Short-term and long-term effects of albuterol aerosol therapy in cystic fibrosis: a preliminary report

Effect of Salbutamol on Lung Ventilation in Children with Cystic Fibrosis: Comprehensive Assessment Using Spirometry, Multiple-Breath Washout, and Functional Lung Magnetic Resonance Imaging

BACKGROUND

Inhalation therapy is one of the cornerstones of the daily treatment regimen in patients with cystic fibrosis (CF). Recommendations regarding the addition of bronchodilators, especially salbutamol are conflicting due to the lack of evidence. New diagnostic measures such as multiple-breath washout (<underline>MBW)</underline> and functional magnetic resonance imaging (MRI) have the potential to reveal new insights into bronchodilator effects in patients with CF.

OBJECTIVE

The objective of the study was to comprehensively assess the functional response to nebulized inhalation with salbutamol in children with CF.

METHODS

Thirty children aged 6-18 years with stable CF performed pulmonary function tests, MBW, and matrix pencil-MRI before and after standardized nebulized inhalation of salbutamol.

RESULTS

Lung clearance index decreased (improved) by -0.24 turnover (95% confidence interval [CI]: -0.53 to 0.06; p = 0.111). Percentage of the lung volume with impaired fractional ventilation and relative perfusion decreased (improved) by -0.79% (CI: -1.99 to 0.42; p = 0.194) and -1.31% (CI: -2.28 to -0.35; p = 0.009), respectively. Forced expiratory volume (FEV1) increased (improved) by 0.41 z-score (CI: 0.24-0.58; p < 0.0001). We could not identify specific clinical factors associated with a more pronounced effect of salbutamol.

CONCLUSIONS

There is a positive short-term effect of bronchodilator inhalation on FEV1 in patients with CF, which is independent of ventilation inhomogeneity. Heterogeneous response between patients suggests that for prediction of a therapeutic effect this should be tested by spirometry in every patient individually.

WITHDRAWN: Inhaled bronchodilators for cystic fibrosis

This review has been withdrawn because it has been split into the following reviews: 'Long‐acting inhaled bronchodilators for cystic fibrosis' and 'Short‐acting inhaled bronchodilators for cystic fibrosis'.

The editorial group responsible for this previously published document have withdrawn it from publication.

Diurnal and twenty-four hour patterning of human diseases: cardiac, vascular, and respiratory diseases, conditions, and syndromes

Various medical conditions, disorders, and syndromes exhibit predictable-in-time diurnal and 24 h patterning in the signs, symptoms, and grave nonfatal and fatal events, e.g., respiratory ones of viral and allergic rhinorrhea, reversible (asthma) and non-reversible (bronchitis and emphysema) chronic obstructive pulmonary disease, cystic fibrosis, high altitude pulmonary edema, and decompression sickness; cardiac ones of atrial premature beats and tachycardia, paroxysmal atrial fibrillation, 3rd degree atrial-ventricular block, paroxysmal supraventricular tachycardia, ventricular premature beats, ventricular tachyarrhythmia, symptomatic and non-symptomatic angina pectoris, Prinzmetal vasospastic variant angina, acute (non-fatal and fatal) incidents of myocardial infarction, sudden cardiac arrest, in-bed sudden death syndrome of type-1 diabetes, acute cardiogenic pulmonary edema, and heart failure; vascular and circulatory system ones of hypertension, acute orthostatic postprandial, micturition, and defecation hypotension/syncope, intermittent claudication, venous insufficiency, standing occupation leg edema, arterial and venous branch occlusion of the eye, menopausal hot flash, sickle cell syndrome, abdominal, aortic, and thoracic dissections, pulmonary thromboembolism, and deep venous thrombosis, and cerebrovascular transient ischemic attack and hemorrhagic and ischemic stroke. Knowledge of these temporal patterns not only helps guide patient care but research of their underlying endogenous mechanisms, i.e., circadian and others, and external triggers plus informs the development and application of effective chronopreventive and chronotherapeutic strategies.

Inhaled hypertonic saline as a therapy for cystic fibrosis

PURPOSE OF REVIEW

The beneficial effect of a short course of nebulized hypertonic saline on lung function for people with cystic fibrosis was first identified in 1996. At that time, competing hypotheses about the pathogenesis of cystic fibrosis lung disease predicted very different responses to long-term inhalation of hypertonic saline.

