with Dysregulation in T-Cell Immunity to Outer Membrane Porin F.

RATIONALE: Pseudomonas aeruginosa (PA) is an environmental pathogen that commonly infects individuals with cystic fibrosis (CF) and non-CF bronchiectasis, impacting morbidity and mortality. To understand the pathobiology of interactions between the bacterium and host adaptive immunity and to inform rational vaccine design, it is important to understand the adaptive immune correlates of disease. OBJECTIVES: To characterize T-cell immunity to the PA antigen outer membrane porin F (OprF) by analyzing immunodominant epitopes in relation to infection status. METHODS: Patients with non-CF bronchiectasis were stratified by frequency of PA isolation. T-cell IFN-γ immunity to OprF and its immunodominant epitopes was characterized. Patterns of human leukocyte antigen (HLA) restriction of immunodominant epitopes were defined using HLA class II transgenic mice. Immunity was characterized with respect to cytokine and chemokine secretion, antibody response, and T-cell activation transcripts. MEASUREMENTS AND MAIN RESULTS: Patients were stratified according to whether PA was never, sometimes (<50%), or frequently (≥50%) isolated from sputum. Patients with frequent PA sputum-positive isolates were more likely to be infected by mucoid PA, and they showed a narrow T-cell epitope response and a relative reduction in Th1 polarizing transcription factors but enhanced immunity with respect to antibody production, innate cytokines, and chemokines. CONCLUSIONS: We have defined the immunodominant, HLA-restricted T-cell epitopes of OprF. Our observation that chronic infection is associated with a response of narrowed specificity, despite strong innate and antibody immunity, may help to explain susceptibility in these individuals and pave the way for better vaccine design to achieve protective immunity.

Children and young adults with CF in the USA have better lung function compared with the UK.

BACKGROUND: People with cystic fibrosis (CF) are managed differently in the USA and UK providing an opportunity to learn from differences in practice patterns. OBJECTIVES: To compare cross-sectional demographics, practice patterns and clinical outcomes between US and UK CF patients. METHODS: This was a cross-sectional study using 2010 data from patients in the US Cystic Fibrosis Foundation and the UK Cystic Fibrosis patient registries. The a priori outcome measures of interest were lung function and nutritional status. Descriptive statistics and two sample comparisons were performed. Stratification and multivariable linear regression were used to adjust for confounding. RESULTS: The study cohort included 13 777 children and 11 058 adults from the USA and 3968 children and 3965 adults from the UK. In children, mean body mass index centiles were similar. Lung function (FEV1 and FVC% predicted) was significantly higher in US patients ages 6-25 years of age. In a regression model adjusted for only age, FEV1% predicted was on average 3.31% of predicted (95% CI 2.65 to 3.96) higher in the USA compared with the UK. When adjusted for age, age at diagnosis, gender, pancreatic insufficiency and genotype, FEV1% predicted was on average 3.03% of predicted (95% CI 2.37 to 3.69) higher in the USA compared with the UK These differences persisted despite adjustment for possible confounders. Hypertonic saline and dornase alfa were much more commonly prescribed in US children. CONCLUSIONS: Children and young adults with CF have better lung function in the USA compared with the UK despite similar nutritional status.

The reproducibility and responsiveness of the lung clearance index in bronchiectasis.

Lung clearance index (LCI) is a potential clinical outcome marker in bronchiectasis. Its responsiveness to therapeutic intervention has not been determined. This study evaluates its responsiveness to a session of physiotherapy and intravenous antibiotic treatment of an exacerbation.32 stable and 32 exacerbating bronchiectasis patients and 26 healthy controls were recruited. Patients had LCI and lung function performed before and after physiotherapy on two separate occasions in the stable patients and at the beginning and end of an intravenous antibiotic course in the exacerbating patients.LCI was reproducible between visits in 25 stable patients, with an intraclass correlation of 0.978 (0.948, 0.991; p<0.001). There was no significant difference in LCI (mean±sd) between stable 11.91±3.39 and exacerbating patients 12.76±3.47, but LCI was significantly higher in both bronchiectasis groups compared with healthy controls (7.36±0.99) (p<0.001). Forced expiratory volume in 1 s improved after physiotherapy, as did alveolar volume after intravenous antibiotics, but LCI did not change significantly.LCI is reproducible in stable bronchiectasis but unlike conventional lung function tests, is unresponsive to two short-term interventions and hence is unlikely to be a useful clinical tool for short-term acute assessment in these patients. Further evaluation is required to establish its role in milder disease and in the evaluation of long-term interventions.

