Idiopathic thrombocytopenic purpura
Idiopathic thrombocytopenic purpura (ITP) is a blood disorder characterized by a low platelet count due to the immune system mistakenly attacking its own platelets. This condition can lead to difficulty stopping bleeding, as platelets play a crucial role in blood clotting. ITP is categorized into two types: acute, which typically affects children and lasts less than six months, and chronic, which is more common in adults and lasts longer than six months. While the exact cause of ITP is often unknown, it may be linked to viral infections in children and can be associated with other factors in adults, such as certain medications or immune disorders.
Symptoms of ITP can include easy bruising, prolonged bleeding from injuries, and the presence of red or purple spots on the skin. Diagnosis usually involves a medical history review, physical examination, and blood tests to assess platelet levels. Treatments vary based on the severity of the disorder and can include medications to boost platelet production or, in some cases, splenectomy, which involves removing the spleen to reduce platelet destruction. Although there is no known prevention for ITP, individuals are advised to avoid activities that increase the risk of injury and to maintain a healthy lifestyle. Most children with ITP recover spontaneously, while adults may require ongoing management.
Idiopathic thrombocytopenic purpura
- ANATOMY OR SYSTEM AFFECTED: Blood, immune system, spleen
- ALSO KNOWN AS: Immune thrombocytopenic purpura
Definition
Idiopathic thrombocytopenic purpura (ITP) is a treatable blood disorder. Antibodies that are produced in the spleen attack and destroy the body’s own blood-clotting cells (platelets), which help stop bleeding. Normally, platelets move to damaged areas of the body and stick together, forming a sort of barrier against germs. If there are not enough platelets in the body, bleeding injuries are difficult to stop. Although people with ITP have a lower than normal number of platelets in their blood, all other blood cell counts are normal.
There are two types of ITP. Acute ITP, which lasts less than six months and usually occurs in children, is the most common. Chronic ITP lasts more than six months and usually occurs in adults.
Causes
The cause of most cases of ITP is unknown. In children, the disorder has been linked to viral infections. It is believed that in these cases, the immune system becomes confused and begins attacking healthy platelet cells. When too many platelets are destroyed, ITP can result. The disorder in adults has not been linked to viral infections. Some cases of ITP are thought to be caused by drugs, infection, or other immune disorders, including HIV, hepatitis C, varicella zoster, or cytomegalovirus. Pregnant women sometimes develop the disorder.
Risk Factors
Persons with an increased chance of developing ITP include children who have had a recent viral infection or have had a live-virus vaccination (which may sometimes put a child at higher risk); women, usually younger than age forty; and women in general, who are two to three times more likely to get ITP than are men. Individuals who have rheumatoid arthritis, lupus, Addison's disease, low-grade lymphomas, or leukemias are at an increased risk of developing ITP.
Symptoms
Both adults and children may notice the following symptoms of ITP: easy bruising (often on the shins), dark urine or stools, bleeding for longer than normal following an injury, unexplained nosebleeds that are difficult to stop, bleeding from the gums, heavier-than-normal or longer menstrual periods (in adult women), red or purple dots called petechiae on the skin (petechiae may occur in groups and resemble a rash), and, in rare cases, bleeding within the intestinal tract or brain.
Screening and Diagnosis
A doctor will ask about symptoms and medical history and will perform a physical exam. Tests may include a complete blood count (CBC), in which a blood sample is tested to see if the numbers of different blood cells are normal; and a bone marrow test, in which a needle is inserted into the skin and into the bone and a small amount of bone marrow is removed. The sample is tested to ensure the marrow contains normal numbers of platelet-producing cells. This test is done to rule out other disorders. Another test is a computed tomography (CT) scan (in rare cases). The CT scan is done if there is a concern about bleeding in the brain.
Treatment and Therapy
Treatment for ITP is different for children and adults and varies based on the severity of the condition. Most children recover from ITP without any treatment. However, a doctor may recommend the following: medications to increase platelet counts in the blood, such as corticosteroids (for example, prednisone), which lowers the activity of the immune system and keeps it from destroying platelets; and gamma globulin infusions (an antibody-containing protein that slows down platelet destruction). An infusion means that the injection is given by IV (intravenously) or through a shot. It usually works more quickly than steroids. Both of these treatments work but both can have side effects. Eighty-six percent of children who have ITP recover within a year and do not experience the problem again.
Three drugs developed in the twenty-first century stimulate platelet production: eltrombopag (Promacta), romiplostim (Nplate), and avatrombopag (Doptelet). Fostamatinib (Tavalisse) may be helpful for individuals who fail to respond positively to other treatments. Using these drugs and also using the targeted monoclonal antibody rituximab (Rituxan, Ruxience, Truxima) may prevent the need for a splenectomy. A splenectomy is the surgical removal of the spleen. This procedure stops the destruction of platelets because the antibodies are made in the spleen. In adults, if drug intervention does not do enough to raise platelet counts, the doctor may recommend a splenectomy.
A splenectomy leaves the body more vulnerable to infection from other sources. This surgery is usually not performed until medications have proven ineffective. Doctors also sometimes recommend lifestyle changes when platelet counts are low, including avoiding contact sports; patients also are recommended to wear a helmet during sports activities.
Prevention and Outcomes
Because the cause of ITP is unknown, there are no specific ways to prevent the disease. However, because bleeding and injury can be serious for people with ITP, one should take precautions to avoid injury, such as using padding on an infant’s crib or around a play area and ensuring that older children wear helmets and protective gear when playing sports (to help reduce bruising injuries). Persons with low platelet counts should stop playing contact sports.
People who have ITP should also avoid medications that contain aspirin or ibuprofen. These medicines can reduce platelet function. To help stay healthy, one should eat a healthful diet, low in saturated fat and rich in whole grains, fruits, and vegetables; get regular exercise; lose weight if overweight; stop smoking; and drink alcohol, if desired, only in moderation (two drinks per day for men and one drink per day for women).
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