RECENT FINDINGS

Recent benchtop research supports the hypothesis that the liquid layer lining the airways is depleted in cystic fibrosis. In addition to osmotically restoring this liquid layer, hypertonic saline improves the rheological properties of the mucus and stimulates cough. The net result is accelerated mucus clearance that is short-lived for single doses but sustained with regular inhalation. Long-term use improves lung function mildly but has marked benefits with respect to exacerbations, quality of life and absenteeism, without promoting infection or inflammation.

SUMMARY

Hypertonic saline appears broadly applicable as an inexpensive therapy for most patients with cystic fibrosis.

Inhaled bronchodilators for cystic fibrosis

BACKGROUND

Recurrent wheeze and breathlessness are common in people with cystic fibrosis, and bronchodilators are commonly prescribed. Despite their wide-scale and often long-term use, there is limited objective evidence about their efficacy in cystic fibrosis.

OBJECTIVES

To evaluate the effectiveness of inhaled bronchodilators in children and adults with cystic fibrosis.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic databases searches, and handsearches of relevant journals and abstract books of conference proceedings. Latest search of the Group's Trials Register: August 2005

SELECTION CRITERIA

Randomised or quasi-randomised trials comparing inhaled bronchodilators to placebo or another inhaled bronchodilator in people with CF, diagnosed clinically and by sweat or genetic testing and at all stages and severity of lung disease.

DATA COLLECTION AND ANALYSIS

The authors independently extracted data and assessed trial quality. If data were missing, the primary author was contacted where possible. The data were subgrouped into classes of bronchodilator and for each class into short-term effects (less than one week) and long-term effects (greater or equal to one week).

MAIN RESULTS

The search identified 43 references. Fourteen trials, with a total of 257 participants, were suitable for inclusion. The trials were all cross-over in design; in this case a meta-analysis was not possible. There were varied conclusions from the different trials, reflecting their heterogeneity. Compared to placebo, short-acting beta-2 agonists increased forced expiratory volume at one second (FEV(1)) in the short term in three out of five trials, and in the long-term increased peak expiratory flow rate in individuals who had been shown to have bronchial hyperreactivity or bronchodilator responsiveness or both. Compared to placebo, long-acting beta-2 agonists increased FEV(1) and forced expiratory flow between 25% and 75% of expiratory flow (FEF 25-75%) in the short term in participants known to have bronchodilator responsiveness, but produced inconsistent results in long-term trials. Short acting-anticholinergics had no consistent effect on lung function tests in either the short or the long term. We found no published trials of fenoterol, formoterol or tiotropium and the use of these agents in cystic fibrosis cannot be supported.

AUTHORS' CONCLUSIONS

It was not possible to determine fully the effectiveness of inhaled bronchodilators in cystic fibrosis as a meta-analysis was not possible. However, both short and long-acting beta-2 agonists can be beneficial both in the short and long term in individuals with demonstrable bronchodilator responsiveness or bronchial hyperrresponsiveness.

Effect of nebulized albuterol on blood glucose in patients with diabetes mellitus with and without cystic fibrosis

Over 90% of cystic fibrosis (CF) patients are treated with bronchodilators, and 6% have diabetes. Some with asthma also have diabetes, and most are treated with bronchodilators. Systemic administration of adrenergic agents can cause increases in blood glucose, but the effect of inhaled agents is unclear. A double-blind study was performed on 10 patients with type 1 diabetes mellitus (DM) without CF (3 male, 7 female, mean age 25.5 years) and 9 patients with insulin-dependent CF-related diabetes (CFRD) (8 male, 1 female, mean age 21.9 years). On 2 separate days before 9 AM fasting and the morning dose of insulin, 2.5 mg of albuterol or nebulized placebo were given. Blood glucose was measured by finger stick with a glucose reflectance meter before and 15, 30, 45, and 60 min after treatment. No significant changes from baseline or differences between placebo and albuterol occurred in either group. The mean maximum increase from baseline in DM was 20 mg/dl on placebo, and 38 mg/dl on albuterol; in the CFRD, the respective changes were 7 and 7 mg/dl. Two DM patients had a > 50 mg/dl increase on albuterol vs. placebo; no CFRD patients had differences of such magnitude. DM patients had greater increases from baseline than CFRD patients on placebo and albuterol. Differences reached statistical significance at 30 and 45 min on placebo, and 45 min on albuterol. Albuterol 2.5 mg by nebulizer causes no clinically significant increases in blood glucose in DM or CFRD patients. Diabetes patients without CF have a significantly greater increase of glucose with time (placebo or albuterol) than CFRD patients.

