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* From the Department of Medicine (Dr. Alvarez-Mon), CSIC R&D Associated Unit, Hospital Príncipe de Asturias, Alcalá University, Alcalá de Henares, Madrid; Respiratory Department (Dr. Miravitlles), Hospital Clinic (IDIBAPS), Barcelona; Respiratory Department (Dr. Morera), Hospital German Trias i Pujol, Badalona; Respiratory Department (Dr. Callol), Hospital Central de la Defensa, Complutense University, Madrid; and Respiratory Department (Dr. Alvarez-Sala), Hospital Clínico San Carlos, Complutense University, Madrid, Spain.
See Appendix for a complete list of study participants.
Correspondence to: Melchor Alvarez-Mon, MD, PhD, Departmento de Medicina, Universidad de Alcalá, Carretera Madrid-Barcelona, Km 33,600, E-28871 Alcalá de Henares (Madrid), Spain; e-mail: mams{at}tsai.es
| Abstract |
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Objectives: We analyzed the effect of AM3 on exacerbation frequency and health-related quality of life (HRQL) of COPD patients with moderate disease.
Design: A randomized, double-blind, placebo-controlled trial.
Setting: Outpatient departments of 21 hospitals.
Methods: A total of 253 COPD patients with a mean age of 67.7 years (SD, 8.1 years) and mean FEV1 percentage of predicted of 49.6% (SD, 10.2%) were evaluated. Patients received (orally) either 3 g/d AM3 or a matched placebo for 180 consecutive days. Patient quality of life was measured using the St. Georges Respiratory Questionnaire (SGRQ).
Results: There were no differences in the exacerbation frequency of the two groups (0.82 episodes per patient in the AM3 arm vs 0.84 in the placebo arm), and 55.3% of patients were exacerbation free in the AM3 arm compared to 48.8% in the placebo arm (p = 0.11). At the end of treatment, quality of life was significantly better in the AM3 arm than in the placebo arm (SGRQ total score, 32.9; SD, 16.4, compared to 37.5; SD, 17.5 [p < 0.05]: activity score, 47.5; SD, 22.4, compared to 54.6; SD, 20.5 [p < 0.05]). The improvements in total SGRQ scores were 8.9 U (SD, 13.4 U) in the AM3 arm and 5.6 U (SD, 15.9 U) in the placebo arm (p = 0.076). Improvements on the symptoms subscale were 15.9 U (SD, 20.7 U) for the AM3 arm and 10.2 U (SD, 21.3 U) for the placebo arm (p < 0.05). Both AM3 and the placebo were clinically, biochemically, and hematologically well tolerated.
Conclusions: AM3 is a safe, easily tolerated, effective treatment that improves the quality of life of COPD patients as measured by SGRQ scores. This effect was observed with no significant reduction in the frequency of exacerbations.
Key Words: AM3 clinical trial COPD health-related quality of life St. Georges Respiratory Questionnaire
| Introduction |
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Exacerbations are a frequent event in the natural history of the disease. Patients with frequent exacerbations experience an accelerated decline in lung function3 and health-related quality of life (HRQL).45 Treatments that reduce the frequency of exacerbations may eventually reduce the rate of decline of HRQL.6 This has been observed with inhaled corticosteroids, although some of the improvements seen are probably explained by the pharmacologic effect of the drug rather than a reduction in the number of exacerbations.7
In addition to its impact on patient life span and health-care costs, there is growing concern over the impact of COPD on HRQL. HRQL has been used as an independent predictor of hospitalization and mortality,8 and there is evidence that it is already reduced in the initial phases of the disease.9 The importance of improving HRQL is addressed in consensus documents on COPD therapy.10 HRQL in COPD patients appears to depend on multiple factors, including the so-called "systemic effects" of the disease, such as systemic inflammation, skeletal muscle dysfunction, and nutritional problems leading to weight loss.11
Chronic inflammation of the airways plays an essential pathogenic role in COPD. Its relationship with the degree of airflow obstruction and with susceptibility to periods of exacerbation is well established.3 In addition to local inflammation in the lungs, there is growing evidence that systemic inflammatory events occur, which may be involved in HRQL impairment.1213
The effects of standard respiratory medication (ie, different combinations of oral and inhaled bronchodilators and antiinflammatory drugs) on HRQL in patients with stable COPD are controversial. Although positive results on HRQL have been obtained with long-acting ß2-adrenergic agonists,14 long-acting anticholinergic drugs,15 and inhaled corticosteroids,16 there is evidence that the use of multiple drugs is associated with poorer quality of life in COPD patients.17
AM3 is a commercially available immunomodulator with a low toxicity profile. Its active ingredient is a polysaccharide/protein compound purified from Candida utilis. AM3 has been shown to recover and normalize the phagocytic deficits of polymorphonuclear cells and macrophages, and to correct the lytic activity of natural killer cells in patients with stable COPD.18 Clinical studies1920 have shown the efficacy of AM3 as a vaccine adjuvant in both healthy and immunocompromised subjects. This article reports a randomized, double-blind, placebo-controlled, clinical trial to assess the effects of AM3 treatment on exacerbation frequency and HRQL in stable COPD patients receiving standard respiratory medication.
| Materials and Methods |
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The trial was approved by the clinical research ethics committees of all the participating centers. All patients gave their written, informed consent to be included.
