Elective versus symptomatic antibiotic treatment in cystic fibrosis patients with chronic Pseudomonas infection of the lungs

Antimicrobial Strategies for Cystic Fibrosis

Lung infection is the leading cause of death in cystic fibrosis (CF), and antimicrobial therapies are the backbone of infection management. While many different strategies may be applied, rigorous microbiological surveillance, intensive eradication therapy, and long-term maintenance therapy based on inhaled antibiotics may be considered the main strategy for infection control in individuals with CF. While most of the existing evidence is based on infection with Pseudomonas aeruginosa, other important pathogens causing lung inflammation and deterioration exist and should be treated despite the evidence gap. In this chapter, we describe the approaches to the antimicrobial treatment of the most important pathogens in CF and the evidence behind.

The Elusive Role of Airway Infection in Cystic Fibrosis Exacerbation

Cystic fibrosis (CF) pulmonary exacerbations (PEx) are clinical events that commonly result in increased treatment burden, decreased quality of life, and accelerated lung disease progression. CF PEx have historically been approached as though dealing with acute infections, and antibiotic treatments have been associated with improved outcomes. In this review, we discuss data supporting a causal role of CF airway infection in PEx as well studies that highlight our knowledge gaps in regard to PEx definitions, pathophysiology, and optimal treatment approaches. In the era of highly effective cystic fibrosis transmembrane conductance regulator modulator therapy, and the continually increasing health and longevity of persons with CF, a better understanding of PEx and further optimization of PEx antibiotic treatment approaches are needed.

Gaps in the evidence for treatment decisions in cystic fibrosis: a systematic review

INTRODUCTION

Cystic fibrosis (CF) is a multisystem disorder. Treatment is complex and evidence for treatment decisions may be absent. Characterising gaps in the research evidence will highlight treatment uncertainties and help prioritise research questions. We systematically identified the evidence gaps for treatment decisions in CF.

METHODS

We searched for systematic reviews and guidelines on treatment interventions in CF. Two researchers identified eligible reviews with arbitration from a third. Using a structured framework, we extracted and characterised evidence gaps.

RESULTS

There were 73 reviews and 21 guidelines that met our inclusion criteria. From these, we identified 148 evidence gaps across a range of treatment areas. We found 111 evidence gaps through systematic reviews and a further 37 from guidelines. The reason for an evidence gap could only be reliably characterised for systematic reviews. In most cases, there was more than one explanation-most commonly few or no trials (97/111 evidence gaps). Other important factors leading to evidence gaps were small sample size (49/111), inadequate duration of follow-up (38/111) or intervention (37/111) and factors relating to outcomes (35/111). Evidence gaps from both systematic reviews and guidelines fell into the following categories: Respiratory (91); Gastrointestinal (20); PhysiotherapyandExercise (16); Musculoskeletal (6); Endocrine (4); Basic defect of CF (8); Psychosocial (2); Ears, Nose and Throat (1).

CONCLUSIONS

We have compiled an up-to-date list of treatment uncertainties in CF and the reasons for these uncertainties. These can be used as a resource to aid researchers and funders when planning future trials.

PROSPERO REGISTRATION NUMBER

Pre-results; CRD42015030111.

Daily spirometry in an acute exacerbation of adult cystic fibrosis patients

To help answer the question of length of intravenous antibiotics during an acute exacerbation of cystic fibrosis (CF), we had subjects to follow daily home spirometry while on intravenous antibiotics. CF patients, 18 and older, with an acute exacerbation requiring intravenous antibiotics had a daily FEV1. The average time to a 10% increase over their initial sick FEV1 was calculated, as well as the time to a new baseline. A total of 25 subjects completed the study. Ten of the 25 subjects did not have a sustainable 10% increase in FEV1. Of the 15 subjects with a sustainable 10% increase in FEV1, it took 5.2 days (±4.5) after day 1, while a new baseline was achieved on average at 6.6 days (±4.8) after day 1. Given the wide range of time to a 10% improvement and new baseline, it is recommended there should be flexibility in length of intravenous antibiotics in CF, not by a preset number.

Do cystic fibrosis centres with the lowest FEV1 still use the least amount of intravenous antibiotics? A registry-based comparison of intravenous antibiotic use among adult CF centres in the UK

BACKGROUND

The Epidemiologic Study of Cystic Fibrosis using 1995-1996 and 2003-2005 data found that CF centres with lowest FEV₁ tended to use fewer intravenous antibiotics. We repeated the analyses using 2013-2014 UK CF registry data to determine if this was still the case.

METHODS

Analysing data for 2013 and 2014 separately, 28 adult CF centres were ranked according to median % age-adjusted FEV₁. The top 7 centres were placed in the 'upper quarter' (best FEV₁), the bottom 7 centres in 'lower quarter' (lowest FEV₁), and the rest in 'middle half'. IV use was stratified according to %FEV₁, then compared between the three groups.

RESULTS

Centres in the 'upper quarter' and 'middle half' used significantly more IV antibiotics compared to centres in the 'lower quarter' (van Elteren test P-value<0.001). Regression analyses showed that people with CF attending centres in the 'upper quarter' or 'middle half' are 30-50% more likely to receive at least one IV course per year compared to people attending centres in the 'lower quarter'.

CONCLUSIONS

CF centres with lowest FEV₁ are still distinguished by lower use of intravenous antibiotics.

