Thrombocytopenia (low platelet count) is a reduced number of platelets in your blood. Thrombocytopenia is defined when the peripheral blood platelet count is <150,000 / µl.Symptoms of thrombocytopenia are cutaneous and mucosal bleeding: small ecchymoses (bruises) appear in the skin of the limbs, trunk, and less often the face and oral mucosa. Bleeding from the gums, nose, urinary tract, and genital tract in women is common.

What is thrombocytopenia?

Hemostasis-blood coagulation processes

By hemostasis we understand all the processes in the body that help blood to clot properly. These phenomena include both the correct formation of clots, for example in the event of an injury, and the conditions that ensure the fluidity of the blood in the blood vessels. It is therefore a system of processes which, depending on the circumstances, can either increase the thickness of the blood (until it clots) or decrease the thickness of the blood (preserve its fluidity). Only the perfect balance between these phenomena determines the proper behavior of blood in the circulatory system.

The factors determining the maintenance of this balance are: the appropriate number and function of platelets, the presence and activity of appropriate clotting factors in the blood, as well as the correct structure and function of the vessels (veins, arteries, capillaries) in which the blood flows.

Platelets

Platelets (thrombocytes) are one of the basic cellular components of blood. Like other blood cells, they are made in the bone marrow, the liquid tissue that is contained within some bones (e.g., sternum, hip bones). The process of their formation is based on the systematic detachment of flaky fragments (or plates) from the “mother cell” called the megakaryocyte. Thrombocytes are not proper cells because they do not contain all the characteristic cellular elements within them.

Thrombocytopenia is a disorder in which the number of platelets in the blood is abnormally low. Thrombocytopenia is defined when the peripheral blood platelet count is <150,000 / µl. However, these values ​​are present in approximately 2.5% of the healthy population, so if the platelet count is stable in the range of 100,000–150,000 / µL for at least 6 months, it is probably a variant of the norm.

Frequency of appearance

Note that approximately 2.5% of the population can have a platelet count of less than 150,000 / µl, and this is not a disease. Thrombocytopenia can also be found in approximately 5% of pregnant women.

The most common type of thrombocytopenia isimmune thrombocytopenia, which occurs at a frequency of 3–3.5 / 100,000 people per year in adults. The mean age of onset is in the 5th decade of life. Among patients aged 30–60 years, there are more women, and those aged> 60 years, the incidence of the disease is similar in both sexes.

Thrombocytopenia – causes

The causes of thrombocytopenia can be different. Thrombocytopenia is most often caused by a decrease in the production of platelets in the bone marrow, their excessive destruction in the blood (due to the action of immune or non-immune factors) or disturbed consumption in the body.

It can be caused by an insufficient production of platelets in the bone marrow. It is a congenital (rarely, usually manifested in childhood) or acquired condition.Reasons for an acquiredreduction in platelet production include:

• marrow aplasia(acquired aplastic anemia, nocturnal paroxysmal hemoglobinuria, acquired selective megakaryocytic aplasia),
• cyclic thrombocytopenia(a decrease in the number of platelets in the blood regularly every 21-39 days, most often in young women),
• deficiency thrombocytopenia(vitamin B₁₂orfolatedeficiency ,iron deficiency anemia[rare],copperdeficiency ),
• bone marrowinvasion byneoplasmsof the haematopoietic and lymphatic systems, neoplastic metastases, Gaucher’s disease,tuberculosis, bone marrow fibrosis,haemophagocytic syndrome,
• bone marrow damageby physical and chemical factors (ionizing radiation, myelosuppressants [damaging the bone marrow], thiazide diuretics,estrogens, alcoholism and ethyl alcohol intoxication, viral infections).

Thrombocytopenia can also result from the excessively rapid clearance of platelets from the circulation, e.g. due to the action of antibodies. This is calledimmune thrombocytopenia. It occurs when the body is unable to correctly recognize platelets as part of the body and treats them as “foreign” cells, trying to neutralize them. It can also interfere with the proper production of thrombocytes in the bone marrow. Such a condition occurs, inter alia, in as a rare complication of blood or blood products transfusion, in the course of certain infections, in the course of autoimmune diseases, in some pregnant women, in patients after bone marrow transplantation, and in the course of therapy with certain drugs, mainly heparin, and non-steroidal anti-inflammatory drugs, some antibiotics, gold salts and a number of other drugs, as well as the SARS-CoV-2 vaccine.

Non- immune causesof excessive platelet removal from the bloodstream include: disseminated intravascular coagulation syndrome (DIC) and hemolytic uremic syndrome (HUS). Another cause of thrombocytopenia may be the increased uptake and destruction of platelets by a malfunctioning spleen, or so-called hypersplenism.

