Alternatively spliced tissue factor: a previously unknown piece in the puzzle of hemostasis.

Alternatively spliced tissue factor (asTF) has recently been discovered as a soluble form of tissue factor (TF), which circulates in blood and exhibits procoagulant activity. This soluble TF variant expanded the concept of circulating TF by a further element. Up to 30% of the TF antigen found in circulating blood was proposed to be derived from alternative splicing. We showed that cytokines induced the expression of asTF and the release from endothelial cells. The use of plasma asTF as a clinical marker for an inflammation-associated dysregulated hemostasis may therefore be a novel approach in predicting the patients' prognosis. This review covers the latest findings in the field of soluble TF focusing on asTF and its potential role besides the one in coagulation.