Lumacaftor/ivacaftor, a novel agent for the treatment of cystic fibrosis patients who are homozygous for the F580del CFTR mutation

INTRODUCTION

Cystic Fibrosis (CF) is an autosomal recessive disease affecting up to 90,000 people worldwide. Approximately 73% of patients are homozygous for the F508del cystic fibrosis transmembrane conductance regulator [CFTR] mutation. Traditionally treatment has only included supportive care. Therefore, there is a need for safe and effective novel therapies targeting the underlying molecular defects seen with CF. Areas covered: In 2016, the Food and Drug Administration and the European Commission approved LUM/IVA (Orkambi), a CFTR modulator that includes both a CFTR corrector and potentiator, for CF patients homozygous for the F508del CFTR mutation. This article reviews the pharmacologic features, clinical efficacy, and safety of LUM/IVA and summarize the available pre-clinical and clinical data of LUM/IVA use. Expert commentary: LUM/IVA showed modest, but significant improvements from baseline in percent predicted FEV₁ (ppFEV₁) as well as a reduction in pulmonary exacerbations by 35% It was shown to be safe for short- and long-term use. Currently, LUM/IVA is the only oral agent in its class available and represents a milestone the development of therapies for the management of CF. Nonetheless, pharmacoeconomic data are necessary to justify its high cost before is use becomes standard of care.

Intravenous antibiotics for pulmonary exacerbations in people with cystic fibrosis

BACKGROUND

Cystic fibrosis is a multi-system disease characterised by the production of thick secretions causing recurrent pulmonary infection, often with unusual bacteria. Intravenous antibiotics are commonly used in the treatment of acute deteriorations in symptoms (pulmonary exacerbations); however, recently the assumption that exacerbations are due to increases in bacterial burden has been questioned.

OBJECTIVES

To establish if intravenous antibiotics for the treatment of pulmonary exacerbations in people with cystic fibrosis improve short- and long-term clinical outcomes.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews and ongoing trials registers.Date of last search of Cochrane trials register: 27 July 2015.

SELECTION CRITERIA

Randomised controlled trials and the first treatment cycle of cross-over studies comparing intravenous antibiotics (given alone or in an antibiotic combination) with placebo, inhaled or oral antibiotics for people with cystic fibrosis experiencing a pulmonary exacerbation.

DATA COLLECTION AND ANALYSIS

The authors assessed studies for eligibility and risk of bias and extracted data.

MAIN RESULTS

We included 40 studies involving 1717 participants. The quality of the included studies was largely poor and, with a few exceptions, these comprised of mainly small, inadequately reported studies.When comparing treatment with a single antibiotic to a combined antibiotic regimen, those participants receiving a combination of antibiotics experienced a greater improvement in lung function when considered as a whole group across a number of different measurements of lung function, but with very low quality evidence. When limited to the four placebo-controlled studies (n = 214), no difference was observed, again with very low quality evidence. With regard to the review's remaining primary outcomes, there was no effect upon time to next exacerbation and no studies in any comparison reported on quality of life. There were no effects on the secondary outcomes weight or adverse effects. When comparing specific antibiotic combinations there were no significant differences between groups on any measure. In the comparisons between intravenous and nebulised antibiotic or oral antibiotic (low quality evidence), there were no significant differences between groups on any measure. No studies in any comparison reported on quality of life.

AUTHORS' CONCLUSIONS

The quality of evidence comparing intravenous antibiotics with placebo is poor. No specific antibiotic combination can be considered to be superior to any other, and neither is there evidence showing that the intravenous route is superior to the inhaled or oral routes. There remains a need to understand host-bacteria interactions and in particular to understand why many people fail to fully respond to treatment.

Tobramycin inhalation powder: an efficient and efficacious therapy for the treatment of Pseudomonas aeruginosa infection in cystic fibrosis

Inhaled antipseudomonal therapies are critical components in the management of cystic fibrosis (CF) and have significantly contributed to improved patient outcomes. Dry powder inhaler technologies represent a significant advance in drug delivery, alleviating treatment burden and potentially improving adherence associated with traditional CF nebulized therapies. Tobramycin inhalation powder (TIP) uses PulmoSphere® technology for very efficient drug delivery into the lower airways. In placebo-controlled and comparative studies with traditional tobramycin formulations, TIP is equally efficacious and is associated with increased patient convenience and satisfaction. TIP has been recommended in the 2013 CF Foundation and the 2014 European guidelines as a therapy in CF for the maintenance of lung health. Going forward, TIP may offer a therapeutic advantage over traditional formulations of tobramycin as recent prospective ‘real world’ studies of TIP have demonstrated high patient tolerance and improved adherence compared with traditional formulations.

Use of lung clearance index to assess the response to intravenous treatment in cystic fibrosis

BACKGROUND

Progressive lung disease is the main cause of clinical deterioration and mortality in cystic fibrosis (CF) patients. Being able to assess the effectiveness of interventions is very significant.

OBJECTIVES

To assess the response to intravenous (IV) treatment among CF patients, using forced expired volume in 1(st) second (FEV1) and Lung Clearance Index (LCI) as outcome measures and to compare the effect of IV treatment on lung function and LCI between CF children being treated on a regular basis, or in case of a pulmonary exacerbation.

SUBJECTS AND METHODS

Thirty-two CF patients (15 males) with mean age 9.90 (range: 2-23) years, performed spirometry and multiple breath washout (MBW) before and one month after IV antibiotic treatment. Nineteen patients received a course of elective treatment (group A) and 13 received IV antibiotic regimens for an acute exacerbation (group B).