Sometimes the so-calledpseudo- thrombocytopenia, arising from abnormal clumping of platelets in a tube to which blood has been collected. In this case, the platelet count may be falsely low despite the fact that the platelet count is normal in your blood. To obtain the correct result, blood should be taken into a test tube containing a special chemical reagent – sodium citrate or heparin.

Thrombocytopenia – symptoms

In people with thrombocytopenia, symptoms of ableeding disorderdo not usually become apparent until the platelet count is below 30,000 / µl. The symptoms may be different for each patient, most often there is no simple relationship between the number of platelets and the severity of symptoms.

In patients with thrombocytopenia, the symptoms may be chronic or paroxysmal.The most typicalof thrombocytopenia are:

• bleeding from the skin or mucous membranes, such as nosebleeds
• prolonged, heavy menstruation,
• bleeding gums after tooth extraction,
• increased tendency to the occurrence of bruises,
• petechiae (small, punctual, vivid red lesions on the skin).

Bleeding from the gums, urinary tract or genital tract in women may occur frequently. Rare but serious complications include gastrointestinal bleeding (vomiting blood discolored or vomiting with dark, gritty contents, a change in color to very dark, “tarry” stools) or intracranial bleeding (sudden neurological disturbances such asdizziness, numbness in the body or limbs) paresis of limbs or face, speech disorders).

What to do in case of symptoms of thrombocytopenia?

If you experience symptoms that may indicate thrombocytopenia, see your GP who will schedule basic blood tests. If abnormalities suggesting a platelet disorder are detected, further in-hospital diagnosis will be required in the hematology clinic or in the appropriate hospital ward for the final diagnosis and initiation of treatment.

If a patient suffering from one of the platelet bleeding disorders notices worsening of symptoms, he should immediately contact his treating physician and perform ablood countcheck to determine the current platelet count.

Diagnosis of too few platelets

The diagnosis of thrombocytopenia is made on the basis of a reduced number of platelets in the blood count. As part of further diagnosis, extended blood tests are performed to identify the causes of thrombocytopenia and detect possible complications. In most cases, a bone marrow examination is necessary, such as a puncture or a bone marrow biopsy. With the help of this test, you can accurately assess what the blood production looks like: are cells responsible for the production of platelets (megakaryocytes) present, and whether their appearance and function are normal. It can also tell if there are any abnormalities that can stop the production of platelets in the blood. The diagnosis of the disease is based on a comprehensive assessment of the patient’s clinical symptoms, abnormal thrombocyte counts seen in the blood count, possible abnormalities in the examination of the bone marrow and trepanobiopsy. Additional circumstances such as pregnancy, ongoing infection or the use of drugs that may interfere with the proper production and function of platelets are also considered separately.

Treatment of thrombocytopenia

Treatment of thrombocytopenia depends on its cause, as it is often the result of other diseases, conditions, or medications. Depending on the diagnosis, treatment can be started immediately or in the event of clinical symptoms. The goal of treatment is not to restore your blood platelet count to normal, but to protect the patient from major bleeding. It is estimated that the platelet count is approximately 30-50,000 / µl for a smooth clotting system. Higher values ​​will be required prior to surgery.

The treatment procedure includes:

• exclusion of drugs that can cause thrombocytopenia;
• in the presence of severe thrombocytopenia, it may be necessary to transfuse a concentrated platelet cell;
• use of drugs from the group of glucocorticosteroids, which may result in a gradual increase in the number of platelets to the levels ensuring the proper functioning of the coagulation system;
• the use of an intravenous immunoglobulin preparation (abbreviated as IVIG);
• antibiotic therapy to treat infections that may result in thrombocytopenia (including elimination of Helicobacter pylori infection);
• the use of immunosuppressants as a next-line treatment in the event of failure of glucocorticoid therapy;
• removal of the spleen (splenectomy) may be indicated in some patients;
• bone marrow transplantation is sometimes used to treat congenital thrombocytopenia.

Thrombocytopenia is often a chronic disease that cannot be cured, and therapy is aimed at reducing the symptoms of the disease and preventing complications. Bone marrow transplantation is sometimes used as an effective treatment for severely genetically determined diseases. When drug-induced platelet disorders are taken, treatment may be considered if you stop taking them. Likewise, thrombocytopenia in pregnant women, which usually resolves after childbirth, is similar.

In general, regular blood counts to assess platelet counts are indicated. The attending hematologist determines the frequency of follow-up visits.

What to do to avoid developing thrombocytopenia?

It is advisable to avoid the drugs mentioned above, and if it is impossible to reduce their use, blood counts should be monitored regularly. It is also advisable to limit alcohol consumption.