Patients
COPD patients, both smokers and ex-smokers (at least 20 pack-years), were recruited at the outpatient departments of 21 hospitals during the year 2000. All recruited patients had chronic, irreversible airflow limitation defined as an FEV1 of 35 to 70% of the predicted value, and an FEV1/FVC ratio < 70%. Patients with salbutamol (200 µg) response showing an FEV1 > 15% and > 200 mL were excluded. At least two episodes of acute respiratory exacerbation during the previous year were required for inclusion. All patients were clinically stable and had no history of infection or exacerbation of their illness in the 4 weeks prior to the trial.
Patients with bronchiectasias, active pulmonary tuberculosis, lung cancer, cancer of any other organ, cystic fibrosis, restrictive lung disease, heart failure (New York Heart Association functional class
III), advanced kidney failure (serum creatinine > 4 mg/dL), or uncompensated liver disease (Child-Pugh stage B or C) were excluded. Patients receiving treatment with immunosuppressors, immunomodulators, cimetidine, or any other drug that might modify the immune response were also excluded, as were those treated with systemic corticoids in the 2 weeks prior to the study.
Throughout the study, all patients received conventional respiratory medication (bronchodilators, antiinflammatory agents, oxygen therapy, etc.) for their underlying condition as their physicians saw fit. Inhaled steroids were administered equivalent to
800 µg/d of budesonide. Systemic corticosteroids were administered in cases of exacerbation for no longer than 2 weeks at a time.
At the time of inclusion, the nutritional status of all patients was determined by calculating body mass index (BMI). All patients underwent forced spirometry before and after bronchodilation with salbutamol, arterial blood gas analysis, chest radiography, and an ECG, and all completed the SGRQ. At the end of the study, the BMIs were calculated again, the spirometry test was retaken, and the SGRQ completed once more. Patients attended scheduled monthly visits during which investigators recorded the incidence of exacerbations and the possible appearance of adverse effects of AM3 treatment. Patients were also instructed to contact the researchers by telephone if they had exacerbation symptoms.
Determination of HRQL
HRQL was measured using the validated Spanish version of the SGRQ.21 This questionnaire, specific for respiratory disease, contains 76 questions that collect information on three components: the frequency and severity of respiratory symptoms (symptoms), activities caused by or limited by dyspnea (activity), and changes in social and psychosocial functions caused by the disease (impact). The scores for each component and the total score are based on a 0 to 100 scale (from no effect to maximum deterioration). Therefore, any reduction in SGRQ score reflects an improvement in HRQL. The variation in score required for a minimum clinical difference to be accepted has been established as four points.22
Statistical Analysis
Intragroup comparisons of the number of exacerbations and SGRQ scores (symptoms, activity, impact, and total score) were performed using the Wilcoxon paired-sample test. The nonparametric Mann-Whitney U test was used for intergroup comparisons. Proportions were compared using
2 test. Significance was set at p < 0.05.
| Results |
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50 to < 80%; n = 63 in the AM3 arm and n = 50 in the placebo group) or stage III (FEV1 percentage of predicted
30 to < 50%; n = 69 in the AM3 arm and n = 71 in the placebo group). Nearly all patients (92.3%) received at least one respiratory medication for COPD: 83.4% received ß2-adrenergic agonists, 66.0% received inhaled steroids, and 62.8% received anticholinergic agents; 38.3% of medicated patients received all three treatments. Theophyllines were also prescribed for 26.5%. No significant differences were seen in the medication prescribed to patients in the two arms of the trial; patient medication did not change significantly during the study period.