RESULTS

Statistically significant differences after treatment were seen in LCI (p≤0.001), and Forced Expiratory Flow (FEF) z-scores (p<0.05). FEV1 did not change significantly after drug intervention. Dividing patients into two groups, only LCI showed significant change (p<0.05), when treatment was administered on a regular basis. Patients being treated for an acute pulmonary exacerbation showed significant improvement in most of the lung function parameters: LCI (p=0.0001), FEV1% (p=0.05), FEV1 z-score (p=0.033) and FEF25-75 (p=0.046). The mean LCI difference was significantly greater in group B compared to group A (p=0.001).

CONCLUSION

LCI is more sensitive marker than FEV1 to assess the effect of IV antibiotic treatment among CF children. IV antibiotics are more effective on lung function parameters, when they are administered for an acute exacerbation, than when they are given on a regular basis. Hippokratia 2015, 19 (1): 47-52.

Candidate markers associated with the probability of future pulmonary exacerbations in cystic fibrosis patients

Introduction

Pulmonary exacerbations (PEs) cause significant morbidity and can severely impact disease progression in cystic fibrosis (CF) lung disease, especially in patients who suffer from recurrent PEs. The assessments able to predict a future PE or a recurrent PE are limited. We hypothesized that combining clinical, molecular and patient reported data could identify patients who are at risk of PE.

Methods

We prospectively followed a cohort of 53 adult CF patients for 24 months. Baseline values for spirometry, clinical status using the Matouk Disease Score, quality of life (QOL), inflammatory markers (C-reactive protein (CRP), interleukins (IL)-1β, -6, -8, -10, macrophage inflammatory protein (MIP)-1β, tumor necrosis factor (TNF) and vascular endothelial growth factor (VEGF)), polyunsaturated fatty acids and lipid peroxidation in blood plasma were collected for all patients during periods of stable disease, and patients were monitored for PE requiring PO/IV antibiotic treatment. Additionally, we closely followed 13 patients during PEs collecting longitudinal data on changes in markers from baseline values. We assessed whether any markers were predictors of future PE at baseline and after antibiotic treatment.

Results

Out of 53 patients, 37 experienced PEs during our study period. At baseline, we found that low lung function, clinical scoring and QOL values were associated with increased risk of PE events. PEs were associated with increased inflammatory markers at Day 1, and these biomarkers improved with treatment. The imbalance in arachidonic acid and docosahexaenoic acid levels improved with treatment which coincided with reductions in lipid peroxidation. High levels of inflammatory markers CRP and IL-8 were associated with an early re-exacerbation.

Conclusion

Our results demonstrate that worse clinical and QOL assessments during stable disease are potential markers associated with a higher risk of future PEs, while higher levels of inflammatory markers at the end of antibiotic treatment may be associated with early re-exacerbation.

Tobramycin Inhalation Powder (TIP): An Efficient Treatment Strategy for the Management of Chronic Pseudomonas Aeruginosa Infection in Cystic Fibrosis

Repeated bouts of acute and chronic lung infections are responsible for progressive pulmonary function decline in individuals with cystic fibrosis (CF), ultimately leading to respiratory failure and death. Pseudomonas aeruginosa is the archetypical CF pathogen, causes chronic infection in 70% of individuals, and is associated with an accelerated clinical decline. The management of P. aeruginosa in CF has been revolutionized with the development and widespread use of inhaled antibiotics. Aerosol delivery of antimicrobial compounds in CF enables extremely high concentrations of antibiotics to be reached directly at the site of infection potentially overcoming adaptive resistance and avoiding the potential for cumulative systemic toxicities. Tobramycin inhalation powder (TIP) represents the first dry powder inhaled (DPI) antibiotic available for use in CF. DPIs are notable for a markedly reduced time for administration, ease of portability, and increased compliance. TIP has been developed as a therapeutic alternative to tobramycin inhalation solution (TIS), the standard of care for the past 20 years within CF. Relative to TIS 300 mg nebulized twice daily in on-and-off cycles of 28 days duration, TIP 112 mg twice daily via the T-326 inhaler administered on the same schedule is associated with marked time savings, increased patient satisfaction, and comparable clinical end points. TIP represents an innovative treatment strategy for those individuals with CF and holds the promise of increased patient compliance and thus the potential for improved clinical outcomes.

Current dilemmas in antimicrobial therapy in cystic fibrosis

The majority of cystic fibrosis (CF)-related morbidity and mortality is caused by pulmonary damage due to recurrent and chronic infections. Considerable improvements in the survival of individuals with CF have been achieved in recent decades, some of which may be due to better management of common pathogens such as Staphylococcus aureus and Pseudomonas aeruginosa. While the search continues for the optimal approach for prophylaxis, eradication and maintenance treatment of infections, there are several unanswered questions, posing dilemmas related to various therapeutic choices. Microbes pose additional challenges by adapting to CF lungs and developing treatment resistance. Several new, highly antimicrobial-resistant pathogens have emerged. Their pathogenic role in the progression of CF lung disease is not yet clear and effective treatment approaches have not been defined. There is an urgent need for well-designed comparative clinical trials of new antibiotic strategies.

Eight-weekly intravenous antibiotics is beneficial in severe bronchiectasis

AIM

The aim of our study was to assess the impact of 8-weekly intravenous (IV) antibiotics on exacerbation frequency and health-related quality of life in bronchiectasis.

METHODS

Patients were recruited prospectively from June 2008 to December 2010. Patients with recurrent exacerbations (five or more exacerbations per year) and subjectively reporting ill health between antibiotic courses were recruited. Eight-weekly IV antibiotics (for 14 days) were initiated. Patients were followed up for 1 year. Main outcome was reduction in exacerbation frequency and improvement in health-related quality of life (HRQoL) at 1 year after starting intravenous antibiotic therapy. Other outcomes recorded were forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC), incremental shuttle walk test (ISWT), 24-h sputum volume, sputum microbiology, body mass index (BMI), markers of inflammation--white cell count (WCC), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR).

