What is immune thrombocytopenia?

Immune thrombocytopenia is a common bleeding disorder in which blood does not clot as it should due to a low number of platelets or thrombocytes.

The condition also is known as idiopathic thrombocytopenic purpura, immune thrombocytopenic purpura or autoimmune thrombocytopenic purpura.

Causes

Immune thrombocytopenia (ITP) occurs in both children and adults. In most cases, an autoimmune response is thought to cause the condition. However, the disorder has been linked to viral or bacterial infections, including HIV, hepatitis C and helicobacter pylori.

Children tend to have acute ITP, which normally develops after a viral infection. Adults tend to have chronic ITP.

Women are more likely than men to develop chronic ITP.

Symptoms and detection

Although ITP may not cause any signs or symptoms, internal or external bleeding does occur.

Bruises or purpura — purplish areas on the skin — may occur. Small red spots known as petechiae also may appear on the skin. These red pinpoint spots may appear to be a rash, but they are caused by bleeding under the skin.

Other symptoms of ITP include hematomas and fatigue.

Routine blood tests for ITP are becoming more common; therefore, the number of diagnosed cases has increased. If a blood test shows a low platelet count, a physician may recommend additional tests to confirm.

Treatment and outcomes

Treatment for ITP is individualized. It is based upon platelet count and bleeding frequency.

Acute ITP often subsides in children within a few weeks or months. Adults with mild ITP may not require treatment and only might require close monitoring for symptoms and changes in platelet counts. Both children and adults with very low platelet counts or bleeding should be treated.

Treatment consists of corticosteroids, such as prednisone. In some cases, steroids are associated with side effects. Some patients may relapse when treatment is stopped.

Other treatments may be administered via IV to increase platelet count. These include rituximab (Rituxan; Genentech, Biogen), immune globulin and anti-Rh immunoglobulin. In some cases, splenectomy is necessary.

If medications or splenectomy do not work, patients may be prescribed one of two newer medications, eltrombopag (Promacta, Novartis) or romiplostim (Nplate, Amgen).

Other treatments consist of platelet transfusions, treating the infection or stopping other medications that may be lowering platelet counts.

Although immune thrombocytopenia cannot be prevented, a person can take measures to help prevent complications. For example, changes in lifestyle and adhering to recommended follow-up care are key.

Women with mild cases of ITP who are pregnant usually go through pregnancy with no need for treatment. Those with low platelet counts or those who experience heavy bleeding are at higher risk for heavy bleeding during birth and thereafter, and they require treatment for these complications.

Research into ITP treatment is ongoing. For information about clinical trial participation, go to www.clinicaltrials.gov, www.nhlbi.nih.gov/studies/index.htm or www.researchmatch.org.

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