New Treatments Show Promise in Immune Thrombocytopenia
Emerging therapies improve platelet counts in immune thrombocytopenia.
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Immune Thrombocytopenia (ITP)
Also known as: Idiopathic thrombocytopenic purpura, Primary immune thrombocytopenia, Autoimmune thrombocytopenia
Primary organ/tissue: Blood and immune system (affects platelets in the bloodstream)
Overview
Immune thrombocytopenia (ITP) is an autoimmune disorder where the immune system mistakenly attacks and destroys platelets, which are blood cells that help with clotting. This leads to an abnormally low platelet count, increasing the risk of bruising and bleeding - even from minor injuries. ITP can be acute (short-term) or chronic (lasting more than 6 months) and may occur on its own or alongside other autoimmune diseases.
Symptoms
Easy bruising; Petechiae - tiny red or purple spots on the skin; Frequent nosebleeds; Bleeding gums; Heavy menstrual periods; Prolonged bleeding from cuts; Blood in urine or stool; Fatigue. In rare, severe cases, internal bleeding or brain hemorrhage can occur. Some people have no symptoms.
Causes
The immune system produces autoantibodies that attack platelets. Sometimes targets the cells in the bone marrow that produce platelets. Possible triggers: Viral infections (especially in children, e.g., Epstein-Barr, hepatitis, HIV, or after COVID-19), Vaccinations (rarely), Autoimmune diseases (like lupus or antiphospholipid syndrome), Certain medications, Pregnancy, Cancers like lymphomas (rarely).
Diagnosis
No single test for ITP - it is a diagnosis of exclusion. Tests include: Complete blood count (CBC) - shows low platelets with otherwise normal blood cells; Blood smear to rule out other blood disorders; Bone marrow biopsy (in rare cases, especially in older adults); Tests for infections or autoimmune markers.
Treatment
Observation only for mild cases with no bleeding; Corticosteroids (prednisone) - first-line treatment; IVIG for rapid platelet boost, especially in emergencies; Rituximab - a biologic that targets immune B cells; Thrombopoietin receptor agonists like eltrombopag or romiplostim; Splenectomy - removal of the spleen, considered in chronic, treatment-resistant cases.
Prognosis
In children, most cases resolve within weeks to months. In adults, ITP is often chronic but manageable. Severe complications (like brain bleeding) are rare, especially with proper treatment.
Prevalence
Affects 3-4 per 100,000 adults per year. More common in women under 60. Higher risk in those with other autoimmune diseases.
Autoantibodies
| Autoantibody | Notes |
|---|---|
| Anti-platelet antibodies (directed at GPIIb/IIIa) | These antibodies flag platelets for destruction by the spleen |
| Anti-platelet antibodies (directed at GPIb/IX) | These antibodies flag platelets for destruction by the spleen |
Citations
- Neunert C, et al. The American Society of Hematology 2019 guidelines for immune thrombocytopenia. Blood Adv. 2019;3(23):3829-3866.
- Provan D, et al. Updated international consensus report on the investigation and management of primary immune thrombocytopenia. Blood Adv. 2019;3(22):3780-3817.
- Zufferey A, et al. Pathogenesis and therapeutic mechanisms in immune thrombocytopenia. J Clin Med. 2021;10(3):789.