en Pulmonary Disease Pulmonary Disease Original Research Original Research <p> <strong> Background </strong>:Chronic obstructive pulmonary disease (COPD) is a third leading cause of death. </p><p> <strong> Methods </strong>: In this case control study, we prepared 5 cc bloods from the antecubital vein of 100 COPD patients and 40 healthy individuals as control group. Vascular endothelial growth factor (VEGF) expression protein level was measured by ELISA in both groups. </p><p> <strong> Results </strong>: We found that concentration of VEGF in blood serum of patients with COPD (189.9±16pg/ml) was significantly higher than the control group (16.4±3.48pg/ml) (p<0.001). While VEGF serum level in emphysematous patients wasn’t significantly different with control group (p=0.07). Furthermore VEGF serum level in COPD patients was proportionally increased with severity of disease (p<0.001). Besides all COPD patients, regardless of their smoking status, were experienced significantly higher levels of VEGF than healthy ones (p=0.001 z=4.3). </p><p> <strong> Conclusion </strong>: Our results suggest VEGF serum concentration as the sensitive index for severity and activity of COPD and its prognosis. </p> Chronic obstructive pulmonary disease, Vascular Endothelial Growth Factor, Chronic bronchitis, Emphysema. 539 544 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-1-717&slc_lang=en&sid=1 Reza Farid Hosseini Rfarid@gmail.com 200319475328460012644 200319475328460012644 No Allergy Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. Farahzad Jabbari Azad Jabbarif@mums.ac.ir 200319475328460012645 200319475328460012645 No Allergy Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. Hadis Yousefzadeh yousefzadehh901@mums.ac.ir 200319475328460012646 200319475328460012646 No Immunology Research Center, Bu-Ali Research Institute, Student Research Committee, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. Houshang Rafatpanah rafatpanahh@mums.ac.ir 200319475328460012647 200319475328460012647 No Inflammation and Inflammatory Disease Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. Saeed Hafizi Saeed.hafizi@yahoo.com 200319475328460012648 200319475328460012648 No Shariati Hospital, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. Homan Tehrani hmnthp@gmail.com 200319475328460012649 200319475328460012649 No School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. Masoud Khani arc@mums.ac.ir 200319475328460012650 200319475328460012650 Yes Mashhad University of Medical Sciences, Mashhad, Iran.