Targeting systemic inflammation: novel therapies for the treatment of chronic obstructive pulmonary disease

Multidimensional approach for the proper management of a complex chronic patient with chronic obstructive pulmonary disease

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is frequently associated with comorbidities occurring either independently or as consequences of COPD. Areas covered: This review examines the interactions between the pathophysiology of COPD and the most frequent comorbidities, and highlights the need for multidimensional clinical strategies to manage COPD patients with comorbidities. Expert commentary: Most COPD patients need to be approached in a complex and multifactorial scenario. The diagnosis of COPD is necessarily based on the presence of chronic respiratory symptoms and poorly reversible airflow obstruction, but exacerbations and comorbidities need to be considered in the evaluation of disease severity and prognosis in individual patients. More importantly, defining the precise relationship between COPD and comorbidities for each patient is the basis for a correct therapeutic approach.

Association Between Statin Medications and COPD-Specific Outcomes: A Real-World Observational Study

Background

Disease-modifying drugs are not yet available for the management of chronic obstructive pulmonary disease (COPD). HMG-CoA reductase inhibitors (statins) have anti-inflammatory properties and are therefore being considered for use in the management of COPD.

Objective

Our objective was to examine the association between statin use and COPD-specific outcomes in a real-world setting.

Methods

This was a retrospective longitudinal dynamic cohort study that used Medicaid claims data from multiple years (2005–2008) to identify patients with newly diagnosed COPD. Statin therapy was determined from the prescription drug file using National Drug Codes (NDCs). COPD-specific outcomes such as hospitalizations and emergency room and outpatient visits were identified based on a primary diagnosis of COPD. Multivariable logistic regressions with inverse probability treatment weights (IPTWs) were used to examine the relationship between statin therapy and COPD-specific outcomes.

Results

The study included 19,060 Medicaid beneficiaries with newly diagnosed COPD, 30.3% of whom received statins during the baseline period. Adults who received statins had significantly lower rates of COPD-specific hospitalizations (4.7 vs. 5.2%; p < 0.05), emergency room visits (13.4 vs. 15.4%; p < 0.001), and outpatient visits (41.4 vs. 44.7%; p < 0.001) than those who did not receive statin therapy. Even after adjusting for observed selection bias with IPTWs, adults receiving statins were less likely to have COPD-specific hospitalizations [adjusted odds ratio (AOR) 0.76; 95% confidence interval (CI) 0.66–0.87], emergency room visits (AOR 0.81; 95% CI 0.75–0.89), and outpatient visits (AOR 0.86; 95% CI 0.80–0.91) than those not receiving statins.

Conclusions

Findings from this study suggest statins have beneficial effects in patients with newly diagnosed COPD and warrant further clinical trial investigation.

The effect of vitamin D on COPD exacerbation: a double blind randomized placebo-controlled parallel clinical trial

Background

To investigate the effect of supplementation of standard treatment (inhaled long-acting β2 agonists, anticholinergics and corticosteroids) with vitamin D on C reactive protein and pulmonary function tests in patients with COPD exacerbation.

Methods

Design: Randomized, single-center, double-blind, placebo-controlled parallel trial. One teaching hospital Participants: 135 patients in pulmonary ward with moderate to severe COPD and exacerbations.120 patients fulfilled the study protocol. Interventions: Patients were randomly divided into three groups receiving 7 day treatment with 0.25 μg calcitriol daily (n = 45), 50000 IU daily of vitamin D (n = 45) or placebo (n = 45). An independent nurse was responsible for allocation, preparation, and accounting of trial medications. Main Outcome measures: Maximal expiratory flow volume (FEV1) and forced volume capacity curves (FVC) and Modified Medical Research Council (MMRC) scale.

Results

Out of 135 patients who were recruited consecutively, 45 patients randomly were randomly assigned in three groups (balance blocked randomization.15 patients were dropped out due to non-compliance for second PFT. Intention to treat analysis was carried out for 120 participants. The difference between before and after treatment FEV1 and FEV1/FVC ratio had no significant difference between treatment groups and placebo. (P = 0.43, P = 0.51, respectively)but clinical improvement was significant in patients who received calcitriol. No side effects were reported.

Conclusions

Short term treatment with either calcitriol or 25(OH) ₂Vit D didn’t changed FEV1 or FVC in vitamin D sufficient patients with COPD exacerbation; nevertheless it can provide clinical benefit.

Trial registration

Trial registration: Iranian Registry of Clinical Trials no. IRCT138712271774N1. Registered 10 April 2011.

Prevention of acute exacerbations of COPD: American College of Chest Physicians and Canadian Thoracic Society Guideline

BACKGROUND

COPD is a major cause of morbidity and mortality in the United States as well as throughout the rest of the world. An exacerbation of COPD (periodic escalations of symptoms of cough, dyspnea, and sputum production) is a major contributor to worsening lung function, impairment in quality of life, need for urgent care or hospitalization, and cost of care in COPD. Research conducted over the past decade has contributed much to our current understanding of the pathogenesis and treatment of COPD. Additionally, an evolving literature has accumulated about the prevention of acute exacerbations.