Interleukin-1beta differentially regulates beta2 adrenoreceptor and prostaglandin E2-mediated cAMP accumulation and chloride efflux from Calu-3 bronchial epithelial cells. Role of receptor changes, adenylyl cyclase, cyclo-oxygenase 2, and protein kinase A

Here we tested the effect of interleukin-1beta, a pro-inflammatory cytokine, on cAMP accumulation and chloride efflux in Calu-3 airway epithelial cells in response to ligands binding to adenylyl cyclase-coupled receptors such as the beta2 adrenoreceptor and EP prostanoid receptors. Interleukin-1beta significantly increased isoprenaline-induced cAMP accumulation by increasing beta2 adrenoreceptor numbers via a protein kinase A-dependent mechanism. In contrast, interleukin-1beta significantly impaired prostaglandin E2-induced cAMP accumulation by induction of cyclo-oxygenase-2, prostaglandin E2 production, and a resulting down-regulation of adenylyl cyclase. The cAMP changes were all mirrored by alterations in chloride efflux assessed using the fluorescent chloride probe N-(ethoxycarbonylmethyl)-6-methoxyquinolinium bromide with interleukin-1beta increasing chloride efflux in response to isoprenaline and reducing the response to prostaglandin E2. Studies with glibenclamide confirmed that chloride efflux was via the cystic fibrosis transmembrane conductance regulator. Calu-3 expresses EP4 receptors, but not EP2, and receptor expression is reduced by interleukin-1beta. Collectively, these results provide mechanistic insight into how interleukin-1beta can differentially regulate cAMP generation and chloride efflux in response to different adenylyl cyclase-coupled ligands in the same cell. These findings have important implications for diseases involving inflammation and abnormal ion flux such as cystic fibrosis.

Serial Lung Function and Responsiveness in Cystic Fibrosis during Early Childhood

In a 4-year prospective study, we evaluated specific airway resistance (sRaw) by whole-body plethysmography, respiratory resistance by the interrupter technique, and respiratory resistance and reactance at 5 Hz by the impulse oscillation technique combined with measurement of responsiveness to bronchodilators and cold air in 30 children (mean [range] age 5.7 [2 to 8] years) with cystic fibrosis (CF). Spirometry was done at school age. Mean sRaw was consistently abnormal: the mean z score (SD) was 2.52 (2.02) (p < 0.001) at the start and was unchanged 36 months later at 2.74 (2.02). Mean z score (SD) for FEV(1) at first satisfactory measurement, at a mean age (range) of 6.1 (4.9-7.5) years was -1.2 (1.2) and was further reduced to -1.85 (1.2) 4 years from inclusion at a mean age (range) of 9.9 (6.8-12) years. Neither respiratory resistance by the interrupter technique nor the impulse oscillation technique demonstrated consistent abnormal levels. Patients with CF as a group did not differ from healthy subjects in responsiveness to bronchodilators and cold air. sRaw may be a useful tool in CF during early childhood. Reduced lung function was documented from consistently abnormal levels of sRaw and FEV1 during the study. Bronchodilator responsiveness and response to cold air challenge were normal.

Pathophysiology and management of pulmonary infections in cystic fibrosis

This comprehensive State of the Art review summarizes the current published knowledge base regarding the pathophysiology and microbiology of pulmonary disease in cystic fibrosis (CF). The molecular basis of CF lung disease including the impact of defective cystic fibrosis transmembrane regulator (CFTR) protein function on airway physiology, mucociliary clearance, and establishment of Pseudomonas aeruginosa infection is described. An extensive review of the microbiology of CF lung disease with particular reference to infection with P. aeruginosa is provided. Other pathogens commonly associated with CF lung disease including Staphylococcal aureus, Burkholderia cepacia, Stenotrophomonas maltophilia, Achromobacter xylosoxidans and atypical mycobacteria are also described. Clinical presentation and assessment of CF lung disease including diagnostic microbiology and other measures of pulmonary health are reviewed. Current recommendations for management of CF lung disease are provided. An extensive review of antipseudomonal therapies in the settings of treatment for early P. aeruginosa infection, maintenance for patients with chronic P. aeruginosa infection, and treatment of exacerbation in pulmonary symptoms, as well as antibiotic therapies for other CF respiratory pathogens, are included. In addition, the article discusses infection control policies, therapies to optimize airway clearance and reduce inflammation, and potential future therapies.

