Part I　Venous thrombus

Immune cell balancing function collapse refers to no function or significant dysfunction of immune cells, involving mostly T lymphocytes. Under the condition of immune cell balancing function collapse, acute venous thrombosis originates from intravenous immune adhesive inflammatory reactions triggered by infected cells/malignant tumor cells, which happens throughout the whole process of genesis of venous thrombosis.

Thrombotic inflammation, including infectious inflammation (by pathogenic microorganism) and non-infectious inflammation (by malignant tumor cells), is a defensive response. The outcome of inflammation depends on the strength of immune cell balancing function. With the condition of immune cell balancing function collapse, the human body loses the function of eliminating intravenous infected cells/malignant tumor cells timely and effectively. Thus, integrin subunits β1, β2 and β3 on the membrane of platelets and white blood cells are activated to combine with the ligand fibrinogen into a reversible mesh-like structure, which is like the intravenous biological filter and acts as physical defense of the human body to prevent the infected cells/malignant tumor cells in the distal veins from flowing back. During the process of defense, blood cells, mainly red blood cells, stagnate and fulfill the filter, which stops the blood flow in the local veins and thus results in venous thrombotic diseases.

The process, in which integrin β2 and β3 receptors on white blood cells or platelets membrane combine with their ligands fibrinogen, is reversible and easy to be disintegrated. Thus, only under the condition of stasis can the biological filter form.Otherwise, the combinations will be impacted into pieces by the quick blood flow.Integrin β2 on the membrane of neutrophils combines with its ligand Factor X to Factor Xa, activates coagulation factors and converts fibrinogen in the filamentous sieve into fibrin, which makes the intravenous biological filter firm. Fibrinoid inflammation is the pathological manifestation of venous thrombosis.

In people with a sound immune function, infected cells/malignant tumor cells can be removed timely and ef f ectively, which makes it unnecessary to start the intravenous biological filter to act as a compensatory physical defense. Thus, acute venous thrombotic events will not take place under such circumstances. Patients with collapsed immune cell balancing functions are a group of people,who have particularly high risks of venous thrombosis. Meanwhile, anyone who has venous thromboembolism may have infected cells/malignant tumor cells in veins, which may trigger the genesis of venous thrombosis. Only under the condition of immune cell balancing function collapse, the risk factors, such as advanced age, infection, trauma, surgery, autoimmune disease, longtime bedding, pregnancy, delivery as well as long trip syndrome, may cause venous thrombosis. However, even with definable risk factors, venous thromboembolism usually does not form in people with sound immune functions.

(Published: Int J Clin Exp Med 2015;8(11):19804-19814)