点击显示 收起
Departments of Pulmonology and Allergology, University Medical Center Groningen, Groningen, the Netherlands
ABSTRACT
Rationale: Tumor necrosis factor- is believed to be important in the induction and maintenance of airway inflammation in chronic obstructive pulmonary disease. Objectives: We aimed to evaluate the effect of the antieCtumor necrosis factor- drug infliximab in patients with chronic obstructive pulmonary disease, with percentage of sputum neutrophils as the primary endpoint. Methods: We performed an exploratory single-center, double-blind, placebo-controlled, randomized, phase 2 trial in which 22 current smokers with mild-to-moderate chronic obstructive pulmonary disease participated. Fourteen patients received three infusions of infliximab (5 mg/kg) at Weeks 0, 2, and 6, and eight patients received placebo infusions. Sputum samples, respiratory symptoms, quality of life, exhaled nitric oxide, lung function parameters, bronchial hyperresponsiveness, resting energy expenditure, and side effects were evaluated. Measurements and Main Results: This study did not show a positive short-term effect of infliximab on airway inflammation, lung function, resting energy expenditure, or quality of life. Exhaled nitric oxide increased significantly at Day 2, Week 6, and Week 8 in patients receiving infliximab compared with those receiving placebo. Eight patients in the infliximab group (vs. none in the placebo group) reported increased coughing, but no serious adverse events or increase in respiratory infections were reported during 9 weeks of follow-up. Conclusions: In this short-term study, no clinically beneficial effects of infliximab were observed, and there were no significant safety issues. Definite conclusions concerning the effectiveness of infliximab treatment in chronic obstructive pulmonary disease await additional studies, including those with a larger number of patients with more advanced disease.
Key Words: chronic obstructive pulmonary disease; inflammation; tumor necrosis factor-
Chronic obstructive pulmonary disease (COPD) is an inflammatory lung disease resulting in progressive lung function loss. It is one of the leading causes of morbidity and mortality worldwide, and its prevalence is still rising (2). Smoking cessation at an early stage of the disease is the most important intervention to slow down lung functional loss, but success rates are low (3), and airway inflammation appears to persist (4). Unfortunately, no antiinflammatory agents are currently available that effectively reduce the underlying airway inflammation and/or stop this progressive decline in lung function (5).
Airway inflammation in COPD is characterized by the presence of mononuclear cells, neutrophils, and their mediators. The cytokine tumor necrosis factor- (TNF-) is believed to play a central role in the pathophysiology of COPD (6). TNF- enhances neutrophil chemotaxis and migration by inducing the expression of chemokine interleukin 8 (IL-8) and upregulating endothelial adhesion molecules (7, 8). In vivo, elevated levels of TNF- have been demonstrated in peripheral blood and sputum of patients with stable COPD (9, 10), and a polymorphism of the promoter region of the TNF- gene has been implicated in the occurrence, severity, and mortality risk of COPD (11eC13).
Nutritional depletion is present in 20% of patients with COPD (14) and is associated with an increase in daily energy expenditure and in levels of inflammatory mediators (15). TNF- seems to be especially important among these inflammatory mediators because it correlates with increased energy expenditure. Furthermore, increased serum TNF- levels are found in a subgroup of patients with nutritional depletion (9, 16, 17).
Infliximab is a chimeric monoclonal antibody that binds with high affinity and specificity to human soluble and membrane-bound TNF- and neutralizes its biologic activity (18, 19). Infliximab has been shown to improve clinical and inflammatory parameters in patients with Crohn's disease and rheumatoid arthritis (20eC23). We designed a randomized, double-blind, placebo-controlled, proof-of-principle phase 2 study to evaluate whether short-term treatment with infliximab inhibits airway inflammation in patients with stable COPD, with percentage of sputum neutrophils being the primary endpoint. Secondary objectives of the study included evaluation of the effect of infliximab on respiratory symptoms, quality-of-life indicators, and lung function parameters. Another secondary objective was the evaluation of safety and tolerability of short-term infliximab therapy in COPD. Tertiary objectives included evaluation of infliximab treatment's effects on resting energy expenditure (REE) levels, and on exhaled nitric oxide (eNO) values. Some of the results of these studies have been previously reported in the form of an abstract (1).