Traitements inhales bronchodilatateurs et fluidifiants dans la mucoviscidose

Poor clearance of airway secretions contributes to the pulmonary disease in cystic fibrosis (CF). Bronchodilator therapy might benefit in CF, but the efficacy is controversial. Effects of mucolytic agents have not been demonstrated conclusively. Only, efficacy of recombinant human deoxyribonuclease (rhDNase) is established with a rapid onset of benefit.

Treatment of severe small airways disease in children with cystic fibrosis: alternatives to corticosteroids

A group of patients with cystic fibrosis (CF) have severe small airways disease characterized by wheeze, chest tightness and limited sputum production, often with deteriorating lung function. Suggested mechanisms include mucosal edema secondary to infection and inflammation, smooth muscle contraction caused by inflammatory mediators, and collapse of bronchiectatic airways. While treatment with long-term oral corticosteroids may result in symptomatic improvement, adverse effects often make them intolerable. Inhaled corticosteroids are used in many centers despite the lack of conclusive evidence of their efficacy. Therapeutic alternatives to corticosteroids are aimed at reversing bronchoconstriction and reducing inflammation. Many patients with CF are treated with short- and long-term inhaled bronchodilators, but data to support their use are inconclusive. Other attempted routes of administration for short-acting bronchodilators include the subcutaneous and intravenous routes, but clinical data are again lacking. Sodium cromoglycate (cromolyn sodium) has been studied, with little evidence of benefit. Theophyllines have also been studied, both intravenously and orally, with some effect, but are not often used in clinical practice. Nonsteroidal anti-inflammatory therapies include ibuprofen, macrolide antibiotics, intravenous immunoglobulin, cyclosporine, and leukotriene antagonists. Ibuprofen has been shown to be useful in patients with mild CF disease, but concerns about potential adverse effects have limited its use. The results of various macrolide studies are awaited, but to date there are no long-term studies published. While there is great interest in the potential of intravenous immunoglobulin, cyclosporine and leukotriene antagonists, the evidence for their effectiveness comes from anecdotal reports, thus there is currently insufficient data to support their use. Since this is a small group of patients, it is unlikely that sufficient numbers will ever be recruited for these studies; thus it is probable that drugs will be tried on an individual patient basis. The order in which they are attempted is unclear, but it would be sensible to try the least invasive medication with the least adverse effects first, moving on to more potent, but more toxic drugs if that treatment fails.

Effectiveness and tolerability of high-dose salmeterol in cystic fibrosis

The efficacy and tolerability of high-dose salmeterol (100 mcg, BID) and albuterol (2.5 mg, BID) were compared with those of albuterol (2.5 mg, BID) in outpatients with cystic fibrosis in a randomized, double-blind, double-dummy, placebo-controlled, crossover study with both short- (4 weeks of each) and long-term (24 weeks of each) treatment periods. The primary outcome measure was the difference in mean change in forced expired volume in 1 sec (FEV(1)) from baseline to the end of each treatment, and secondary measures included changes in forced vital capacity (FVC), forced expiratory flow between 25-75% of FVC (FEF(25-75)), patient-rated weekly symptom scores, number of extra (rescue) albuterol treatments, and number of antibiotic treatments. Tolerability was evaluated by changes in vital signs and adverse events.Thirty-six out of 44 patients enrolled finished the short-term treatment period, and 19 out of 23 who continued the study also finished the long-term treatment period. There was no significant difference in the mean % change in FEV(1) from baseline to completion of 4 weeks with each drug in the short-term treatment period (0.1% vs. 0.06%, albuterol vs. salmeterol; respectively). In the long-term treatment period, there was a significant decrease from baseline in FEV(1) with albuterol vs. salmeterol, as measured after both 12 and 24 weeks of each treatment (-6.2% vs. 1.8%, P = 0.013 after 12 weeks, and -6.5% vs. 1.7%, P = 0.002, after 24 weeks, respectively). In both treatment periods, salmeterol was well-tolerated. While there were more rescue treatments per patient per week with albuterol than with salmeterol treatment in both the short- and long-term periods (0.67 vs. 0.40 and 1.76 vs. 0.74, respectively), rescue treatments were needed significantly more often for only the long-term period with albuterol compared to salmeterol (P = 0.022). Also, there were more antibiotic interventions with albuterol than with salmeterol treatment in both the short- and long-term periods (25 vs. 10 and 56 vs. 42, respectively); however, antibiotics were needed significantly more often for only the short-term period (P = 0.011). In addition, there was a significantly higher symptom score with albuterol vs. salmeterol treatment during the second half of the long-term period (1.24 vs. 0.89, P = 0.001).In conclusion, long-term high-dose salmeterol was equally safe and was associated with better pulmonary function, fewer interventions, and fewer respiratory symptoms compared to standard therapy with albuterol in a population of outpatients with mild to moderate CF.