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| Discussion |
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The pharmacologic treatment of COPD has reached a point where different pathogenic mechanisms can be somewhat ameliorated. The control of airway inflammation, of the functional phenomena associated with the hypersecretion of mucus, and of the increased contractility of bronchial smooth muscle now achieves clinical benefits.23 It is well established that long-acting ß2-adrenergic agonists and long-acting anticholinergic agents improve the HRQL in COPD patients, as determined by the SGRQ.1213 It has also been found that inhaled steroids can delay the progression of HRQL impairment in COPD patients.24 However, it is clear that the medical treatment of this disease needs to be optimized.25 Attempts to definitively modify the natural history of the disease, other than smoking cessation, have not been as successful as expected. The improvement of HRQL in COPD patients is therefore still a therapeutic goal. Interestingly, the beneficial effect of AM3 was particularly remarkable in patients receiving inhaled steroids as part of their usual respiratory medication. It has been demonstrated that inhaled steroids have poor antiinflammatory effects on stable COPD.26 This corticosteroid resistance has been related to increased oxidative stress and peroxynitrite formation, which reduces the antiinflammatory action of corticosteroids.27 It has been shown28 that AM3 inhibits inducible nitric oxide synthetase in response to inflammatory signals. This might play a role in the marked improvement of HRQL in COPD patients treated with inhaled steroids. In the present trial, we also found an improvement in SGRQ scores in the placebo group: this has been observed by other authors and might be due to the frequent and close follow-up of the patients during the study.5
Treatment with AM3 failed to lead to a reduction in the number of exacerbations. Studies45 have demonstrated that longer periods of observation are required for any effect on the number of exacerbations to be seen. Only a nonsignificant trend toward a higher number of patients free of exacerbations during the 6-month follow-up was observed. This lack of statistical significance in the reduction of exacerbations in the AM3-treated group might be due to the number of patients studied being smaller than expected (only 253 of 360 patients entered completed study). We cannot exclude, however, that this nonsignificant reduction in exacerbations observed in the AM3 group might be involved in the demonstrated improvement in HRQL. If confirmed in larger studies, this could mean that AM3 may prevent exacerbations in patients with mild disease, who usually have infrequent exacerbations. To evaluate the possible effect of AM3 in preventing exacerbations in patients with severe disease would require larger populations and extended follow-up times.
According to the present results, the effect of AM3 on HRQL cannot be explained by a reduction in exacerbations. In contrast, Spencer et al7 report that the beneficial effect of inhaled corticosteroids on HRQL of COPD patients is largely due to their effect on exacerbation frequency. However, there was a small effect of the treatment on HRQL that was independent of its effect on exacerbations. This could be due to the pharmacologic effect of the drug per se. Similarly, the impact on HRQL induced by AM3 treatment may be related to its immunomodulatory and antiinflammatory effect, independent of any impact on exacerbation frequency.
Several pathogenic mechanisms appear to be involved in the impairment of HRQL in COPD patients. COPD-related lung inflammation has been associated with immune system disturbances, which may play an important role in the predisposition of patients to infectious and noninfectious exacerbations.29 These immune alterations are also thought to be involved in the maintenance and progression of bronchial inflammatory lesions and in the impairment in lung function.3031 It is recognized that COPD is also associated with a systemic inflammatory response, identified by the increased serum levels of proinflammatory cytokines and disturbances in peripheral blood immune cell subsets. This systemic inflammatory stage might be also involved in the impairment of HRLQ in these patients. The beneficial effects of AM3 on HRQL might be due to its wide range of effects on the immune system. We have recently reported that in COPD patients, AM3 activates and normalizes the effector functions of the neutrophils, monocytes, and natural killer cells involved in defense against bacteria and viruses.18 AM3 is also able to inhibit the production of proinflammatory cytokines, particularly tumor necrosis factor-
.32 These antiinflammatory effects of AM3 might be involved in the observed improvement of HRQL, and might explain the impressive impact of AM3 treatment on the SGRQ symptoms score. Among the noninfectious mechanisms triggering inflammation in COPD patients, the strenuous demand and functional disturbance of the respiratory muscles has been implicated in the generation of systemic inflammation, negatively affecting HRLQ.33 In this regard, AM3 has been shown to protect against muscle damage induced by strenuous demand in players of competitive sport.34 This protective effect might also occur in COPD patients and be involved in the improvement of HRQL.
The pharmacologic treatment of COPD remains a therapeutic goal. The present work shows that AM3 is able to improve HRQL in COPD patients (as determined by SGRQ), and to improve the results obtained with respiratory medication, particularly inhaled corticosteroids.
| Appendix |
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| Acknowledgements |
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| Footnotes |
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All data acquisition and analysis was completed under the direction of Melchor Alvarez-Mon, MD PhD at the Department of Medicine, Alcalá University.
This study was funded by I.F. Cantabria.
Received for publication July 9, 2004. Accepted for publication October 26, 2004.
| References |
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production by an HPA axis-dependent mechanism. Int Immunopharmacol 2002;2,807-813[CrossRef][ISI][Medline]
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