Plasma Fibrinogen as a Biomarker of Stable and Exacerbated Chronic Obstructive Pulmonary Disease

An experimental, comparative, cross-sectional study

Department of Physiology, Federal Post Graduate Medical Institute (FPGMI), Sheikh Zayed Medical Complex Lahore, Pakistan from August 2013 to 2014

Chronic Obstructive Pulmonary Disease (COPD) is a preventable and treatable disease, but is a partially reversible chronic inflammatory condition characterized by airway obstruction. COPD remains under-diagnosed and under-treated because the only available diagnostic method at present is testing lung functions by spirometry which is not helpful to determine the severity and clinical outcomes of the disease. Circulating biomarkers are under consideration for various diseases worldwide. Plasma fibrinogen is emerging as one of the most promising biomarkers of COPD in smokers.

The objective of this study is to investigate if plasma fibrinogen can serve as a diagnostic biomarker of COPD in smokers, and if its further higher levels are seen in the exacerbated state of the disease in comparison to the stable disease.

75 middle-aged to old-age smokers of either gender were selected. Lung functions of every participant were measured to determine Forced Expiratory Volume in the first second (FEV1), Forced Vital Capacity (FVC), and the ratio of FEV1/FVC by spirometry. On the basis of the results of the tests, subjects were divided into three groups; firstly, the control group of chronic smokers without COPD, secondly, smokers with COPD in a stable state, and thirdly, patients in an exacerbated state of COPD. Plasma fibrinogen was quantitatively estimated in every individual of all three groups by the Clauss method using the Hemostat Fibrinogen kit.

The average Plasma fibrinogen level was found to be 235.008 mg/dl in healthy smokers (control group), while an average of 440.12mg/dl was measured in patients with stable COPD. The difference in plasma fibrinogen levels was found to be significant, having a p-value of (0.000). In the third group with declined lung function predicting acute exacerbated COPD, fibrinogen was found to be > 453.2 mg/dl, which was significantly higher than in the stable disease group (p-value > 0.0017)

Plasma fibrinogen level measurement is a reliable and accessible test in terms of a diagnostic marker of COPD, as compared to conventional lung function testing done in the past.