Endothelial Microparticles and Blood Coagulation Activation in Head and Neck Cancer Patients Undergoing Radiotherapy or Radiochemotherapy

Abstract

Background/aim: Endothelial microparticles (EMP) are small vesicles which are released from the endothelium and contribute to blood coagulation activation in various clinical settings. The aim of this study was to examine whether EMP influence blood coagulation activation in cancer patients during radiotherapy/radiochemotherapy (RT/RCT).

Materials and methods: Sixteen head and neck cancer (HNC) patients undergoing RT/RCT and 10 controls were examined. EMP and thrombin-antithrombin complex (TAT) were measured by flow cytometry and enzyme-linked immunosorbent assay (ELISA), respectively. Tissue factor-positive EMP (TF⁺EMP) were defined as CD31⁺/CD142⁺/CD42b^- Results: TF⁺EMP were significantly elevated in HNC patients before RT/RCT (T₀) (1299±1154/μl), one day after RT/RCT (T_1d) (1257±603/μl) and 3 months after RT/RCT (T_3m) (1289±372/μl) compared to controls (688±647/μl). TF⁺EMP levels at T₀/T_1d and T₀, as well as at T_1d and T_3m were not significantly different. TAT levels at T₀ and T_1d did not differ significantly but at T_3m were significantly lower compared to T₀ and T_1d TF⁺EMP and TAT concentrations were not significantly correlated at T₀ (r=0.058; p=0.828), T_1d (r=0.373, p=0.154) and T_3m (r=-0.302, p=0.204).

Conclusion: TF⁺EMP may not contribute to hemostatic abnormalities in HNC patients.

Keywords: Endothelial microparticles; coagulation activation; head and neck cancer; thrombin-antithrombin complex; tissue factor.