From the Guidelines
Abnormal levels of tissue factor can occur due to various pathological conditions, with cancer being a significant contributor, as tumor cells often produce excessive tissue factor, leading to a hypercoagulable state and increased risk of thrombosis, as supported by the most recent study 1.
Pathological Conditions Contributing to Abnormal Tissue Factor Levels
Abnormal levels of tissue factor can be caused by several factors, including:
- Inflammatory conditions like sepsis, atherosclerosis, or cancer, where inflammation activates cells to express more tissue factor
- Autoimmune disorders like antiphospholipid syndrome, which can increase tissue factor expression
- Vascular injuries, such as those occurring during surgery or trauma, which expose tissue factor to blood, triggering coagulation
- Certain medications, including hormonal therapies like estrogen-containing contraceptives, which can upregulate tissue factor
Cancer and Tissue Factor
In cancer specifically, tumor cells often produce excessive tissue factor, contributing to the hypercoagulable state and increased risk of thrombosis seen in cancer patients, as shown in studies 1. The release of tissue factor by tumor cells can directly activate the coagulation cascade, leading to thrombosis. Additionally, tissue factor can stimulate angiogenesis, which is critical to the growth of solid tumors.
Clinical Significance
These abnormalities in tissue factor levels are clinically significant because they can lead to either excessive clotting (thrombosis) or inadequate clotting (bleeding), depending on whether levels are increased or decreased. The most recent study 1 highlights the importance of considering tissue factor levels in cancer patients, as high levels of tissue factor expression have been shown to predict poor prognosis in patients with ovarian and pancreatic cancers.
From the Research
Abnormal Levels of Tissue Factor
Abnormal levels of tissue factor can be caused by various factors, including:
- Pathological conditions such as septic shock, atherosclerosis, and cancer, which can lead to aberrant expression of tissue factor by endothelial cells, monocytes, or macrophages 2
- Trauma, which can cause the release of constitutively expressed tissue factor into the circulation and induce tissue factor expression on monocytes and other cells 3
- Cellular necrosis, which can result in the release of endogenous cell surface-bound tissue factor 4
- Inflammation, which can lead to increased levels of tissue factor 4
Conditions Associated with Abnormal Tissue Factor Levels
Abnormal levels of tissue factor have been associated with various conditions, including:
- Cancer, where tissue factor is produced by tumor-associated macrophages and plays a role in tumor growth and dissemination 2
- Sepsis, where inducible tissue factor expression on monocytes leads to disseminated intravascular coagulation 5
- Atherosclerosis, where tissue factor is expressed on macrophage foam cells and microvesicles, driving thrombus formation after plaque rupture 5
- Trauma, where tissue factor plays a role in organ dysfunction and multiple organ dysfunction syndrome 3
Measurement of Tissue Factor Levels
Tissue factor levels can be measured in various biological fluids, including:
- Plasma, where normal levels of tissue factor antigen are around 165 +/- 139 pg/ml 4
- Serum, where normal levels of tissue factor antigen are around 165 +/- 110 pg/ml 4
- Other fluids, such as cerebrospinal fluid, peritoneal fluid, pleural effusion, and urine, where tissue factor levels can vary depending on the condition 4