Airways reactivity in patients with CF

Airways reactivity, hyper-reactivity, and hyper-responsiveness are terms used to describe airways for which there appears to be increased bronchial smooth muscle tone or responsiveness. Some patients with cystic fibrosis (CF) have concomitant asthma causing airway hyperresponsiveness as manifested by recurrent acute symptoms of dyspnea that is impressively responsive to an inhaled beta 2 agonist and/or systemic corticosteroids. However, many others have a degree of bronchodilator responsiveness in the absence of an impressive clinical response to such anti-asthmatic treatment. In contrast to those with asthma, exercise does not induce bronchospasm and can even cause bronchodilatation in patients with CF who have bronchodilator responsiveness in the absence of asthma. The airway hyperresponsiveness of CF also differs in its response to histamine induced bronchospasm which is effectively reversed with ipratropium in patients with CF who symptomatically do not have asthma, whereas ipratropium does not adequately reverse histamine-induced bronchospasm in those with concomitant symptoms of asthma. These and other data suggest that the increased airway reactivity in patients with CF is vagally mediated and results from the airway damage caused by the lung disease. The use of bronchodilators as a routine part of CF lung disease care is controversial, but there is little evidence that treating airway reactivity in patients with CF is of clinical importance as a routine measure in the absence of clinical asthma. Definite subjective improvement in symptoms or improved sputum production when a bronchodilator precedes chest physical therapy should be sought to justify continued use in individual patients.

Effects of salmeterol on arterial oxyhemoglobin saturations in patients with cystic fibrosis

Sleep-related oxygen desaturation has been described in patients with cystic fibrosis (CF). Thus we studied the effects of inhaled Salmeterol xinafoate, a long-acting beta-2 agonist, on transcutaneous oxyhemoglobin saturation in sleeping, stable CF patients. Patients with stable CF (n = 23) were divided into responders and nonresponders to beta-2 agonists, based on an albuterol challenge during daytime testing, and then they received salmeterol before sleep, in a double-blind crossover design. Overnight oxyhemoglobin saturation measurements and spirometry on awakening were performed. Salmeterol administration before sleep resulted in statistically significant increases in mean arterial oxyhemoglobin saturation and in FEV(1) and FEF(25-75) on awakening compared to placebo values, but only in patients responding to daytime albuterol inhalation by showing improvement in lung function. We conclude that salmeterol inhalation at bedtime could prevent or reduce nocturnal hypoxemia in daytime albuterol-responsive CF patients, thus improving the long-term clinical outcome of CF lung disease.

The effect of regular salbutamol on lung function and bronchial responsiveness in patients with primary ciliary dyskinesia

STUDY OBJECTIVE

There is growing evidence that regular beta(2)-agonist use in patients with asthma is associated with decreased airway caliber and increased bronchial responsiveness. The aim of this study was to determine whether regular treatment with beta(2)-agonists induces changes in lung function and bronchial responsiveness in patients with primary ciliary dyskinesia.

DESIGN

A randomized, double-blind, placebo-controlled, crossover study.

PATIENTS

Nineteen children with primary ciliary dyskinesia.

INTERVENTIONS

Subjects received inhaled salbutamol or identical placebo (2 x 100 microg qid) for periods of 6 weeks with a wash-out period of 4 weeks.

MEASUREMENTS AND RESULTS

FEV(1) was measured before and 3 weeks and 6 weeks after salbutamol or placebo treatment. High-dose methacholine inhalation tests were performed before and 6 weeks after each treatment. The provocative concentration of methacholine producing a 20% fall in FEV(1) (PC(20)) and maximal airway narrowing (MDeltaFFEV(1)) was measured. No significant change in FEV(1) was observed during the salbutamol or placebo periods. No significant differences in the parameters of bronchial responsiveness (PC(20) and MDeltaFFEV(1)) were noted as the result of either salbutamol or placebo treatment.