Inhaled colistin in patients with bronchiectasis and chronic Pseudomonas aeruginosa infection.

RATIONALE: Chronic infection with Pseudomonas aeruginosa is associated with an increased exacerbation frequency, a more rapid decline in lung function, and increased mortality in patients with bronchiectasis. OBJECTIVES: To perform a randomized placebo-controlled study assessing the efficacy and safety of inhaled colistin in patients with bronchiectasis and chronic P. aeruginosa infection. METHODS: Patients with bronchiectasis and chronic P. aeruginosa infection were enrolled within 21 days of completing a course of antipseudomonal antibiotics for an exacerbation. Participants were randomized to receive colistin (1 million IU; n = 73) or placebo (0.45% saline; n = 71) via the I-neb twice a day, for up to 6 months. MEASUREMENTS AND MAIN RESULTS: The primary endpoint was time to exacerbation. Secondary endpoints included time to exacerbation based on adherence recorded by the I-neb, P. aeruginosa bacterial density, quality of life, and safety parameters. All analyses were on the intention-to-treat population. Median time (25% quartile) to exacerbation was 165 (42) versus 111 (52) days in the colistin and placebo groups, respectively (P = 0.11). In adherent patients (adherence quartiles 2-4), the median time to exacerbation was 168 (65) versus 103 (37) days in the colistin and placebo groups, respectively (P = 0.038). P. aeruginosa density was reduced after 4 (P = 0.001) and 12 weeks (P = 0.008) and the St. George's Respiratory Questionnaire total score was improved after 26 weeks (P = 0.006) in the colistin versus placebo patients, respectively. There were no safety concerns. CONCLUSIONS: Although the primary endpoint was not reached, this study shows that inhaled colistin is a safe and effective treatment in adherent patients with bronchiectasis and chronic P. aeruginosa infection. Clinical trial registered with http://www.isrctn.org/ (ISRCTN49790596).

Relationship between pulmonary exacerbations and daily physical activity in adults with cystic fibrosis.

BACKGROUND: The aim of this study was to examine the relationship between pulmonary exacerbations and physical activity (PA) in adults with cystic fibrosis (CF). METHODS: We grouped adults with CF according to their exacerbation status in the year before study enrollment: (1) <1 exacerbation/year; (2) 1-2 exacerbations/year; and (3) >2 exacerbations/year. PA was assessed objectively by means of an accelerometer at the time of study enrollment. RESULTS: Patients with >2 exacerbations/year spent less time in PA; specifically, fewer activities of mild intensity [>3 metabolic equivalents (METs)], and lower active energy expenditure (P = 0.01 and P = 0.03, respectively). After correcting for relevant confounders, PA levels were not related to the exacerbation frequency in the preceding year. PA at moderate intensity (4.8-7.2 METs) or greater (> 7.2 METs) was independently associated with gender and FEV1 % predicted (P = 0.007 and P = 0.04, respectively). Compared with men, women had reduced vigorous activities (P = 0.01) and active energy expenditure (P = 0.01). CONCLUSIONS: Adult CF patients with more pulmonary exacerbations in the preceding year have more advanced disease and are less active than their peers. PA was independently associated with gender and airflow obstruction. Gender differences in PA are evident in CF adults.

Inhaled mannitol for non-cystic fibrosis bronchiectasis: a randomised, controlled trial.

