Symptoms

Patients usually stand out due to the early occurrence of venous blood clots between the ages of 15 and 45. Especially women suffer unexpectedly and without prior knowledge of their disease, a thrombosis (vascular occlusion by a blood clot), more often in the deep veins of the legs. This usually occurs in high-risk situations, including during the intake of estrogens (birth control pill, hormone preparations against menopausal symptoms) or pregnancy, as these are also associated with a decrease in protein S concentration.

Other risk factors for deep vein thrombosis that affect both sexes equally are

Operations,
Longer immobilization/immobilization of the legs after an operation or during a longer flight/bus journey,
As well as increased fluid loss.

The disease can only be detected by analyzing the patient’s blood. If a patient is suspected of having an increased tendency to clotting, a venous blood sample is usually taken and then the activity of the anticoagulant factors in the blood, such as Protein S, is analyzed in the laboratory. It should be noted, among other things, that Protein S and the other factors only have a short half-life, i.e. their activity can only be detected within a relatively short time window, so it is important to avoid long transport routes to a laboratory.

It is therefore recommended to have these tests performed by a specialist with an affiliated laboratory or in a hospital. Furthermore, the synthesis of protein S and protein C is also vitamin K-dependent, so that an existing medication with vitamin K antagonists (opponents), such as Marcumar, can lead to false low values. It should also be noted that the concentration of Protein S in women is generally about twenty percent lower than in men of the same age and can be additionally lowered in connection with increased estrogen levels (for example, when taking the contraceptive pill or hormone preparations during menopause), as well as during and shortly after pregnancy. Therefore, a minimum interval of eight weeks after the last intake of the vitamin K antagonist is recommended, as well as the end of the influence of estrogen.