Symptoms
The symptoms of protein C deficiency depend strongly on the activity of the protein and its concentration in the blood. The severity of the symptoms is closely related to the measured values. Slightly lowered values are only clinically noticeable in rare cases.
In the severe form, both congenital and acquired, various symptoms come to the fore, which are caused by microthromboses in the smallest blood vessels in the skin and organs. Initially, there are small, punctiform bleedings on the skin, which cannot be pushed away under pressure (petechiae). In the further course of the disease, these bleedings become flat and flow into each other.
In technical terms, this appearance is called Purpura fulminans.As the capillaries that supply the skin with oxygen become increasingly clogged with tiny blood clots, skin areas continue to die off (skin necrosis), causing pain. These microthrombi also occur in all organs and thus cause the severe course that a protein C deficiency can take, which can lead to multiorgan supply, amputations of body parts and, if left untreated, even death. Congenital protein C deficiency in newborns is associated with increased incidence of venous thrombosis, i.e. blood clots in larger veins.
Children have a higher risk of so-called atypical thromboses in the brain or intestine. The diagnosis of protein C deficiency is not so much a clinical one as a laboratory one. After a normal blood sample is taken, the blood can be tested for concentration of protein C and its activity.
First, the activity of the protein is measured in %, with the normal range for adults being between 70 and 140%, measured against the average activity in healthy individuals. From 20-25% on, severe symptoms occur that require treatment. In a further step, the number of protein C in the blood can be determined.
This only makes sense if a reduced activity has been noticed beforehand or if the patient suffers from symptoms that are compatible with a protein C deficiency. Here the normal range is 2-6 mg/l for adults. A protein C deficiency is diagnosed when the activity drops below 70%, whereupon a differentiation into type 1 (reduced) and type 2 (normal) is made on the basis of the blood concentration. In order to exclude and clarify acquired and reversible causes, the status of the liver and any medication taken should be clarified. A vitamin K determination can also be useful.
