Activation of circulated immune cells and inflammatory immune adherence are involved in the whole process of acute venous thrombosis.

Objective: To investigate localization and distribution of integrin subunit β1, β2 and β3 and morphological changes of ligand-recepter binding in thrombi of acute pulmonary embolism (PE) patients and explore activation of circulated immune cells, inflammatory immune adherence and coagulation response in acute venous thrombosis.

Methods: Thrombi were collected from patients with acute PE. Immunohistochemistry was done to detect the expression and distribution of integrin β1, β2 and β3 in cells within thrombi, and ligands of integrin subunit β1, β2 and β3 were also determined by immunohistochemistry within the thrombi.

Results: 1) Acute venous thrombi were red thrombi composed of skeletons and filamentous mesh containing large amounts of red blood cells and white blood cells; 2) Integrin subunit β1, β2 and β3 were expressed on lymphocytes, neutrophils and platelets; 3) No expression of integrin β1 ligands: Laminin, Fibronectin, Collagen I or Collagen-II on lymphocytes; integrin β2 ligands including ICAM, factor X and iC3b are distributed on neutrophils, and ligand fibrinogen bound to neutrophils; integrin β3 was expressed on platelets which form the skeleton of thrombi and bound to fibrinogen to construct mesh structure; 4) Factor Xa was expressed on the filamentous mesh; 5) Filamentous mesh was fully filled with red blood cell dominant blood cells.

Conclusion: Acute venous thrombosis is an activation process of circulated lymphocytes, neutrophils and platelets mainly, and a whole process including integrin subunit β2 and β3 binding with their ligands. Activation of immune cells, inflammatory immune adherence and coagulation response are involved in the acute venous thrombosis.