Immune Thrombocytopenia Purpura

Definition

Immune thrombocytopenia purpura (ITP) is a bleeding disorder. It is a reduction in the number of platelets in your blood. Platelets are small cells in your blood that stick together to form blood clots. These clots help stop bleeding at injury sites. Low platelet levels with ITP makes it easier to develop bruises or bleed even with minor injuries.

There are two types of ITP:

  • Acute ITP
    • Lasts less than six months.
    • Usually occurs in children.
    • Most common type of ITP.
  • Chronic ITP
    • Lasts longer than six months.
    • Usually occurs in adults.

Causes

ITP is caused by a problem with the immune system. The immune system places a tag on platelet cells. This tag mistakenly identifies platelets as foreign material. Organs like the spleen and liver will then remove the tagged platelets as they pass through in the blood. Gradually, this process will reduce the number of platelet in your blood. Eventually, the decreased levels of platelets will be severe enough to interfere with the blood's ability to clot.

Spleen
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For most ITP, it is not clear what causes the problem with immune system. In children, ITP is often associated with a recent infection with a virus. ITP in adults has not been linked to viruses.

Some cases of ITP are thought to be caused by drugs or other immune disorders.

Risk Factors

Factors that may increase your chances of developing ITP include:

  • Children with a recent viral infection or live virus vaccination
  • Women—2-3 times more likely to get ITP than men
  • Women younger than 40

Symptoms

Both adults and children may notice the following symptoms:

  • Easy bruising
  • Blood in urine or stools
  • Bleeding for longer than normal following an injury
  • Unexplained nosebleeds
  • Bleeding from the gums
  • In adult women, heavier-than-normal menstrual periods
  • Red dots—may occur in groups and resemble a rash
  • Bleeding within the intestinal tract or brain—rare

Diagnosis

Your doctor will ask about your symptoms and medical history. A physical exam will be done.

Blood tests will be done. The doctor may use these test to:

  • Analyze levels of different blood cells, including platelets
  • Test your blood's clotting ability
  • Look for infections or other medical issues associated with ITP
  • Eliminate other medical conditions

Platelets are created in your bone marrow. If your platelets are low, then your doctor may sample your blood marrow. This is done to eliminate conditions that may be interfering with the production of platelet cells.

Treatment

Treatment for ITP is different for children and adults. ITP is short term in most children. Most children will recover without any treatment. Adults are more likely to develop a chronic form of ITP. Not all of these chronic ITPs will require treatment. Talk with your doctor about the best plan for you.

Some treatment options include:

Medications

Medication may help to either slow the destruction of platelet cells or increase production of platelets. The overall goal is to maintain a healthy level of platelets in the blood.

To increase platelet counts in the blood, your doctor may recommend:

  • Steroids to lower the activity of the immune system. This will decrease the destruction of platelets.
  • Gamma globulin infusions to slow down platelet destruction. An infusion means that it is given by IV or through a shot. It usually works more quickly than steroids.

Both of these treatments work, but both can have side effects.

Two drugs are being used to stimulate platelet production:

  • Eltrombopag
  • Romiplostim

Use of these and a medication called rituximab may prevent the need for surgery.

Platelet Transfusion

A platelet transfusion may be used to prevent the platelet count from dropping too low.

Surgery

A splenectomy may be done if medication is not effective.

A splenectomy is the removal of the spleen. The spleen is the main site of platelet destruction. Without your spleen, your platelet levels should begin to improve. However, the missing spleen also makes you more likely to get certain infections. This surgery is usually not done until all medication options have been tried.

Activity Changes

You may be asked to avoid certain activities when your platelet counts are low. This may include avoiding contact sports or wearing a helmet.

Prevention

Since the cause of ITP is unknown, there are no specific ways of preventing it. However, bleeding and injury can be serious for people with ITP. To decrease the chance of bleeding injuries:

  • Take precautions in your child's environment. Consider padding an infant's crib or play area.
  • Make sure that older children wear helmets and protective gear when playing sports. This will help to reduce bruising injuries.
  • Consider temporarily stopping contact sports such as football and rough game playing when platelet counts are low.
  • Avoid medications that contain aspirin or ibuprofen. These medicines can reduce platelet activity.

Revision Information

  • American Academy of Family Physicians

    http://www.familydoctor.org

  • National Heart, Lung, and Blood Institute

    http://www.nhlbi.nih.gov

  • Canadian Medical Association Journal

    http://www.cmaj.ca

  • Health Canada

    http://www.hc-sc.gc.ca

  • Bussel JB; Cheng G; et al. Eltrombopag for the treatment of chronic idiopathic thrombocytopenic purpura. N Engl J Med. 2007 Nov 29;357(22):2237-2247.

  • Immune thrombocytopenia (ITP). EBSCO DynaMed website. Available at: https://dynamed.ebscohost.com/about/about-us. Updated March 28, 2013. Accessed July 11, 2013.

  • George JN, Woolf SH, et al. Idiopathic thrombocytopenic purpura: a practice guideline developed by explicit methods for The American Society of Hematology. Available at: http://www.ouhsc.edu/platelets/itp/ITP%20Publications/pub2%5F1.pdf. Accessed July 11, 2013.

  • Karpatkin S. Autoimmune (idiopathic) thrombocytopenic purpura. Lancet. 1997;349:1531-1536.

  • Newland A, Caulier MT, et al. An open-label, unit dose-finding study of AMG 531, a novel thrombopoiesis-stimulating peptibody, in patients with immune thrombocytopenic purpura. Br J Haematol. 2006 Nov;135(4):547-553.

  • What is immune thrombocytopenia? National Heart Lung and Blood Institute website. Available at: http://www.nhlbi.nih.gov/health/health-topics/topics/itp/. Updated March 14, 2012. Accessed July 11, 2013.