RESULTS

In total, 19 patients were recruited. Mean age was 64.1 years and 52.6% were female. With 8-weekly antibiotics, there was a significant reduction in the number of exacerbations [mean (SE): 9.3 (0.5) in the year before vs. 8.0 (0.4) in the year after; P = 0.02]. In 63.2%, Leicester Cough Questionnaire (LCQ) improved by ≥1.3 U (P = 0.006)] and in 42.1% St. George's Respiratory Questionnaire (SGRQ) improved by ≥4 U (P = 0.03). Exercise capacity increased by 58.7 m (P = 0.004). There was no improvement in the other end points.

CONCLUSION

Treatment with 8-weekly intravenous antibiotics in severe bronchiectasis reduced exacerbation frequency and improved exercise tolerance and health-related quality of life.

Fluoroquinolones in the treatment of bronchopulmonary disease in cystic fibrosis

Fluoroquinolones are commonly used to treat lung infections in patients with cystic fibrosis. These patients are susceptible to lung infection with common bacteria such as Staphylococcus aureus and Haemophilus influenzae, but are also prone to infection by opportunistic bacteria, including Pseudomonas aeruginosa. The good oral bioavailability and broad antimicrobial spectrum of activity, including antipseudomonal properties, make this class of antimicrobial attractive. We review the evidence assessing the use of fluoroquinolones in the context of preventing and eradicating early lung infection and in managing chronic lung infection and pulmonary exacerbations. The safety of fluoroquinolones and the use of newer agents in the class are also discussed.

Elective versus symptomatic intravenous antibiotic therapy for cystic fibrosis

BACKGROUND

Pseudomonas aeruginosa is the commonest micro-organism associated with respiratory infections in cystic fibrosis. Retrospective studies have suggested that using an aggressive policy of intravenous anti-pseudomonal antibiotics at regular intervals, irrespective of symptoms, increases survival.

OBJECTIVES

To determine whether there is evidence that an elective (regular) versus symptomatic intravenous antibiotic regimen is associated with an improvement in clinical status and survival rates in people with cystic fibrosis. To identify any adverse effects associated with the use of elective intravenous antibiotics, including an increase in the development of resistant organisms.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches, handsearches of relevant journals and abstract books of conference proceedings.Date of the most recent search of the Group's Cystic Fibrosis Trials Register: 15 March 2012.

SELECTION CRITERIA

All randomised or quasi-randomised controlled trials describing the use of elective compared with symptomatic intravenous antibiotic policies for any duration or dose regimen. Elective versus symptomatic intravenous antibiotic regimens against any organisms were considered. People with cystic fibrosis of any age or disease severity were included.

DATA COLLECTION AND ANALYSIS

Both authors independently assessed trial eligibility and quality; both extracted the data.

MAIN RESULTS

Searches identified four studies. Two studies reporting results from a total of 79 participants were included in the review. Differences in study design and objectives meant that data could not be pooled for meta-analysis. Neither study demonstrated significant differences in outcome measures between intervention and comparison groups.

AUTHORS' CONCLUSIONS

Studies are insufficient to identify conclusive evidence favouring a policy of elective intravenous antibiotic administration, despite its widespread use, neither are the potential risks adequately evaluated. The results should be viewed with caution, as participant numbers are small. Clearly there is a need for a well-designed, adequately-powered, multicentred randomised controlled trial to evaluate these issues.

Tobramycin administered by the TOBI(®) Podhaler(®) for persons with cystic fibrosis: a review

From its introduction, the antibiotic tobramycin has been an important tool in the management of persons with cystic fibrosis (CF) and chronic Pseudomonas aeruginosa lung infections. Initially an intravenous rescue treatment for pulmonary exacerbations, tobramycin delivered by inhalation has become a mainstay of chronic suppressive CF infection management. Platforms for tobramycin aerosol delivery have steadily improved, with increased lung deposition complimented by decreased device complexities, loaded tobramycin doses, delivery times, and treatment burdens. Most recently, a unique tobramycin inhalation powder (TIP) formulation with a portable delivery system, the TOBI^® Podhaler^® (Novartis AG, Basel, Switzerland) has been developed and approved in Europe, Canada, and Chile. Four capsules, each containing 28 mg of TIP are successively pierced and inhaled via the T-326 Dry Powder Inhaler Device (Novartis AG, Basel, Switzerland). No external power source is required to deliver an efficacious tobramycin dose in minutes. By comparison, tobramycin inhalation solution (TIS) (TOBI^®; Novartis), is delivered by LC^® Plus (PARI Respiratory Equipment Inc, Midlothian, VA) jet nebulizer powered by an air compressor over 15–20 minutes. Comparative pharmacokinetics, safety, and efficacy studies of TIS and TIP in CF subjects with P. aeruginosa ≥ 6 years old demonstrate that: tobramycin lung deposition with 112 mg TIP is comparable to that attained with 300 mg TIS, TIP is more effective than placebo and not inferior to TIS with respect to pulmonary function benefit, and TIP has significantly faster treatment times and achieves higher patient satisfaction than TIS. TIP is associated with an increased frequency of mild to moderate local adverse events (cough, dysphonia, and dysgeusia) compared with TIS, however, these become less frequent as subjects gain TIP experience. These results suggest that the TOBI Podhaler may better meet the needs of many CF patients and families by reducing treatment time and complexity and improving patient satisfaction compared with TIS.

