Tissue-type plasminogen activator and plasminogen activator inhibitor type 1 as compared to lower extremity artery disease.
Abstract Background Chronic lower extremity artery disease (LEAD) involves progressive arterial narrowing manifested by intermittent claudication (IC). LEAD entails endothelial dysfunction and fibrinolytic disorders. The main objective of the present study was to analyze selected parameters of the fibrinolytic system in the blood of patients with symptomatic LEAD depending on clinical parameters. Methods The test group consisted of 80 patients with LEAD (27F/53M) with an average age of 63.5±9 years. The control group included 30 healthy, non-smoking volunteers (10F/20M), with their median age of 56±6 years. The research material comprised venous blood to determine concentrations of tissue-type plasminogen activator (t-PA Ag), plasminogen activator inhibitor type 1 (PAI-1 Ag) and D-dimer, fibrinogen and platelet count (PLT). Results Elevated concentrations of t-PA Ag and PAI-1 Ag as well as D-dimer and fibrinogen were found in the plasma of subjects with symptomatic LEAD. Various stages of the Fontaine classification demonstrated a gradual, statistically significant increase in the concentrations of fibrinogen and PLT count as the disease progressed. The subgroup of LEAD patients aged ≥ 65 years was reported to have significantly higher levels of D-dimer than the group of younger subjects. Besides, the LEAD group demonstrated: negative correlations between IC distance and fibrinogen concentrations, and PLT count, negative correlations between ABI at rest and concentrations of D-dimer and PLT count, and positive correlations between age and D-dimer levels. Conclusion High t-PA Ag concentrations in LEAD patients reflect damaged endothelium which comprises the main source of this factor. With high PAI-1 Ag levels, inactive fibrinolytic t-PA-PAI-1 complexes are formed. Increasing fibrinogen concentrations at the subsequent stages in accordance with the Fontaine classification, suggest a growing inflammatory condition. Elevated values of D-dimer reflect the aggregation of secondary fibrinolysis activation as the patient ages and along with impaired extremity vascularization manifested by the decreasing ABI.