Increased systemic inflammation is a risk factor for COPD exacerbations.

BACKGROUND: COPD is characterized by episodic increases in respiratory symptoms, so-called exacerbations. COPD exacerbations are associated with an increase in local and systemic inflammation. Data of a previously published study in a well-characterized COPD cohort were analyzed to define predictive factors of acute exacerbations, particularly focusing on systemic inflammation. OBJECTIVE: To determine if an elevated systemic inflammatory status measured at baseline is related to the occurrence of acute exacerbations in patients with COPD. METHODS: The occurrence of moderate (requiring oral prednisolone) and severe exacerbations (requiring hospitalization) was prospectively recorded over 1 year. At the beginning of the study, lung function values (FEV1, FVC, functional residual capacity, and diffusion capacity of the lung for carbon monoxide [Dlco]) and serum levels of C-reactive protein, fibrinogen, lipopolysaccharide binding protein, tumor necrosis factor (TNF)-alpha, and its soluble receptors (soluble TNF receptors 55 and 75) as markers of systemic inflammation were determined. RESULTS: Two hundred seventy-seven person-years of follow-up were analyzed in the total group of 314 patients: 186 patients were responsible for 411 exacerbations (374 moderate and 37 severe). Multivariate analyses showed that a higher initial fibrinogen level and a lower FEV1 predicted a higher rate of both moderate and severe exacerbations. Additional independent predictors of a severe exacerbation were a higher number of prestudy severe exacerbations and lower Dlco. A higher number of prestudy moderate exacerbations was the only additional independent risk factor for the rate of moderate exacerbations. CONCLUSION: This study demonstrates that besides lung function impairment systemic inflammation manifested by elevated fibrinogen levels is an independent risk factor for exacerbations of COPD. Attenuation of systemic inflammation may offer new perspectives in the management of COPD patients to reduce the burden of exacerbations.

Longitudinal follow-up of systemic inflammation after acute exacerbations of COPD.

BACKGROUND: Acute exacerbations are important in the clinical course of COPD, yet the underlying mechanisms are poorly understood. Systemic inflammation is now considered as an important component in the disease process. In this study we evaluated longitudinally the systemic inflammation during hospital treatment for acute exacerbation and after clinical recovery. METHODS: Blood was collected on day 0, 1, 4 and 8 in 21 patients admitted for an acute exacerbation of COPD and at 1 month, 3 months and 6 months after discharge. Systemic inflammation was determined by measurement of the pro-inflammatory markers interleukin (IL)-6, soluble tumor necrosis factor (TNF) receptors sTNFR55 and sTNFR75, the anti-inflammatory mediator sIL-1RII, and bactericidal permeability increasing protein (BPI) as a marker of neutrophil activation. In addition, plasma level of Trolox antioxidant capacity (TEAC) was determined. Healthy age-matched controls were measured for the same markers at one time-point. RESULTS: All inflammatory markers analyzed were elevated on first day of admission for exacerbation of COPD, as compared to healthy controls. During treatment, levels of IL-6, and sTNFR75 rapidly decreased, whereas sTNFR55 and BPI remained elevated. Moreover, sIL-1RII and TEAC increased during first 8 days of treatment. In the stable condition all inflammatory markers returned to values comparable to healthy controls, with the exception of BPI, which remained persistently elevated compared to healthy controls. CONCLUSION: This study clearly demonstrates upregulation of systemic inflammation in acute exacerbations of COPD. Attenuation of systemic inflammation may offer new perspectives in the management of COPD patients to reduce the burden of exacerbations.

Mortality and mortality-related factors after hospitalization for acute exacerbation of COPD.

BACKGROUND: Acute exacerbations form a major component of the socioeconomic burden of COPD. As yet, little information is available about the long-term outcome of patients who have been hospitalized with acute exacerbations, although high mortality rates have been reported. STUDY OBJECTIVE: The aim of this study was to investigate prospectively the outcome for all patients admitted to the hospital with acute exacerbations of COPD during hospital admission and after 1-year of follow-up. Furthermore, patient characteristics related to increased mortality rate were analyzed. DESIGN: We investigated prospectively the 1-year mortality rate and potential determinants of mortality for all patients admitted to the hospital with an acute exacerbation between January 1 and December 31, 1999. RESULTS: A total of 171 patients were included in the study. The mortality rate during hospital stay was 8%, increasing to 23% after 1 year of follow-up. Despite a comparable in-hospital mortality rate (6%), the 1-year mortality rate was significantly higher for patients admitted to the ICU for respiratory failure (35%). The multivariate Cox proportional hazards model was used to determine independent predictors of survival. Variables included in the regression model were age, sex, FEV(1), PaO(2), PaCO(2), body mass index, long-term use of oral corticosteroids, comorbidity index, and hospital readmissions. The maintenance use of oral glucocorticosteroids (relative risk [RR], 5.07; 95% confidence interval [CI], 2.03 to 12.64), PaCO(2) (RR, 1.17; 95% CI, 1.01 to 1.38), and age (RR, 1.07; 95% CI, 1.01 to 1.12) were independently related to mortality. CONCLUSION: We conclude that the prognosis for patients who have been admitted to the hospital for acute exacerbation of COPD is poor. Long-term use of oral corticosteroids, higher PaCO(2), and older age could be identified as risk factors associated with higher mortality.

Bacterial infections in patients requiring admission for an acute exacerbation of COPD; a 1-year prospective study.

STUDY OBJECTIVE: To investigate the frequency of respiratory bacterial infections in hospitalized patients, admitted with an acute exacerbation of chronic obstructive pulmonary disease (COPD), to identify the responsible pathogens by sputum culture and to assess patient characteristics in relation to sputum culture results. METHODS: We prospectively evaluated clinical data and sputum culture results of 171 patients, admitted to the pulmonology department of the University Hospital Maastricht with an acute exacerbation of COPD from 1st January 1999 until 31st December 1999. RESULTS: Eighty-five patients (50%) had positive sputum cultures, indicating the presence of bacterial infection. Pathogens most frequently isolated were: Haemophilus influenzae (45%), Streptococcus pneumoniae (27%), and Pseudomonas aeruginosa (15%). Patients with more severely compromised lung function had a higher incidence of bacterial infections (P = 0.026). There were no significant differences in age, lung function parameters, blood gas results and length of hospital stay between patients with and without bacterial infection. There were no correlations between the type of bacteria isolated and clinical characteristics. CONCLUSION: Incidence of bacterial infection during acute exacerbations of COPD is about 50%. Patients with and without bacterial infection are not different in clinical characteristics or in outcome parameters. Patients with lower FEV1 have a higher incidence of bacterial infections, but there is no difference in the type of bacterial infection. In the future, the pathogenic role of bacterial infection in exacerbations of COPD should be further investigated, especially the role of bacterial infection in relation to local and systemic inflammation.

Systemic inflammation in chronic obstructive pulmonary disease: the role of exacerbations.

The systemic manifestations of chronic obstructive pulmonary disease (COPD) exacerbations are recognized, but our understanding of their etiology and importance is lacking largely due to the small number of systematic and longitudinal studies. Most of the systemic manifestations are likely the result of inflammatory processes. Serum biomarkers, such as various cytokines, adipokines, C-reactive protein, and coagulation factors, are elevated during exacerbations. Our understanding of the systemic manifestations can be greatly enhanced if we integrate what is known about the basic science of systemic mediators with the translational science of their role in COPD exacerbations. Many overlapping connections and promising avenues of future research come to light with such a viewpoint.