Aztreonam lysine: a novel inhalational antibiotic for cystic fibrosis

Acquisition of Pseudomonas aeruginosa, the most prevalent organism isolated from cystic fibrosis (CF) airways, is associated with an accelerated clinical deterioration and reduced survival. Strategies to chronically suppress P. aeruginosa infections in individuals with CF have evolved over the last four decades and now largely focus on regular administration of aerosolized antibiotics. Aztreonam lysine (AZLI; Cayston, Gilead Pharmaceuticals [Foster City, CA, USA]), a novel formulation of the monobactam aztreonam suitable for aerosol delivery has recently been developed. AZLI is administered as 75 mg three-times daily for 28 days in 'on/off' cycles using the Altera/eFlow electronic nebulizer (PARI Innovative Manufacturers [Midlothian, VA, USA]). In individuals with CF chronically infected with P. aeruginosa, AZLI improved healthcare-associated quality-of-life scores, pulmonary function and weight, prolonged time to requirement of antibacterial therapy for symptoms of pulmonary exacerbation and reduced P. aeruginosa sputum burdens. These outcomes were durable over 18 months of cycled use. AZLI has been demonstrated to be safe and effective, and expands available chronic maintenance therapies in CF.

Antibiotic therapy against Pseudomonas aeruginosa in cystic fibrosis

Antibiotic strategies against Pseudomonas aeruginosa infection in cystic fibrosis (CF) patients should consider the natural history of the P. aeruginosa infection, ranging from the first isolation of the germ in the airways to isolation at every microbiological culture, and the patient's clinical condition. Antibiotic treatment against P. aeruginosa given at the time of first isolation may prevent or delay chronic infection. The period of intermittent colonization can be considered the time before the development of mucoid P. aeruginosa phenotype. The optimal treatment strategy in this stage remains unclear in terms of agents used and duration of treatment. To treat acute exacerbation, the authors suggest using intravenous administration of two different classes of antibiotics. Maintenance antibiotics are administered to slow the decline in pulmonary function for P. aeruginosa chronic infection. The meaning of maintenance therapy has changed over time, beginning from intravenous quarterly anti-Pseudomonas antibiotics, irrespective of symptoms, to other strategies such as oral macrolides, ciprofloxacin or inhaled antibiotics (tobramycin and colistin). Aerosol delivery can provide a high concentration at the desired site with minimal absorption and therefore low risk of toxicity. There is scientific evidence that antibiotics are clinically effective in CF patients. Antibiotic selection should be based on periodic isolation and identification of pathogens and antimicrobial susceptibility.

Exacerbations in cystic fibrosis: 2 . prevention

The life span of people with cystic fibrosis (CF) has increased dramatically over the past 50 years. Many factors have contributed to this improvement. Respiratory exacerbations of CF lung disease are associated with the need for hospitalisation and antibiotic treatment, reduction in the quality of life, fragmented sleep and mortality. A number of preventive treatment strategies have been developed to reduce the frequency and severity of respiratory exacerbations in CF including mucolytic agents, physiotherapy and exercise, antibiotics, nutritional strategies, anti-inflammatory treatments and vaccinations against common respiratory pathogens. The evidence for each of these treatments and their potential impact is discussed.

More Than 10 Years' Continuous Oral Treatment with Specific Immunoglobulin Y for the Prevention ofPseudomonas aeruginosaInfections: A Case Report

Immunotherapy with specific antibodies is an alternative to antibiotics for the prevention of infections in humans and animals. We have used orally administered immunoglobulin Y (IgY) preparations, purified from eggs of hens immunized with Pseudomonas aeruginosa bacteria, to prevent pulmonary P. aeruginosa infections in a group of patients with cystic fibrosis (CF). Respiratory infections are major problems for CF patients because of the thick mucus in the airways, and chronic P. aeruginosa lung infections occur in virtually all CF patients and cause morbidity and mortality. The IgY-treated group had only 2.5 P. aeruginosa-positive sputum cultures per 100 months, and none of the IgY-treated patients became chronically colonized with P. aeruginosa. In the control group, 13.7 of the cultures per 100 months were positive for P. aeruginosa, and 24% of patients became chronically colonized with P. aeruginosa. The first enrolled patient in this study has now been treated continuously for more than 10 years. During the first 8 years she only had four P. aeruginosa-positive cultures. After 8 years she became chronically infected, but still after 10 years the bacteria have not turned mucoid. No negative side effects of IgY treatment have been noted during these 10 years. To our knowledge this is the longest treatment with specific yolk antibodies for therapeutic purposes.

Clinical trials in cystic fibrosis

In patients with cystic fibrosis (CF), clinical trials are of paramount importance. Here, the current status of drug development in CF is discussed and future directions highlighted. Methods for pre-clinical testing of drugs with potential activity in CF patients including relevant animal models are described. Study design options for phase II and phase III studies involving CF patients are provided, including required patient numbers, safety issues and surrogate end point parameters for drugs, tested for different disease manifestations. Finally, regulatory issues for licensing new therapies for CF patients are discussed, including new directives of the European Union and the structure of a European clinical trial network for clinical studies involving CF patients is proposed.

[Efficiency of the home intravenous antibiotics treatment in cystic fibrosis]

BACKGROUND AND OBJECTIVE

The objective of our study was to determine the costs saving with the implementing of a home intravenous antibiotic treatment (HIVAT) program for patients with cystic fibrosis and to compare it with the conventional system (inpatient).

