What is ITP?

ITP stands for Immune Thrombocytopenia, also known as Immune or Idiopathic Thrombocytopenic Purpura. ITP is a rare bleeding disorder characterized by a low amount of platelets in the blood. Platelets are needed for clotting of the blood.

In patients with ITP, a person's own immune system creates antibodies that mark healthy platelets as "foreign substances" and then mistakenly attack and destroy them. As an autoimmune disease that results in the destruction of platelets, patients with ITP have a tendency to bleed or bruise.

Definitions:

  • Immune refers to the immune system's involvement in this disorder. Antibodies, part of the body's immunologic defense against infection, attach to blood platelets (cells that help stop bleeding), and cause their destruction.
  • Thrombocytopenia refers to decrease in blood platelets.
  • Purpura refers to the purplish-looking areas of the skin and mucous membranes (such as the lining of the mouth), where bleeding has occurred as a result of decreased platelet.

While some cases of ITP are caused by drugs, infection, pregnancy, or immune disorders such as Systemic lupus Erythematosus. However, about half of all cases are classified as idiopathic, meaning the cause is unknown.

Symptoms

  • Bleeding, which can include bruising (ecchymosis)
  • Tiny red dots on the skin or mucous membranes (petechiae)
  • In some instances bleeding from the nose, mouth and gums, digestive or urinary tracts may also occur
  • Rarely, bleeding within the brain occurs

Diagnosis

The physician will take a medical history and perform a thorough physical examination. A careful review of medications the patient is taking is important because some drugs can be associated with thrombocytopenia. A complete blood count (CBC) will be done to quantify the numbers for each type of blood cell including platelets.

A low platelet count will establish thrombocytopenia as the cause of purpura. Another blood sample may be drawn to check for other conditions sometimes associated with thrombocytopenia, such as lupus and infection. Sometimes a procedure, such as a bone marrow examination, is done to verify that there are adequate platelet-forming cells (megakaryocyte) in the marrow and to rule out other diseases, such as metastatic cancer (cancer that has spread to the bone marrow) and leukemia (cancer of the blood cells themselves).

Forms of ITP

Acute (transient) thrombocytopenic purpura is most commonly seen in young children. Boys and girls are equally affected. Symptoms often, but do not necessarily, follow a viral infection. About 85 percent of children recover within 1 year and the problem doesn't return.

Thrombocytopenic purpura is considered chronic when it has lasted more than 6-12 months. The onset of illness may be at any age. Adults more often have the chronic disorder and females are affected two to three times more than males. The onset of illness may be at any age.

  • Primary ITP, also know as Idiopathic, is when ITP develops for no known reason.
  • Secondary ITP is associated with other illnesses such as an infection or autoimmune disease, or occur after transfusion or taking certain drugs, for instance cancer drugs.

Treatment

If the doctor thinks a drug is the cause of the thrombocytopenia, standard treatment involves discontinuing the drug's use. If infection is present, it's treated vigorously. Control of the infection may result in a return of the platelet count to normal.

The treatment of ITP is determined by the severity of the symptoms. In some cases, no therapy is needed. In most cases, drugs that alter the immune system's attack on the platelet are prescribed. These include:

  • Corticosteroids (i.e., prednisone)
  • Intravenous infusions of immune globulin (IVIG). Except in certain situations (e.g., internal bleeding and preparation for surgery), platelet transfusions usually are not beneficial and therefore, are seldom performed.
  • Platelet growth factors or immune suppressants

Because all therapies can have risks, it is important that over-treatment be avoided. In some instances lifestyle adjustments may be helpful for prevention of bleeding due to injury. Otherwise, patients usually can carry on normal activities, but final decisions about activity should be made in consultation with the patient's hematologist.