METHODS
Design of the Study
We performed a single-center, randomized, double-blind, placebo-controlled pilot study. Patients with COPD were randomized to treatment with infliximab (Remicade; Centocor, Malvern, PA) at 5 mg/kg (14 patients) or with placebo (8 patients), with each treatment to be administered by infusion at Weeks 0, 2, and 6. A minimization method was used to provide groups balanced for age ( 60 or > 60 years), FEV1 ( 60 or > 60%), and number of exacerbations per year ( 2 or > 2). Sputum samples, spirometry, diffusion capacity, eNO, and REE were evaluated at Day 1 (baseline) and Day 2, and at Weeks 2, 6, and 8. The Clinical COPD Questionnaire (CCQ) (24) was evaluated at Day 1, and at Weeks 2, 6, and 8. The St. George Respiratory Questionnaire (SGRQ; assessing quality of life) and the concentration of adenosine 5'-monophosphate causing FEV1 to drop by 20% (PC20 AMP) were measured at baseline and subsequently at Weeks 8 and 9, respectively. Safety evaluations are described in the online supplement.
Subjects
Twenty-two patients with symptomatic COPD were enrolled, all with a postbronchodilator value FEV1/FVC ratio below 70% and FEV1 greater than 1.5 L. All patients were current smokers (> 5 cigarettes/day, > 10 pack-years). Exclusion criteria are presented in the online supplement. The medical ethics committee of our institute approved the study. Written, informed consent was obtained from all patients.
Pulmonary Function Tests, REE, and eNO
FEV1 and FVC were measured according to the guidelines of the European Respiratory Society (25). Diffusion capacity for carbon monoxide (expressed by transfer factor for carbon monoxide and TLCO divided by the alveolar volume was measured using the single breatheCholding method, according to international guidelines (25). Airway hyperresponsiveness to adenosine 5'-monophosphate was determined using standardized methods (26). REE was measured by an open-circuit, indirect calometry system using a ventilated hood system (Oxyconbeta; Jaeger, Wurzburg, Germany), as described previously (27). eNO levels were determined by a chemiluminescence analyzer (CLD 700 AL; Ecophysics, Durnten, Switzerland) using the American Thoracic Society guidelines (28).
Sputum Induction and Processing
Sputum was induced according to a modified standard technique (29) using 4.5% hypertonic saline. Sputum was processed within 120 minutes by a modified method of Rutgers and colleagues (29).
IL-6 and IL-8 were measured in sputum supernatant by commercial ELISA (Sanquin, Amsterdam, the Netherlands). Neutrophil elastase activity was measured by chromogenic substrate assay (N-methoxysuccinyl-ala-ala-pro-val-p-nitroanilide; Sigma, Poole, UK) (30).
Statistical Analyses
Clinical characteristics are presented as means (± SD) unless stated otherwise. All effect parameters are presented as medians with ranges. Differences in changes from baseline between the two treatment arms were tested with a Mann-Whitney test. A p value of less than 0.05 was considered statistically significant.
RESULTS
No significant differences in baseline characteristics were observed between the infliximab and placebo treatment groups (Tables 1 and 2). Infliximab treatment was not associated with significant changes in the absolute number or percentage of inflammatory cells in sputum compared with that in placebo (Table 3). In particular, infliximab treatment did not affect the primary endpoint of the study, the percentage of sputum neutrophils. In addition, changes in IL-8 and IL-6 levels did not differ between infliximab and placebo treatment groups (Table 3). Neutrophil elastase could not be detected in all sputum samples.
Changes in FEV1, FEV1/FVC (data not shown), and KCO/VA did not differ between the infliximab and placebo treatment groups (Table 2). The median change in eNO, however, was significantly higher at Day 2, Week 6, and Week 8 with infliximab treatment compared with placebo. Changes in REE and bronchial hyperresponsiveness to adenosine 5'-monophosphate did not differ between the infliximab and placebo treatment groups (Table 2), nor did respiratory symptoms and quality-of-life indicators (data not shown).
No serious adverse events were reported for either treatment group during the 9-week follow-up period. All three infusions were generally well tolerated; one subject who received infliximab withdrew from the study after the first infusion due to flulike symptoms without other evidence of serious disease or any abnormalities shown by physical examination or laboratory values. The most frequently reported adverse events are shown in Table 4. Eight patients in the infliximab group reported increased cough, an incidence that was significantly greater than in the placebo group. Patients did not report more respiratory tract infections after infliximab treatment than those who received placebo, and no bronchospasm occurred. One patient had an asymptomatic increase in antinuclear antibody titer after the third infusion of infliximab; otherwise, no significant laboratory changes were observed during the study period.
DISCUSSION
The proinflammatory cytokine TNF- is believed to play a central role in the induction and maintenance of airway inflammation in COPD. In the present study, however, administration of the antieCTNF- drug infliximab to a group of patients with well-characterized COPD did not result in improvement of any of several clinical parameters, including FEV1, CCQ, and quality-of-life indices compared with a control group receiving placebo infusions. Airway inflammation, including percentage of sputum neutrophils and level of IL-8 and REE, also did not change.
