Inflammatory biomarkers improve the clinical prediction of mortality in COPD

March 16, 2012

The addition of changes in inflammatory biomarkers to established clinical variables improves the prediction of mortality in patients with chronic obstructive pulmonary disease (COPD), according to a new study.

"COPD is characterized by low-grade inflammation, so we hypothesized that the addition of inflammatory biomarkers to established predictive factors would improve the prediction of mortality," said lead author Bartolome Celli, lecturer in medicine at Harvard Medical School and member of the Pulmonary and Critical Care Division of Brigham and Women's Hospital in Boston. "We found that the addition of a panel of selected biomarkers to clinical variables significantly improved the ability of clinical variables to predict mortality in these patients."

The findings were published online ahead of print publication in the American Thoracic Society's American Journal of Respiratory and .

The researchers analyzed prospectively collected data on 1,843 COPD patients from the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) study. Of these 1,843 patients, 168 (9.1%) died during the three-year follow-up.

Clinical predictors of morality included age, BODE (Body-Mass Index, , Dyspnea, and Exercise Capacity) index , and incidence of hospitalizations due to exacerbations of COPD in the year prior to the study. A predictive model for mortality using these clinical variables had a C-statistic (which measures the ability of how well a clinical prediction rule can correctly rank-order patients by risk) of 0.686. Adding interleukin-6 (IL-6) to the predictive model significantly improved the C-statistic to 0.708, and the addition of a panel of biomarkers including white blood cell counts, IL-6, C-reactive protein (CRP), interleukin-8 (IL-8), fibrinogen, chemokine (C-C-motif) ligand 18 (CCL-18), and surfactant protein D (SP-D) further improved the C-statistic to 0.726.

"This panel of selected biomarkers was not only elevated in non-survivors in our cohort, but was associated with mortality over three years of follow-up after adjusting for clinical variables known to predict mortality in patients with COPD," said Dr. Celli. "Except for IL-6, these biomarkers improved the predictive value of our model only marginally when considered individually, but they improved the model significantly when analyzed as a group."

The study had several limitations, including the lack of a study adjudication committee to specify causes of death, the exclusion of some biomarkers thought to be important in the pathobiology of COPD, and the lack of a validating cohort.

"Adding white blood cell counts and measurement of changes in systemic levels of IL-6, CRP, IL-8, fibrinogen, CCL-18, and SP-D significantly improves the ability of clinical variables to predict mortality in patients with COPD," said Dr. Celli. "This is the first study to show that the addition of biomarker levels to clinical predictors in COPD adds relevant prognostic information."

Explore further: New tool to predict the risk of death in COPD

Related Stories

New tool to predict the risk of death in COPD

August 28, 2009

Researchers have developed an index scale to help physicians predict a patient's risk of dying from chronic obstructive pulmonary disease (COPD). The ADO index can help physicians assess the severity of a patient's illness ...

Researchers link novel biomarkers to asthma and COPD

March 11, 2011

Four novel biomarkers have been identified which may aid in the diagnosis and management of asthma and chronic obstructive pulmonary disease (COPD), according to a study conducted by researchers in Australia, who determined ...

Study confirms link between rheumatoid arthritis and COPD

May 26, 2011

Patients with rheumatoid arthritis are two times more likely to have concurrent chronic obstructive pulmonary disease (COPD) than healthy controls -- an association which was sustained even when variables such as age, gender, ...

Recommended for you

Team discovers how Zika virus causes fetal brain damage

August 24, 2016

Infection by the Zika virus diverts a key protein necessary for neural cell division in the developing human fetus, thereby causing the birth defect microcephaly, a team of Yale scientists reported Aug. 24 in the journal ...

Zika infection may affect adult brain cells

August 18, 2016

Concerns over the Zika virus have focused on pregnant women due to mounting evidence that it causes brain abnormalities in developing fetuses. However, new research in mice from scientists at The Rockefeller University and ...

Immune breakthrough: Unscratching poison ivy's rash

August 23, 2016

We all know that a brush with poison ivy leaves us with an itchy painful rash. Now, Monash University and Harvard researchers have discovered the molecular cause of this irritation. The finding brings us a step closer to ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.