GAS6 in systemic inflammatory diseases: with and without infection

Vitamin K-dependent proteins are not only essential regulators of blood coagulation. A recent paper in Critical Care describes the levels of the vitamin K-dependent GAS6 and the soluble form of its receptor Axl, in plasma from patients with sepsis of systemic inflammation. The results confirm that GAS6 is elevated during septicemia, but the fact that inflammatory conditions without infection produce a similar effect suggest that it is inflammation what induces the synthesis of GAS6, rather than the interactions with bacteria or other infectious agents. The soluble form of the GAS6 receptor, sAxl, was induced less compared to the effect observed in GAS6. This is important, as the two proteins form an inactive complex in plasma and suggests that a functional GAS6 form could be synthesized in these conditions. GAS6 has been proposed as a broad regulator of the innate immune response. Therefore, its synthesis is likely to be a regulatory mechanism during systemic inflammation. Recent advances provide necessary the tools for further research, including genetic screenings of the components of this system.