One explanation for the lack of response may be that the degree of severity of COPD in our patients was too low to show a significant response. It has been shown that patients with lower FEV1 values have a greater degree of airway inflammation, as reflected by higher levels of sputum neutrophils and IL-8 (10, 31). Because patients with more severe disease are more prone to respiratory tract infections and bronchospasm, we chose to evaluate patients with only mild-to-moderate COPD. We had to take into account the safety and tolerability of infliximab in patients with COPD because this was the first study to evaluate infliximab in the treatment of this condition. Thus, infliximab could possibly prove effective in patients with more severe COPD. Another explanation for the observed lack of clinical response may be that TNF- is not a cytokine that plays a central role in the pathophysiology of COPD, and the observed increase in TNF- is merely an epiphenomenon. There is a wide pleiotrophy and functional redundancy among cytokines, with each function potentially mediated by more than one cytokine (32). Actions attributable to TNF- may in fact be exerted by other cytokines, such as IL-1, IL-8, and IL-6. Other conditions, such as sepsis and heart failure, which are associated with increases in a variety of proinflammatory cytokines, are not mitigated in response to antieCTNF- therapy as well (33, 34).
Lack in observed clinical response could also be related to the study design. All of our patients were current smokers, and it has been shown previously that, at least in patients with Crohn's disease, smoking has a strong adverse effect on the rate and duration of response to infliximab (35). It might also be that the dose of infliximab used was too low, that the duration of our treatment regimen was too short to induce changes in some of our parameters, and/or that follow-up may have been too short to measure significant changes. The same dose of infliximab, however, has produced antiinflammatory and clinical effects within a few weeks in patients with rheumatoid arthritis and Crohn's disease (20, 23). In addition, our study was designed as a pilot study, with a small number of patients and low power to detect changes in our parameters. Finally, it is possible that the sputum parameters we measured may correlate only moderately with inflammatory parameters in lung tissue itself (29).
eNO levels were unexpectedly higher after infliximab treatment than was observed after placebo treatment. Although the change in eNO reached statistical significance, it is of questionable clinical importance, because the median change in eNO was only 2 ppb. Interestingly, an increase in eNO is also observed after smoking cessation (36), suggesting a similar, possibly beneficial mechanism of infliximab treatment in COPD. The significance of this finding is only speculative but could merit further investigation.
Because a higher serum TNF- has been associated with increased energy expenditure in COPD (16), we wanted to see if infliximab would attenuate the REE in our subjects; however, no significant effect was demonstrated. This could be explained by the fact that the REE values for our patients were generally within the normal range at baseline.
No serious adverse events were reported within the 9 weeks of follow-up. Patients did not report more respiratory tract infections after infliximab treatment than those who received placebo, and no bronchospasm occurred in either treatment group. Increased cough was reported by eight patients in the infliximab group, but by none of the patients receiving placebo. Coughing is a frequently reported adverse event after infliximab treatment when given for other diseases, and might be more pronounced in our patient group (37). However, this finding was not supported by the results obtained from the respiratory symptom domains in the CCQ and SGRQ.
In conclusion, our study did not show a short-term improvement in clinical or inflammatory parameters from infliximab treatment in patients with mild-to-moderate COPD, although patients so treated did demonstrate an increase in eNO, a finding of uncertain clinical relevance. Importantly, no severe adverse events occurred and there was no reported increase in the prevalence of respiratory tract infections in 9 weeks of the study. Of patients with COPD who received infliximab, 8 of 14 reported increased coughing, yet this was not reflected in answers to questions about symptoms in the CCQ and SGRQ. Definitive conclusions as to the effectiveness of antieCTNF- treatment in COPD must await additional studies involving patients with COPD with more severe disease, in larger cohorts and with longer follow-up periods.
Acknowledgments
The authors thank M. A. Star-Kroezen and A. J. van der Laan-Boers (Lung Function Department) for the many lung function measurements and sputum inductions they performed and I. Sloots (Laboratory of Pulmonology and Allergology) for all measurements in sputum.
This article has an online supplement, which is accessible from this issue's table of contents at www.atsjournals.org
REFERENCES
van der Vaart H, Koeter GH, Kauffman HF, Postma DS, ten Hacken NHT. The effect of infliximab in patients with chronic obstructive pulmonary disease. Chest 2004;126:840s.
Murray CJ, Lopez AD. Alternative projections of mortality and disability by cause 1990eC2020: Global Burden of Disease Study. Lancet 1997;349:1498eC1504.
