Have you heard of the rare autoimmune bleeding disorder known as ITP? The abbreviation stands for immune thrombocytopenia — a condition that’s hard to spell, harder to pronounce, and probably something you’ve only heard of if you know someone who has it.
Here’s what you need to know about ITP causes, diagnosis, and treatment:
What Is ITP?
Immune thrombocytopenia (ITP) — which was previously known as idiopathic thrombocytopenic purpura or immune thrombocytopenic purpura — is an autoimmune bleeding disorder where your immune system mistakenly attacks and destroys your platelets, the tiny, irregularly shaped blood cells that play a crucial role in blood clotting.
When an injury occurs and a blood clot is needed, the platelets become sticky and help plug the site of the injury. They attract other proteins in the clotting process to form a stable clot.
With ITP, the immune system mistakenly generates antibodies that attach to platelets and mark them for destruction by the spleen and liver, and the blood isn’t able to clot normally. In addition, bone marrow may also make fewer platelets — and the spleen may trap and hold more than usual.
ITP can be acute (short term) or chronic (long term). Acute ITP often lasts less than 12 months. It mainly affects children, sometimes following a viral infection such as flu or mumps, and is the most common type of ITP.
Chronic ITP mostly affects adults and lasts 12 months or longer. It can occur after a viral infection, with use of certain medicines, during pregnancy, or as part of an immune disorder. According to the National Heart, Lung, and Blood Institute, chronic ITP affects women two to three times more often than men.
ITP affects at least 3,000 children under age 16 each year in the U.S., with most being 2 to 6 years old when diagnosed, according to the Platelet Disorder Support Association. An estimated 50,000 adults in the U.S. are currently living with the chronic form of ITP.
The most common symptoms of ITP include small red or purple spots on the skin (called petechiae), easy or unexplained bruising, frequent nosebleeds, or bleeding gums, especially after dental work. Women may have heavier or longer periods than usual. ITP can also cause tiredness and affect day-to-day life. In rare cases, it can become very serious or even life-threatening.
How Is ITP Diagnosed?
There is no single test for ITP, so the condition is usually diagnosed when other factors are ruled out, such as underlying illnesses or medications, and low platelet counts persist.
In addition to a full medical history and exam, doctors will typically order the following tests:
- Complete blood count: This test measures, counts, evaluates, and studies certain aspects of your blood, including the amount of hemoglobin, the size and number of red blood cells, and the number of different types of white blood cells and platelets found in the blood.
- Blood smear: This test is used to confirm the number of platelets observed in a complete blood count.
- Bone marrow exam: If blood tests show your platelet count is low, your doctor may recommend you have a bone marrow test to show whether your bone marrow is making enough platelets. However, this test is usually not recommended for children suspected of having ITP.
Treatments for ITP
Many children with ITP recover on their own within weeks or months. So in many cases, children are given regular blood tests to monitor their platelet levels, but no treatment is necessary.
Adults with ITP are usually given a steroid medicine (either prednisone or dexamethasone), which suppresses the immune system to reduce platelet destruction. Another possible treatment for ITP is intravenous immunoglobulin (IVIG). This type of antibody treatment provides a quick, short-term boost to platelet count, which is useful in acute bleeding or before surgery. People who have Rh-positive blood are candidates for an intravenous drug infusion called Anti-RhoD, which works similarly to IVIG but is cheaper and has a shorter infusion time.
Other possible treatments for ITP include medicines called thrombopoietin receptor agonists, or TPO-RAs, which help your bone marrow produce more platelets, and immunosuppressants such as azathioprine and cyclosporine.
If medications aren’t effective, doctors may recommend surgery to remove the spleen, which is called a splenectomy. People without a spleen need to take extra precautions against infection because of reduced immunity.
If you have ITP, you need to avoid aspirin, ibuprofen, and warfarin, since these medicines can affect how platelets work or how blood clots — making bleeding more likely.