CONCLUSION

Our data have shown that salbutamol, inhaled regularly for 6 weeks, did not cause either a decline in lung function or an increase in bronchial responsiveness in subjects with primary ciliary dyskinesia.

Effects of standard and high doses of salmeterol on lung function of hospitalized patients with cystic fibrosis

In a recent investigation we found that hospitalized patients with cystic fibrosis who received 0.5 cc of 0.5% albuterol nebulizer solution TID significantly increased their pulmonary function across the day, but fell back to baseline overnight. To determine whether this fall could be prevented by the long-acting beta-2 agonist salmeterol at both standard (2 puffs: 42 mcg BID) and high (4 puffs, 84 mcg BID) doses, we evaluated the effects of salmeterol vs. albuterol (2 puffs, 180 mcg QID, and 4 puffs, 360 mcg BID) in a placebo-controlled three-way random crossover, double-blind trial. Eighteen patients in the low-dose group and 10 of the same 18 patients in the high-dose group completed the 3 consecutive days of testing and received either salmeterol, albuterol, or placebo with each of four chest physiotherapy sessions given at 7 AM, 11 AM, 3 PM, and 7 PM. At standard doses (2 puffs), the mean percent changes in FEV1 pre- to post-7 AM therapy for salmeterol (5.5%) and albuterol (9.9%) were significantly greater than with placebo (-1.2%) (P < 0.05 and 0.01, respectively). The mean percent changes in FEV1 from morning baseline with salmeterol were also significantly greater than placebo before 3 PM (12.1% vs. 5.4%, P < 0.01), and neither albuterol nor salmeterol were significantly greater than placebo after 3 PM. At standard doses there was a significant carryover effect with salmeterol to the next morning for the FEV1 (7.3%) when compared to placebo (1.5%) and albuterol (-0.7%) (P < 0.05 and 0.05, respectively). At high doses (4 puffs), the mean percent change in FEV1 with pre- to post-7 AM therapy increased to 22.7% and remained significantly greater than with placebo until pretherapy at 7 PM. The carryover effect the next morning was 14.7%. Salmeterol at 4 puffs compared favorably to albuterol nebulizer therapy given TID in both the incidence of responders for the FEV1 (70% vs. 71%) and the mean changes after therapy at 7 AM (22.7% vs. 14.9%), and provided greater carryover effects to the next morning (14.7% vs. -0.7%), thus preventing the fall in pulmonary function back to baseline overnight. We recommend the use of high-dose salmeterol in hospitalized patients with FVC values of 40% of predicted or greater, starting with 2 and increasing to 4 puffs BID as tolerated.

Basic therapies in cystic fibrosis. Does standard therapy work?

Epidemiologic data demonstrate a dramatic improvement in survival for cystic fibrosis (CF) over the last few decades and projections suggest that trend will continue. Standard therapy works and should be aggressively applied to this patient population. Although the specific therapies have evolved over the years, the basic tenets of CF care remain unchanged and include antibiotics to control infection, airway clearance, and adequate nutrition. This article focuses on treatment of the pulmonary disease and includes a discussion of the following specific components of a standard therapeutic approach to CF: (1) antibiotics, (2) airway clearance and exercise, (3) mucolytics, (4) bronchodilators, (5) oxygen, (6) anti-inflammatory therapies, and (7) nutritional support. Judicious application of these therapies coupled with careful monitoring of pulmonary, nutritional, and metabolic parameters results in most CF patients surviving into adulthood with an acceptable quality of life.

[International registry on mucoviscidosis: comparison of the French data with the European data for 1995]

BACKGROUND

The Epidemiologic Registry of Cystic Fibrosis (ERCF) is an international registry, sponsored by Roche Laboratories, collecting data about CF patients in Europe. The aim of the our study is to compare the French data with the European data collected during the year 1995.