RATIONALE: Bronchiectasis is characterised by excessive production of mucus and pulmonary exacerbations. Inhaled osmotic agents may enhance mucociliary clearance, but few long-term clinical trials have been conducted. OBJECTIVES: To determine the impact of inhaled mannitol on exacerbation rates in patients with non-cystic fibrosis (CF) bronchiectasis. Secondary endpoints included time to first exacerbation, duration of exacerbations, antibiotic use for exacerbations and quality of life (QOL) (St George's Respiratory Questionnaire, SGRQ). METHODS: Patients with non-CF bronchiectasis and a history of chronic excess production of sputum and ≥2 pulmonary exacerbations in the previous 12 months were randomised (1:1) to 52 weeks treatment with inhaled mannitol 400 mg or low-dose mannitol control twice a day. Patients were 18-85 years of age, baseline FEV1 ≥40% and ≤85% predicted and a baseline SGRQ score ≥30. MAIN RESULTS: 461 patients (233 in the mannitol and 228 in the control arm) were treated. Baseline demographics were similar in the two arms. The exacerbation rate was not significantly reduced on mannitol (rate ratio 0.92, p=0.31). However, time to first exacerbation was increased on mannitol (HR 0.78, p=0.022). SGRQ score was improved on mannitol compared with low-dose mannitol control (-2.4 units, p=0.046). Adverse events were similar between groups. CONCLUSIONS: Mannitol 400 mg inhaled twice daily for 12 months in patients with clinically significant bronchiectasis did not significantly reduce exacerbation rates. There were statistically significant improvements in time to first exacerbation and QOL. Mannitol therapy was safe and well tolerated. TRIAL REGISTRATION NUMBER: NCT00669331.

The expanding armamentarium of drugs to aid sputum clearance: how should they be used to optimize care?

PURPOSE OF REVIEW: This review examines the evidence for use of agents that improve sputum clearance in cystic fibrosis. RECENT FINDINGS: The basic defect in cystic fibrosis causes abnormal airway surface liquid leading to mucus plugging and subsequent infection and inflammation in the airways. Agents that improve clearance of secretions should improve lung function, reduce infective exacerbations and may enhance survival. There are two main varieties of mucoactive therapy, namely mucolytic therapy, which reduces viscosity in order to improve clearance, and hyperosmolar therapy, which increases the airway surface liquid volume and increases mucociliary clearance. The development of mannitol as a hyperosmolar agent in dry powder form has heightened the debate regarding the optimal approach to sputum clearance. The evidence for use of individual agents is discussed, as well as a practical approach to combining therapies. SUMMARY: Dornase alfa, a mucolytic agent, and hypertonic saline and mannitol, both hyperosmolar agents, have all been shown to benefit patients with cystic fibrosis. The optimal combination of therapies has not been identified, but a combination of a hyperosmolar agent combined with a mucolytic provides the most logical approach to improving lung function and reducing exacerbations.

Personalised medicine in cystic fibrosis must be made affordable.

The recent introduction of mutation specific therapy to a small group of patients with Cystic Fibrosis has created the debate about the affordability of personalised medicine. I would argue strongly that the NHS must find a way to make revolutionary mutation specific therapies available to patients and explore the routes that all parties must explore to facilitate this. A process which engages industry, providers and patients will provide the best long term answers.

Inhaled interventions in cystic fibrosis: mucoactive and antibiotic therapies.

Treatment of cystic fibrosis lung disease has developed from an understanding of the abnormal airway surface liquid resulting from a lack of function of the cystic fibrosis transmembrane regulator protein. Mucus plugging resulting in infection and inflammation leads to airway wall destruction and bronchiectasis. Inhaled therapies have formed the backbone of treatments. In combination with antibiotics delivered direct to the airway, mucoactive drugs, including mucolytics and hyperosmolar agents, are utilised to improve mucociliary clearance to reduce infection and inflammation. Until recently, airway therapies were delivered as nebulisers, but we have now entered the era of dry powder inhalers for treatment of cystic fibrosis lung disease. The theory and practice of these therapies are discussed in this review.

Prevalence of nontuberculous mycobacteria in cystic fibrosis clinics, United Kingdom, 2009.

Incidence of pulmonary infection with nontuberculous mycobacteria (NTM) is increasing among persons with cystic fibrosis (CF). We assessed prevalence and management in CF centers in the United Kingdom and found 5.0% of 3,805 adults and 3.3% of 3,317 children had recently been diagnosed with NTM. Of those, 44% of adults and 47% of children received treatment.