Effect of Blood Coagulation on Immunological Reactivity of Blood Cells <i>Ex Vivo</i>

BACKGROUND: The interaction between hemostasis and the immune system provides the body’s defense against external pathogens. However, the impact of blood coagulation on immune cell reactivity is poorly understood. AIM: To investigate the effect of blood coagulation on its immunoreactive properties ex vivo. METHODS: Donor blood samples were incubated with heparin (for plasma studies) or without heparin (for serum studies). Plasma and serum antioxidant activity was evaluated by chemiluminescence intensity after addition of hydrogen peroxide or ozonated physiological solution. Cytokine content was determined by enzyme-linked immunosorbent assay after incubation of blood with lipopolysaccharide (LPS) for 3 or 18 h. RESULTS: Serum had a significantly greater antioxidant activity compared to plasma. The blood coagulation process markedly reduced both spontaneous and LPS-induced secretion of tumor necrosis factor TNF-α by blood cells, without significantly affecting the secretion of interleukins IL-1, IL-6, IL-8 and CRP. However, this process led to an increase in both spontaneous and LPS-induced secretion of vascular endothelial growth factor (VEGF) by blood cells. Serum samples with LPS also showed a marked increase in procalcitonin. CONCLUSION: Blood coagulation enhances the antioxidant properties of blood, reduces the inflammatory activity of immunoreactive cells, thereby promoting regenerative processes.