RESULTS

By December 31st 1995, 8,831 patients have been enrolled in Europe, including 1,457 patients in France. French CF patients are younger (mean age = 12.6 years) than European CF patients (mean age = 14.6 years). Genotype is better characterised in France (89 vs 75% for European patients), but only 49% of CF patients are homozygote for the DF508 deletion in France versus 77% in Denmark. Two clinical features of French CF patients are interesting: 1) presence of Staphylococcus aureus and Haemophilus influenzae (52%) is more frequent in France than in Europe (65 vs 48% and 52 vs 29%, respectively), 2) lung function tests (forced vital capacity [FVC]), forced expiratory volume per second [FEV1] are worse in France (P < 0.001) particularly in the older patients (> 18 years): 39% of these patients in France have a FEV1 < 40% of predicted value compared to only 29% in Europe. Similarly there are fewer patients in this age group in France (22 vs 31% in Europe) having a FVC > 90% of the predicted value in France. With regard to the treatment, three differences emerge: 1) dornase alfa is more used in France (55 vs only 34% in Europe); 2) use of prophylactic inhaled and oral antibiotics is less common in France than in all age groups; 3) the use of inhaled corticosteroids and bronchodilators is also less common in France despite the same incidence of asthma-like symptoms. Finally we notice that the mean age at death in 1995 is 18.2 years (+/- 2.38) in France and 20.6 years (+/- 0.85) in Europe.

CONCLUSION

These results are preliminary because 1995 is the first year for ERCF in France and a low percentage of French CF patients are included for this year. Therefore they must be interpreted with caution. Nevertheless, we can hypothesise about a relationship between these results and a less aggressive treatment regimen. The impact of dornase alfa use on prognosis seems interesting to analyse in future years.

A placebo-controlled, double-blind trial of the long-term effects of albuterol administration in patients with cystic fibrosis

This placebo-controlled study was designed to confirm a previously performed open label study that showed significant improvement in spirometry on maintenance therapy with albuterol for 1 year. In a double-blind, cross-over trial, albuterol (by metered dose inhaler) 180 microg b.i.d. or placebo were given for 6 months each. Spirometry was monitored at the start, and 3 and 6 months following initiation of each arm of the study. Peak expiratory flow rate (PEFR) was measured twice daily at home before and after study drug administration. Only patients with clinically detectable lung disease were enrolled. Twenty-one patients finished the study. All spirometric tests showed a significant improvement from start to end of the 6 month treatment with albuterol; there was no significant change on placebo. Forced vital capacity improved by 8.2% and forced expiratory volume in 1 s by 12.1% on albuterol therapy. Nevertheless, there was no significant difference between change on albuterol and change on placebo. Home measurements of PEFR showed a significant improvement of 4.7% on albuterol and a non-significant change of 2.0% on placebo from the first to the last week of treatment. None of the long-term improvements (spirometry or home PEFR) correlated with mean daily bronchodilation. For albuterol, the number of days of hospitalization was less than half that for patients on placebo (1.0/patient on albuterol versus 2.6 on placebo), but this did not reach statistical significance. These results suggest a beneficial effect from maintenance therapy with albuterol. Bronchodilation alone probably cannot explain the long-term benefits of albuterol, and other mechanisms may play a role. The lack of significant difference between change on albuterol and change on placebo is probably due to too small a number of patients in this study and lack of statistical power.

Genetic and immunologic aspects of cystic fibrosis

LEARNING OBJECTIVES

Reading this article will enable the readers to reinforce their knowledge of the pathophysiology of cystic fibrosis (CF), the pathogenesis of the lung disease, the criteria for diagnosis, and CF genotype/phenotype relationships. The focus of this review is on the genetic and immunologic aspects of CF.

DATA SOURCE

Relevant articles, current texts, data presented at the annual North American Cystic Fibrosis Conferences and distributed to the Directors of CF Centers by the CF Foundation were reviewed. A MEDLINE database using subject keywords was searched from 1987 to date. Background information derived from the author's 33 years of clinical experience at three of the CF Foundation's CF Care, Teaching and Resource Centers was also included.

STUDY SELECTION

Since CF is an inherited disorder, the genetic aspects are emphasized. With the cloning of the CF gene, DNA analysis has assumed an important role in confirming the clinical diagnosis and in the improved understanding of the pathophysiology of this disorder. Although DNA testing is highly specific, it is not very sensitive.

RESULTS

Cystic fibrosis gene structure and function are described briefly. The pathophysiology of CF, as it relates to the CF gene defect, and the current knowledge of the pathogenesis of the lung disease are reviewed. The criteria for the diagnosis proposed by the Clinical Practice Guidelines for CF are discussed. Problems of establishing the diagnosis and the importance of correlations of laboratory and clinical findings in CF are emphasized.

CONCLUSIONS

As a multisystem disorder, CF can masquerade as other disorders, including allergic respiratory disease. Primary care physicians often refer patients to allergists/immunologists because of recurrent respiratory problems. This review discusses the genetic heterogeneity of CF.