METHODS

In recognition of the importance of preventing exacerbations in patients with COPD, the American College of Chest Physicians (CHEST) and Canadian Thoracic Society (CTS) joint evidence-based guideline (AECOPD Guideline) was developed to provide a practical, clinically useful document to describe the current state of knowledge regarding the prevention of acute exacerbations according to major categories of prevention therapies. Three key clinical questions developed using the PICO (population, intervention, comparator, and outcome) format addressed the prevention of acute exacerbations of COPD: nonpharmacologic therapies, inhaled therapies, and oral therapies. We used recognized document evaluation tools to assess and choose the most appropriate studies and to extract meaningful data and grade the level of evidence to support the recommendations in each PICO question in a balanced and unbiased fashion.

RESULTS

The AECOPD Guideline is unique not only for its topic, the prevention of acute exacerbations of COPD, but also for the first-in-kind partnership between two of the largest thoracic societies in North America. The CHEST Guidelines Oversight Committee in partnership with the CTS COPD Clinical Assembly launched this project with the objective that a systematic review and critical evaluation of the published literature by clinical experts and researchers in the field of COPD would lead to a series of recommendations to assist clinicians in their management of the patient with COPD.

CONCLUSIONS

This guideline is unique because it provides an up-to-date, rigorous, evidence-based analysis of current randomized controlled trial data regarding the prevention of COPD exacerbations.

Statin use in COPD patients is associated with a reduction in mortality: a national cohort study

AIMS

To assess whether statin use is associated with reduced mortality in patients with chronic obstructive pulmonary disease (COPD).

METHODS

Hospitalisation, drug dispensing, and mortality records were linked for New Zealanders aged 50-80 years discharged from hospital with a first admission with COPD in 2006. Patients were classified according to whether or not they were prescribed statins prior to admission. Baseline characteristics were compared and hazard ratios calculated for statin users versus statin non-users for all-cause mortality over follow-up of up to 4 years.

RESULTS

A total of 1,687 patients (mean age 70.6 years) were followed, including 596 statin users and 1,091 non-users. There were more men in the statin user group (58.4% vs. 48.5%), and statin users were more likely to have a history of cardiovascular disease (58.6% vs. 25.1%), prescription for frusemide as a proxy for heart failure (47.7% vs. 24.5%) or diabetes (35.4% vs.11.6%) than statin non-users (p<0.001). A total of 671 deaths occurred during the follow-up period. After adjustment for age, sex, ethnic group, history of cardiovascular disease, diabetes, and prescription for frusemide, the hazard ratio for statin users vs. statin non-users for all-cause mortality was 0.69 (95% CI 0.58 to 0.84).

CONCLUSIONS

Statin use is associated with a 30% reduction in all-cause mortality at 3-4 years after first admission for COPD, irrespective of a past history of cardiovascular disease and diabetes.

Treatment of COPD: moving beyond the lungs

We still do not know whether the successful treatment of the comorbid diseases associated with COPD, mainly cardiovascular disease, also positively influences the course of the lung disease because so far there are few definite data documenting that treatment of COPD comorbidities will reduce morbidity and mortality rates in these patients. Observational studies suggest that COPD patients treated with statins, angiotensin-converting enzyme inhibitors and angiotensin II type 1 receptor blockers, and β-adrenoceptor blockers may have improved survival and reduced hospitalisation from exacerbations. Progress in basic and translational research has led to a better understanding of pharmacological mechanisms that may explain the effects of these drugs on COPD and some small clinical trial activity is beginning to generate promising results.

Targeting inflammation to slow or delay functional decline: where are we?

The role of inflammation in the pathophysiology of chronic age-related diseases is increasingly recognized, and inflammation could represent the common pathway linking diseases and disability. Thus, targeting inflammation could represent a useful strategy at preventing or delaying functional decline. In this paper we review recent evidence suggesting that selected drugs, such as statins, fibrates, angiotensin converting enzyme-inhibitors and angiotensin receptor blockers, and physical exercise may be able to contrast functional decline by blunting inflammation. Results from randomized trials investigating the effects of physical activity programs on inflammation and functional decline is still limited, and further investigations are warranted.

