Monocytes express tissue factor in young patients with cerebral ischemia

Area of Science:

• * Neuroscience
• * Hematology
• * Immunology

Background:

• * Blood coagulation and fibrinolysis are activated in stroke patients.
• * The specific factors accelerating coagulation, especially without predisposing conditions, remain unclear.
• * Monocytes expressing tissue factor (TF) are hypothesized to initiate thrombosis.

Purpose of the Study:

• * To investigate the role of monocyte-expressed tissue factor (TF) in stroke.
• * To determine if TF expression on monocytes contributes to accelerated coagulation in stroke patients.
• * To correlate TF expression with coagulation activation markers and clinical phases of stroke.

Main Methods:

• * Quantification of TF antigen on monocytes using flow cytometry and indirect immunofluorescence in 48 stroke patients and 40 controls.
• * Assessment of TF functional activity via a one-stage clotting assay.
• * Measurement of coagulation activation markers: thrombin-antithrombin complex, F1 + 2 fragments, and D-dimer levels.

Main Results:

• * Significantly increased TF antigen expression on monocytes in both acute and chronic phases of stroke (p < 0.01 and p < 0.05, respectively).
• * TF antigen demonstrated functional pro-coagulant activity.
• * Elevated thrombin-antithrombin complex and F1 + 2 fragments in both phases; D-dimer elevated only in the chronic phase.

Conclusions:

• * TF expression on monocytes is elevated in cerebral ischemia patients.
• * This enhanced TF expression suggests a significant role in activating blood coagulation.
• * Monocyte-derived TF contributes to the observed hypercoagulable state and subsequent fibrinolysis in stroke.