PATIENTS AND METHOD

Consecutive patients in an adults cystic fibrosis unit were selected who received some days of HIVAT, between January 2002 and December 2004. For the analysis of costs saving of the HIVAT, we used the difference between the total costs of the avoided stay days and the costs generated by the domiciliary therapy (drugs, expendable equipment) and by the ambulatory medicine unit in case the patients were not hospitalized. All patients received a therapy with an intravenous antibiotic for a minimum of 14 days. All these data were provided by the accounting service of the hospital with the aid management Clinical Financier Program (GECLIF).

RESULTS

22 patients with cystic fibrosis needed 85 intravenous antibiotics treatments during the 3 years of the study, of which: 43 cycles were completely domiciliary, 14 inpatient and 28 were combined (hospital and home). The 71 cycles of HIVAT originated 909 days at home, with an average (standard deviation) of 12.80 (4.18) days and 43 treatments in ambulatory medicine unit. The home antibiotic treatments that originated greater cost (3,964.34 Euro) was meropenem (1 g/6 h) i.v. with linezolid (600 mg/12 h) via oral combination during 14 days, and in second place the association of ceftazidime, tobramycine and linezolid, whose cost in cycle of 14 days was of 2464.84 Euro. The average saving cost in the 3 years of study was of 2,647.29 Euro by each cycle of HIVAT and global 197,689.78 Euro.

CONCLUSIONS

HIVAT obtained important sanitary costs saving and this was greater every year, not due to the increase of days at home, but due to the rising cost per day of hospital stays every new year.

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.

Diagnosing and managing infection in CF

Acute and chronic bacterial infections of the lower respiratory tract remain one of the hallmarks of cystic fibrosis lung disease. We here review some of the controversial areas of diagnosing airway infection in CF patients including the use of techniques such as induced sputum and bronchoalveolar lavage. Treatment strategies have evolved over the years and there is ongoing discussion as to whether to treat on the basis of symptoms, positive cultures alone or continuously regardless of clinical and laboratory findings. Prophylactic antibiotic therapy with anti-staphylococcal antibiotics has been linked to a higher incidence of P. aeruginosa infection, but it is still unclear whether this side effect is limited to broader spectrum antibiotics such as cephalosporins. Early antibiotic therapy against P. aeruginosa has become an accepted treatment strategy as it not only delays the onset of chronic infection, but also leads to eradication of the organism in the majority of patients. So far no evidence exists that combination therapy is superior to inhaled therapy alone. In addition, the optimal duration of therapy type of inhaled antibiotic as well as the optimal dose has not been clarified. Studies are currently ongoing to resolve these issues.

Acute renal failure in CF patients chronically infected by the Liverpool epidemic Pseudomonas aeruginosa strain (LES)

Although acute renal failure has been described in children with CF in relation to intravenous aminoglycoside use, there are no reports in the adult CF literature. We describe 8 cases of acute renal failure in adult CF patients, all occurring during the use of intravenous aminoglycosides for the treatment of pulmonary exacerbations with an epidemic multi-resistant Pseudomonas aeruginosa strain. Potential contributory factors are discussed. These cases demonstrate another complication of infection by epidemic Pseudomonas strains in CF, and confirm the need for effective segregation policies to prevent this.

Ventilation Inhomogeneities in Relation to Standard Lung Function in Patients with Cystic Fibrosis

Based on serial lung function measurements performed in 142 children (68 males; 74 females) with cystic fibrosis (CF), prospectively evaluated over an age range of 6 to 20 years, we attempted to determine whether the lung clearance index (LCI) as a measure of ventilation inhomogeneities could be a discriminating factor of disease progression. Annual follow-up lung function measurements featuring FRC determined by whole-body plethysmography and multibreath nitrogen washouts, effective specific airway resistance, flow-volume curves, LCI, and gas exchange characteristics were analyzed by linear mixed-model analysis and Kaplan-Meier statistics. The earliest occurring and strongest factor of progression was the LCI, followed by maximal expiratory flow (MEF(50)) and FRC determined by plethysmography (p < 0.0001). Associations between onset of chronic Pseudomonas aeruginosa infection and CF transmembrane conductance regulator (CFTR) genotype with FEV(1) (p = 0.027) and FVC (p = 0.007) were identified. The study shows that the LCI predicts earlier in life and represented much better functional progression than FEV(1). Moreover, there is no single functional predictor of progression in CF, but aside from risk factors, such as onset of chronic P. aeruginosa infection and genotype, pulmonary hyperinflation, airway obstruction, and ventilation inhomogeneities are important pathophysiologic processes that should be evaluated concomitantly as determinants of lung progression in CF.

Renal impairment in cystic fibrosis patients due to repeated intravenous aminoglycoside use

Although there are reports of cases of acute renal failure occurring in cystic fibrosis (CF) patients, usually in association with the use of nephrotoxic antibiotic therapy, there have been no studies of renal function in this patient group. We hypothesized that long-term use of intravenous (IV) nephrotoxic antibiotics (aminoglycosides and colistin sulphomethate) may contribute to renal disease in CF patients. In a prospective study, we assessed creatinine clearance as an index of renal function with two techniques (24-hr urine collections and the Cockroft-Gault formula) in a group of 80 stable adult CF outpatients chronically infected with Pseudomonas aeruginosa but with no history of preceding renal disease. Using a multiple linear regression model, we evaluated their renal function in terms of their lifetime IV use of aminoglycosides and colistin. Between 31% (Cockroft-Gault formula method) and 42% (24-hr urine collection method) of patients had a creatinine clearance below normal range. Using either method, there was a strong correlation between aminoglycoside use and diminishing renal function (r=- 0.32, P=0.0055), which was potentiated by the coadministration of colistin (r=- 0.42, P <0.0002). However, there was no correlation with colistin when used in combination with other antibiotics alone (r=0.18, P=NS). Repeated IV aminoglycoside use in CF is associated with long-term renal damage. Although this effect is potentiated by colistin, colistin on its own in moderate doses does not appear to be nephrotoxic. IV aminoglycosides should be used cautiously in CF patients, with regular monitoring of renal function.

