Impact of Fibrinogen-β Chain Polymorphism (rs4220), Plasma Fibrinogen and Thrombin-Antithrombin Complex in Iraqi Patients with Coronary Artery Disease

Abstract

Objective: To measure the concentration of plasma thrombin-antithrombin complex and fibrinogen, and to analyze the single-nucleotide polymorphism of the fibrinogen B gene (rs4220) in Iraqi coronary artery disease patients and healthy controls

Study Design: Case-control study
Place and Duration of Study: This study was conducted at the Ibn Al-Nafees Hospital, Baghdad Governorate, Iraq, from 1st December 2025 to 28th February 2026.

Methodology: One hundred and twenty participants were enrolled, 40 patients with both diabetes mellitus and coronary artery disease (GI), 40 patients with coronary artery disease only (GII), and 40 apparently healthy controls (GIII). An enzyme-linked immunosorbent assay is used to quantify P. fibrinogen and thrombin-antithrombin complex concentrations. The deoxyribonucleic acid was isolated from blood, followed by polymerase chain reaction amplification using a thermocycler and a newly designed pair of primers targeting the fibrinogen B gene. The Sanger sequencing technique detected the rs4220 single-nucleotide polymorphism.

Results: The highly significant difference in plasma fibrinogen and thrombin-antithrombin complex concentrations compared with controls (P< 0.01). The genotypes (P<0.01) of the rs4220 single-nucleotide polymorphism in the fibrinogen B gene differed significantly between coronary artery disease patients with diabetes mellitus and controls; no significant difference was observed between the coronary artery disease patients without diabetes mellitus and controls (P=0.061). The allele frequencies (P<0.01) differed significantly between the G1 and GIII.

Conclusion: The rs4220 polymorphism in the fibrinogen B gene is associated with an increased risk of coronary artery disease and help to assess the genetic risk and inform effective prevention strategies in Iraq.