Immune thrombocytopenia (ITP)
What is immune thrombocytopenia purpura?
Definition
Immune thrombocytopenia (ITP), also known as immune thrombocytopenic purpura, is a rare disease in which the patient's immune system attacks and destroys platelets. Platelets are cell fragments responsible for blood clotting. The decrease in the amount of platelets in the blood can cause bleeding, as clotting becomes insufficient.
Symptoms of immune thrombocytopenia
The coagulation defect caused by ITP can lead to various types of hemorrhage:
- Cutaneous symptoms: subcutaneous bleeding can cause red spots to appear under the skin. This phenomenon is called "purpura". If the spots are small and numerous, they are called petechiae. In addition, ITP patients are more likely to develop bruises and ecchymosis following a low-impact trauma.
- Bleeding: superficial bleeding may occur, especially from gums or nose. Patients may sometimes find blood in their urine or stool, and patients' menstrual flow may be particularly heavy. In addition, small wounds that are normally benign may trigger excessive bleeding.
- Internal hemorrhage: immune thrombocytopenic purpura can also cause internal bleeding, such as gastrointestinal bleeding. A rare complication is brain hemorrhage, which can be particularly serious.
Causes and risk factors of immune thrombocytopenia
ITP is provoked by an autoimmune reaction, in which the patient's antibodies attack and destroy his or her platelets. This condition is more common in young women, and in patients with other autoimmune diseases, such as rheumatoid arthritis or lupus. Sometimes the disease is triggered by an infection, such as HIV, H. Pylori, or by certain types of hepatitis. In children, ITP often follows a viral infection, such as mumps or influenza, and is self-limited.
Diagnosing immune thrombocytopenia
The diagnosis is made upon observation of an abnormally low platelet count, in the absence of other blood work abnormalities, and after exclusion of other possible causes such as ongoing drug therapy or underlying pathology. In some cases, bone marrow examination may be necessary to confirm the diagnosis.
Treating immune thrombocytopenia
In patients with adequate platelet levels, and in the absence of bleeding, management may consist of simple medical follow-up. When platelet count is low or when blood loss is detected, different treatments can be recommended.
The first line of treatment consists most often of oral steroids, such as prednisone. Their immunosuppressive action limits the destruction of platelets, but these medications must be gradually discontinued once a sufficient platelet count has been reached, because of their potential long-term side effects.
If steroids are not effective, or if bleeding is severe, the physician may prescribe immunoglobulin injections, which act quickly and are effective in limiting platelet destruction.
Rituximab (Rituxan, Truxima), can also be used to inhibit the immune response which targets the platelets.
In addition, there are treatments that can boost platelet production. Romiplostim (Nplate) and Eltrombopag (Promacta) stimulate platelet production by the bone marrow, but they carry the risk of blood clots.
Finally, surgical treatment can be part of the care plan for patients with ITP. Surgery consists of removing the spleen, or splenectomy. The spleen is the main site of platelet destruction and autoantibody production. However, this option is not suitable for all patients, and it has the disadvantage of increasing patients’ vulnerability to infection.
Living with immune thrombocytopenia
It is recommended that patients avoid contact sports to limit the risk of trauma that can cause bleeding. The use of soft-bristled toothbrushes can limit bleeding from the gums. Some over-the-counter medications (aspirin, non-steroidal anti-inflammatory drugs, etc.) are not recommended for ITP patients because they interfere with platelet functioning. Finally, patients who have had a splenectomy should be particularly vigilant for signs of infection, such as fever, and must be taken care of promptly if they develop the symptoms.
