Introduction
Thrombocytes are components of the blood, also known as platelets. They perform an important task in blood clotting by being responsible for closing the vessels in case of injury. The number of thrombocytes can be determined from a small blood count and can occasionally be reduced.
If the number of thrombocytes in the blood has fallen below the normal value, this is called thrombocytopenia or thrombocytopenia. The causes can be very different. On the one hand, the lack of thrombocytes in the blood can be caused by the fact that not enough new thrombocytes are produced by the body or the existing thrombocytes are increasingly broken down. If the number of thrombocytes is only slightly lower than the normal value, it can usually be tolerated and compensated for well by the human body as long as no other diseases are present. However, if the number of thrombocytes has fallen far below the normal value, this can lead to heavy bleeding even in the case of minor injuries.
The causes
A reduced number of thrombocytes in the blood can have many different causes. Usually, the deficiency is due to a disturbed formation of new platelets or an increased breakdown of these. A reduced platelet count can be caused by a congenital disorder, for example, and is usually diagnosed at a young age.
However, the educational disorders can also develop in the course of life. The reason for this can be a bone marrow disease, such as leukemia, or bone marrow damage caused by drugs, toxic substances, radiation or tumors. A deficiency of vitamin B12 or folic acid can also be responsible for the number of thrombocytes in the blood falling, as these important nutrients are no longer available for the formation of thrombocytes in the event of a deficiency.
If an increased breakdown is responsible for the deficiency of platelets, the cause can be, for example, an activation of the coagulation or a reaction with antibodies. Mechanical damage to the thrombocytes by artificial heart valves, for example, can also be a cause of increased platelet degradation. Pseudothrombocytopenia occurs when the platelets are falsely measured too low in the laboratory sample but are present in normal numbers in the patient.
Chemotherapy is a treatment with so-called cytostatic drugs (= cell killing agents). These cytostatic drugs are chemical substances which are intended to kill the diseased cells in particular. Physical irradiation, so-called radiotherapy or hormone therapy is also intended to kill off diseased cells.
All these treatments can unfortunately also induce the death of healthy cells as a side effect. This can also affect blood components such as thrombocytes. Since the thrombocytes are responsible for blood clotting, a drop in the platelets can mean that even the smallest injury can lead to a large bleed.
Therefore, the number of platelets is measured and controlled at regular intervals during chemotherapy. The abbreviation HIT stands for heparin-induced thrombocytopenia. If patients take the drug heparin, various reactions in the body can lead to a drop in the number of thrombocytes.
One speaks of a HIT if the number of thrombocytes has dropped to less than 50% of the initial value before starting therapy with the drug. There are two types of HIT, HIT type 1 and HIT type 2. HIT type 1 is usually the relatively harmless form of HIT, as the platelets only react directly with the drug heparin.
The clinically less favorable form is HIT type 2, in which antibodies are formed in the body, causing platelets to clump together. This agglutination can lead to thrombosis, for example. Since there is always a risk of HIT in patients with heparin, a starting value of the thrombocytes should be determined before starting therapy and then checked at regular intervals.
Werlhof’s disease, also known as Werlhof’s disease, is an autoimmune disease in which antibodies of the human body are directed against the patient’s own thrombocytes. If the antibodies formed bind to the body’s own platelets, they are broken down in the spleen.This leads to a deficiency of thrombocytes in the blood. The thrombocytes can no longer perform their task of clotting the blood so well and a tendency to bleed can occur.
The cause of Werlhof’s disease is still unknown. Symptoms are often observed in patients after a viral infection of the upper respiratory tract, which is why this is being discussed as a possible cause. The severity of the disease can vary greatly and sometimes it can be completely without clinical symptoms.