[Home intravenous antibiotic treatments in cystic fibrosis units of Madrid]

BACKGROUND AND OBJECTIVE

A descriptive study of the home intravenous antibiotic treatment (HIVAT) course in cystic fibrosis (CF) units of Madrid in an 18 month period. Different patient features were recorded, antibiotherapy, intravenous access, complications and their resolutions. We accessed the improvement of the pulmonary function, forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) at the end of the treatment.

PATIENTS AND METHOD

For an 18 months period (January 2002-June 2003) the patients with CF who received HIVAT and fulfilled the previously fixed criteria were included. The next clinic variables were collected: age, sex, bacterial colonization of respiratory tree, pancreatic function and pulmonary function in steady phase, before and after HIAT.

RESULTS

56 patients, 31 male and 25 female, were given 90 courses of HIAT (34 patients received only one course). Mean age was 20.06 (8.07) years. 57.1% of the patients were colonized by Pseudomonas aeruginosa. The most frequently used antibiotics were ceftazidime and tobramycin. Courses of treatment lasted a mean of 4.08 (5.09) days inpatient and 11.89 (4.96) at home. In 87.7% of the course were used the intravenous cannulae, Port-a-cath in 6.7% and Venocath in 7.8%. The intravenous access was replaced, in the 64.4% of the cases, by the nurse of the CF Unit, in the 21.4% in the emergency room of the nearest hospital and in 11.9% in primary care center. Three occasions skin reactions were reported. The parameters of pulmonary function improved significatively after HIVAT.

CONCLUSIONS

The HIVAT is a therapeutic option that, following predetermined inclusion criteria, has a low complication rate and improves pulmonary function.

Antibody response to Pseudomonas aeruginosa in cystic fibrosis patients: a marker of therapeutic success?--A 30-year cohort study of survival in Danish CF patients after onset of chronic P. aeruginosa lung infection

We studied the effects of increasingly intensive treatment regimens on anti-pseudomonal antibody response and survival in five successive cohorts of a total of 157 Danish cystic fibrosis patients after they had acquired chronic P. aeruginosa lung infection. The time periods were 1971-1975 (N = 21), 1976-1980 (N = 64), 1981-1986 (N = 27), 1987-1993 (N = 26), and 1994-2000 (N = 19). During this 30-year period, we introduced elective 2-week courses of chemotherapy every third month in all chronically infected patients, early aggressive treatment with inhalation of colistin and oral ciprofloxacin for 3 months whenever P. aeruginosa was cultured in sputum from noncolonized patients, and inhalation of recombinant human dornase alfa. There was a significant correlation between the calendar year when chronic P. aeruginosa infection was acquired and the subsequent increase in the level of precipitins (P < 0.00001). The median number of precipitins increased by 5 per year in the oldest calendar year cohort, and 1 per year in the youngest. The median age of onset of chronic P. aeruginosa increased from 9.3 years from 1981-1986 to 13.8 years from 1987-2000. Survival after acquisition of chronic P. aeruginosa lung infection improved with time (P = 0.008). Our study shows that CF patients who are treated intensively have lower antibody responses and longer survival after acquisition of chronic P. aeruginosa lung infection.

Oral administration of specific yolk antibodies (IgY) may prevent Pseudomonas aeruginosa infections in patients with cystic fibrosis: a phase I feasibility study

Respiratory infection is the major cause of morbidity and mortality in cystic fibrosis (CF) patients. Chronic Pseudomonas aeruginosa (PA) infections ultimately occur in virtually all patients. It is impossible to eradicate PA when a patient has been chronically colonized. Immunotherapy with specific egg-yolk antibodies (IgY) may be an alternative to antibiotics for the prevention of PA infections. We wanted to determine if treatment with specific IgY can prolong the period between the first and the second PA colonization? And long-term, can the treatment diminish the number of positive PA cultures and postpone the onset of chronic colonization? CF patients gargled daily with an IgY-antibody preparation, purified from eggs of hens immunized with PA bacteria. They were compared to a group of patients who did not gargle with the preparation. Both groups had their first colonization with PA eradicated by antibiotics. The basic treatment was essentially the same in both groups. In the initial study, the period between the first and second colonization with PA was significantly prolonged for the treated vs. the control group (Kaplan-Meier P = 0.015, Breslow test). In the prolonged study, the treated group had only 2.5 sputum cultures positive for PA per 100 months of observation, and none of these patients became chronically colonized with PA. No adverse events were reported. In the control group, 13.7 cultures per 100 months of observation were positive for PA, and 5 (24%) patients became chronically colonized with PA. This feasibility study shows that antipseudomonal IgY has the potential to effectively prevent PA colonization without any severe adverse effects. A phase III study should be initiated.

Development of resistance in Pseudomonas aeruginosa obtained from patients with cystic fibrosis at different times

OBJECTIVE

Determination of the extent of changes in quantitative resistance in Pseudomonas aeruginosa isolates from patients with cystic fibrosis over a period of approximately 2 years.