Vitamin D beyond bones in chronic obstructive pulmonary disease: time to act

The discovery that the vitamin D endocrine system regulates a very large number of genes and their associated biological processes improves our insight into the fundamental role of vitamin D and sun exposure for human health. Accumulating epidemiological data are linking a low vitamin D nutritional status to highly prevalent diseases such as cancer, autoimmune diseases, and chronic infections. Approximately half of the world's elderly, and to a lesser extent the adult population, have insufficient to deficient 25-hydroxyvitamin D (25-OHD) serum levels, and several intervention studies are being undertaken to study the impact of adequate vitamin D supplementation in chronic diseases. In this perspective we claim that chronic obstructive pulmonary disease (COPD) is a candidate disease for which vitamin D supplementation might be beneficial. Epidemiological studies revealed a dose-dependent association between serum 25-OHD levels and pulmonary function so that adequate vitamin D supplementation may extend beyond its protection against osteoporotic fractures. In line with the novel insights on its immune function, it is tempting to speculate that vitamin D may down-regulate the inflammatory immune response in the airways while boosting innate immune defense against different microorganisms. Apart from its affects on osteoporosis, vitamin D may also interfere with other comorbidities of COPD such as skeletal muscle weakness, cardiovascular disease, and cancer. Because respiratory treatments in COPD fail to reverse disease progression, interventional trials that may exploit the broader potential of vitamin D are warranted. A further challenge of such studies is to define optimal serum 25-OHD levels for such noncalcemic endpoints.

Delivery strategies to target therapies to inflammatory tissue

BACKGROUND

Inflammation plays a key role in many chronic disease processes as well as an acute role in injury and wound healing. Various cell types are recruited from the bloodstream to the inflamed site through adhesion molecules, cytokines, chemokines and others.

OBJECTIVES

This review examines many drug-targeting strategies that make use of these molecules or signaling pathways, and seeks to describe certain commonalities irrespective of the disease process or agent to be delivered.

METHODS

A survey of the literature, primarily within the last year, was performed. Search words included 'drug targeting' and 'inflammation' and of those, the scope was refined to include those studies that specifically sought to modify or ameliorate an aspect of the inflammatory process in the treatment of a disease.

RESULTS/CONCLUSION

Inflammation plays a key role in many diseases, and many similar targets (such as adhesion molecules) are the focus of the treatment of those diseases.

A physiological function for apolipoprotein(a): a natural regulator of the inflammatory response

Structural similarities between apolipoprotein(a) (apo(a)), the unique apoprotein of lipoprotein(a), and plasminogen, the zymogen of plasmin, can interfere with functions of plasmin (ogen) in vitro. The purpose of this study was to evaluate the role of apo(a) in inflammation in vivo using apo(a) transgenic mice and to determine if effects are plasminogen-dependent using backgrounds that are either plasminogen-replete or plasminogen-deficient. After administration of peritoneal inflammatory stimuli, thioglycollate, bioimplants or lipopolysaccharide, the number of responding peritoneal neutrophils and macrophages were quantified. Apo(a), in either wild-type or plasminogen deficient backgrounds, inhibited neutrophil recruitment but had no effect on plasminogen-dependent macrophage recruitment. Macrophage-inflammatory protein-2, a neutrophil chemokine, was reduced in apo(a) mice, and injection of this chemokine prior to thioglycollate restored neutrophil recruitment in apo(a) transgenic mice. In the lipopolysaccharide model, mice with apo(a), unlike mice without apo(a), did not increase neutrophil recruitment in response to the stimulus. In the bioimplant model, neutrophil recruitment and neutrophil cytokines were reduced in apo(a)tg mice but only in a plasminogen-deficient background. These results indicate for the first time that apo(a), independent of plasminogen interaction, inhibits neutrophil recruitment in vivo in diverse peritoneal inflammatory models. Hence, apo(a) may function as a cell specific suppressor of the inflammatory response.

Targeting histone deacetylases for the treatment of disease

The ‘histone code’ is a well-established hypothesis describing the idea that specific patterns of post-translational modifications to histones act like a molecular ‘code’ recognized and used by non-histone proteins to regulate specific chromatin functions. One modification, which has received significant attention, is that of histone acetylation. The enzymes that regulate this modification are described as lysine acetyltransferases or KATs, and histone deacetylases or HDACs. Due to their conserved catalytic domain HDACs have been actively targeted as a therapeutic target. The pro-inflammatory environment is increasingly being recognized as a critical element for both degenerative diseases and cancer. The present review will discuss the current knowledge surrounding the clinical potential and current development of histone deacetylases for the treatment of diseases for which a pro-inflammatory environment plays important roles, and the molecular mechanisms by which such inhibitors may play important functions in modulating the pro-inflammatory environment.

Purinergic regulation of neutrophil chemotaxis

Chemotaxis allows polymorphonuclear neutrophils (PMN) to rapidly reach infected and inflamed sites. However, excessive influx of PMN damages host tissues. Better knowledge of the mechanisms that control PMN chemotaxis may lead to improved treatments of inflammatory diseases. Recent findings suggest that ATP and adenosine are involved in PMN chemotaxis. Therefore, these purinergic signaling processes may be suitable targets for novel therapeutic approaches to ameliorate host tissue damage.