Jarvis MJ. Smoking cessation. Eur Respir Rev 1997;7:45:230eC234.
Rutgers SR, Postma DS, Ten Hacken NH, Kauffman HF, van Der Mark TW, Koeter GH, Timens W. Ongoing airway inflammation in patients with COPD who do not currently smoke. Thorax 2000;55:12eC18.
Barnes PJ. Chronic obstructive pulmonary disease: new treatments for COPD. Thorax 2003;58:803eC808.
Churg A, Wang R, Tai H, Wang X, Xie C, Wright J. Tumor necrosis factor- drives 70% of cigarette smoke-induced emphysema in the mouse. Am J Respir Crit Care Med 2004;170:492eC498.
Rahman I, Gilmour PS, Jimenez LA, MacNee W. Oxidative stress and TNF-alpha induce histone acetylation and NF-kappaB/AP-1 activation in alveolar epithelial cells: potential mechanism in gene transcription in lung inflammation. Mol Cell Biochem 2002;234eC235:239eC248.
Mackay F, Loetscher H, Stueber D, Gehr G, Lesslauer W. Tumor necrosis factor alpha (TNF-alpha)-induced cell adhesion to human endothelial cells is under dominant control of one TNF receptor type, TNF-R55. J Exp Med 1993;177:1277eC1286.
Di Francia M, Barbier D, Mege JL, Orehek J. Tumor necrosis factor-alpha levels and weight loss in chronic obstructive pulmonary disease. Am J Respir Crit Care Med 1994;150:1453eC1455.
Keatings VM, Barnes NC. Comparison of inflammatory cytokines in chronic obstructive pulmonary disease, asthma and controls. Eur Respir Rev 1997;7:43:146eC150.
Sakao S, Tatsumi K, Igari H, Shino Y, Shirasawa H, Kuriyama T. Association of tumor necrosis factor alpha gene promoter polymorphism with the presence of chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2001;163:420eC422.
Sakao S, Tatsumi K, Igari H, Watanabe R, Shino Y, Shirasawa H, Kuriyama T. Association of tumor necrosis factor-alpha gene promoter polymorphism with low attenuation areas on high-resolution CT in patients with COPD. Chest 2002;122:416eC420.
Keatings V, Cave S, Henry M, Morgan K, O'Connor C, FitzGerald M, Kalsheker N. A Polymorphism in the tumor necrosis factor- gene promoter region may predispose to a poor prognosis in COPD. Chest 2000;118:971eC975.
Engelen MP, Schols AM, Baken WC, Wesseling GJ, Wouters EF. Nutritional depletion in relation to respiratory and peripheral skeletal muscle function in out-patients with COPD. Eur Respir J 1994;7:1793eC1797.
Schols AM, Buurman WA, Staal van den Brekel AJ, Dentener MA, Wouters EF. Evidence for a relation between metabolic derangements and increased levels of inflammatory mediators in a subgroup of patients with chronic obstructive pulmonary disease. Thorax 1996;51:819eC824.
Nguyen LT, Bedu M, Caillaud D, Beaufrere B, Beaujon G, Vasson M, Coudert J, Ritz P. Increased resting energy expenditure is related to plasma TNF-alpha concentration in stable COPD patients. Clin Nutr 1999;18:269eC274.
De Godoy I, Donahoe M, Calhoun WJ, Mancino J, Rogers RM. Elevated TNF-alpha production by peripheral blood monocytes of weight-losing COPD patients. Am J Respir Crit Care Med 1996;153:633eC637.
Scallon BJ, Moore MA, Trinh H, Knight DM, Ghrayeb J. Chimeric anti-TNF-alpha monoclonal antibody cA2 binds recombinant transmembrane TNF-alpha and activates immune effector functions. Cytokine 1995;7:251eC259.
Knight DM, Trinh H, Le J, Siegel S, Shealy D, McDonough M, Scallon B, Moore MA, Vilcek J, Daddona P. Construction and initial characterization of a mouse-human chimeric anti-TNF antibody. Mol Immunol 1993;30:1443eC1453.
Baert FJ, D'Haens GR, Peeters M, Hiele MI, Schaible TF, Shealy D, Geboes K, Rutgeerts PJ. Tumor necrosis factor alpha antibody (infliximab) therapy profoundly down-regulates the inflammation in Crohn's ileocolitis. Gastroenterology 1999;116:22eC28.