METHODS

Three hundred and ninety nine isolates of P. aeruginosa collected from 34 pediatric patients in the period between April 1994 and April 1996 were investigated. During the 2 years the children were treated with a combination of a betalactam and an aminoglycoside, approximately every 3 months. In between they received ciprofloxacin orally, when required. The minimal inhibitory concentrations (MICs) of 38 clones of P. aeruginosa defined by different patterns in macrorestriction analysis (pulse field gel electrophoresis, PFGE) were established for 12 antibiotics: gentamicin, amikacin, tobramycin, ciprofloxacin, levofloxacin, moxifloxacin, trovafloxacin, imipenem, meropenem, ceftazidime, cefepime, and piperacillin by means of broth microdilution tests according to DIN 58940.

RESULTS

Twenty-four of the 38 clones developed increased MIC values during the time of observation especially for aminoglycosides and quinolones. Comparatively less affected were ceftazidime, imipenem and meropenem. An association between the number of the intravenous treatment courses and the increase of the MIC values could not be verified.

CONCLUSIONS

A trend towards an increase of the MICs against antipseudomonal agents was observed over a limited period of time. It is necessary to prevent this development possibly by employing suitable combinations of antibiotics and the introduction of new substances.

Cystic fibrosis

Cystic fibrosis is the most common autosomal recessive disorder in white people, with a frequency of about 1 in 2500 livebirths. Discovery of the mutated gene encoding a defective chloride channel in epithelial cells--named cystic fibrosis transmembrane conductance regulator (CFTR)--has improved our understanding of the disorder's pathophysiology and has aided diagnosis, but has shown the disease's complexity. Gene replacement therapy is still far from being used in patients with cystic fibrosis, mostly because of difficulties of targeting the appropriate cells. Life expectancy of patients with the disorder has been greatly increased over past decades because of better notions of symptomatic treatment strategies. Here, we summarise advances in understanding and treatment of cystic fibrosis, focusing on pulmonary disease, which accounts for most morbidity and deaths.

Recent advances in cystic fibrosis

The median life expectancy for cystic fibrosis is now over 30 years, and it is projected that in newborn infants it will become more than 40 years. The identification of the cystic fibrosis gene and its product, cystic fibrosis transmembrane conductance regulator (CFTR), has widened the spectrum of the disease from the classical case of the infant with cystic fibrosis to the elderly childless man with unexplained bronchiectasis. There is increasing evidence of the advantages of newborn screening for cystic fibrosis and subsequent specialist care. Management concentrates on optimising nutritional status and preventing lung infection and inflammation.

Elective versus symptomatic intravenous antibiotic therapy for cystic fibrosis

BACKGROUND

Pseudomonas aeruginosa is the commonest micro-organism associated with respiratory infections in cystic fibrosis. Retrospective studies have suggested that survival is increased by using an aggressive policy of intravenous antipseudomonal antibiotics at regular intervals, irrespective of symptoms.

OBJECTIVES

To determine whether there is evidence that an elective (regular) versus symptomatic intravenous antibiotic regime is associated with an improvement in clinical status and survival rates in patients with cystic fibrosis. To identify any adverse effects associated with the use of elective intravenous antibiotics, including an increase in the development of resistant organisms.

SEARCH STRATEGY

The Cochrane Cystic Fibrosis and Genetics Disorders Group Specialist Trials Register was used. This comprises references identified from comprehensive electronic database searches, hand searching relevant journals and abstracts from conference proceedings. Date of the most recent search of the Group's specialised register: October 2000.

SELECTION CRITERIA

All randomised or pseudo-randomised controlled trials describing the use of elective compared with symptomatic intravenous antibiotic policies for any duration or dose regimen. Elective versus symptomatic intravenous antibiotic regimes against any organisms were considered. Patients with cystic fibrosis were of any age or disease severity.

DATA COLLECTION AND ANALYSIS

Trials were independently assessed for inclusion criteria, methodological quality and data extraction by the two reviewers.

MAIN RESULTS

Three trials were identified by the initial search. Two trials reporting results from a total of 79 patients were included in the review. Differences in study design and objectives meant that data could not be pooled for meta-analysis. Neither trial demonstrated significant differences in outcome measures between intervention and comparison groups.

REVIEWER'S CONCLUSIONS

Studies are insufficient to identify conclusive evidence favouring a policy of elective intravenous antibiotic administration, despite its widespread use. Neither are the potential risks adequately evaluated. The results should be viewed with caution as patient numbers are small. Clearly there is a need for a well-designed, adequately powered, multi-centred randomised controlled trial to evaluate these issues.

Prospects for the prevention and control of pseudomonal infection in children with cystic fibrosis

Most patients with cystic fibrosis (CF) experience recurrent and chronic endobronchial Pseudomonas aeruginosa infections. It is possible to prevent or delay the onset of these chronic infections in most patients with CF by eliminating cross-infection and by early aggressive antibiotic treatment of the first positive sputum culture and of subsequent intermittent colonisation. Lung tissue damage is caused by activation of the immunologically specific inflammatory defence mechanisms of the lungs, which are initiated by the antibody response and dominated by polymorphonuclear neutrophil leucocytes and their proteolytic and oxidative products. This inflammation induces a phenotypic shift from nonmucoid to mucoid, alginate-producing phenotypes of P. aeruginosa which then grow, endobronchially, as a biofilm. Such biofilms are impossible to eradicate with antibiotics. By using chronic suppressive antibiotic maintenance therapy and anti-inflammatory drugs it is however, possible to maintain the lung function of these patients for a number of years.