Maini R, St Clair EW, Breedveld F, Furst D, Kalden J, Weisman M, Smolen J, Emery P, Harriman G, Feldmann M, et al. Infliximab (chimeric anti-tumour necrosis factor alpha monoclonal antibody) versus placebo in rheumatoid arthritis patients receiving concomitant methotrexate: a randomised phase III trial. ATTRACT Study Group. Lancet 1999;354:1932eC1939.
Taylor PC, Peters AM, Paleolog E, Chapman PT, Elliott MJ, McCloskey R, Feldmann M, Maini RN. Reduction of chemokine levels and leukocyte traffic to joints by tumor necrosis factor alpha blockade in patients with rheumatoid arthritis. Arthritis Rheum 2000;43:38eC47.
Targan SR, Hanauer SB, van Deventer SJ, Mayer L, Present DH, Braakman T, DeWoody KL, Schaible TF, Rutgeerts PJ. A short-term study of chimeric monoclonal antibody cA2 to tumor necrosis factor alpha for Crohn's disease. Crohn's Disease cA2 Study Group. N Engl J Med 1997;337:1029eC1035.
Van Der Molen T, Willemse BW, Schokker S, Ten Hacken NH, Postma DS, Juniper EF. Development, validity and responsiveness of the Clinical COPD Questionnaire. Health Qual Life Outcomes 2003;1:13.
Quanjer PH, Tammeling GJ, Cotes JE, Pedersen OF, Peslin R, Yernault JC. Lung volumes and forced ventilatory flows. Report Working Party Standardization of Lung Function Tests, European Community for Steel and Coal. Official Statement of the European Respiratory Society. Eur Respir J Suppl 1993;16:5eC40.
Rutgers SR, Timens W, Tzanakis N, Kauffman HF, van der Mark TW, Koeter GH, Postma DS. Airway inflammation and hyperresponsiveness to adenosine 5'-monophosphate in chronic obstructive pulmonary disease. Clin Exp Allergy 2000;30:657eC662.
Baarends EM, Schols AM, Pannemans DL, Westerterp KR, Wouters EF. Total free living energy expenditure in patients with severe chronic obstructive pulmonary disease. Am J Respir Crit Care Med 1997;155:549eC554.
American Thoracic Society. Recommendations for standardized procedures for the on-line and off-line measurement of exhaled lower respiratory nitric oxide and nasal nitric oxide in adults and children—1999. Am J Respir Crit Care Med 1999;160:2104eC2117.
Rutgers SR, Timens W, Kauffman HF, van der Mark TW, Koeter GH, Postma DS. Comparison of induced sputum with bronchial wash, bronchoalveolar lavage and bronchial biopsies in COPD. Eur Respir J 2000;15:109eC115.
Suri R, Marshall LJ, Wallis C, Metcalfe C, Bush A, Shute J. Effects of recombinant human DNase and hypertonic saline on airway inflammation in children with cystic fibrosis. Am J Respir Crit Care Med 2002;166:352eC355.
Vernooy JH, Kucukaycan M, Jacobs JA, Chavannes NH, Buurman WA, Dentener MA, Wouters EF. Local and systemic inflammation in patients with chronic obstructive pulmonary disease: soluble tumor necrosis factor receptors are increased in sputum. Am J Respir Crit Care Med 2002;166:1218eC1224.
Chung KF. Cytokines in chronic obstructive pulmonary disease. Eur Respir J Suppl 2001;34:50seC59s.
Chung ES, Packer M, Lo KH, Fasanmade AA, Willerson JT. Randomized, double-blind, placebo-controlled, pilot trial of infliximab, a chimeric monoclonal antibody to tumor necrosis factor-alpha, in patients with moderate-to-severe heart failure: results of the anti-TNF Therapy Against Congestive Heart Failure (ATTACH) trial. Circulation 2003;107:3133eC3140.
Clark MA, Plank LD, Connolly AB, Streat SJ, Hill AA, Gupta R, Monk DN, Shenkin A, Hill GL. Effect of a chimeric antibody to tumor necrosis factor-alpha on cytokine and physiologic responses in patients with severe sepsis: a randomized, clinical trial. Crit Care Med 1998;26:1650eC1659.
Arnott ID, McNeill G, Satsangi J. An analysis of factors influencing short-term and sustained response to infliximab treatment for Crohn's disease. Aliment Pharmacol Ther 2003;17:1451eC1457.
Robbins RA, Millatmal T, Lassi K, Rennard S, Daughton D. Smoking cessation is associated with an increase in exhaled nitric oxide. Chest 1997;112:313eC318.
Keating GM, Perry CM. Infliximab: an updated review of its use in Crohn's disease and rheumatoid arthritis. BioDrugs 2002;16:111eC148.