What is ITP?
ITP - Immune thrombocytopenia, also known as immune or idiopathic thrombocytopenic purpura, 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.
While some cases of ITP are caused by drugs and others are associated with infection, pregnancy, or immune disorders such as systemic lupus erythematosus, about half of all cases are classified as "idiopathic," meaning the cause is unknown.
The main symptom is bleeding which can include bruising ("ecchymosis") and 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.
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 (CDC) will be done to quantifying the numbers for each type of blood cells including platelets. A low platelet count will establish thrombocytopenia as the cause of purpura. Often the next procedure is a bone marrow examination 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). Another blood sample may be drawn to check for other conditions sometimes associated with thrombocytopenia such as lupus and infection.
If the doctor thinks a drug is the cause of the thrombocytopenia, standard treatment involves discontinuing the drug's use. Infection, if present, is treated vigorously since control of the infection may result in a return of the platelet count to normal. The treatment of idiopathic thrombocytopenic purpura 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) and/or intravenous infusions of immune globulin (IVIG). Another treatment that usually results in an increased number of platelet is removal of the spleen, the organ that destroys antibody-coated platelet. Other drugs such as vincristine, azathioprine (Imuran), Danazol, cyclophosphamide, and cyclosporine are prescribed for patients only in severe cases where other treatments have not shown benefit, since these drugs have potentially harmful side effects. Except in certain situations (e.g., internal bleeding and preparation for surgery), platelet transfusions usually are not beneficial. Because all therapies can have risks, it is important that overtreatment (treatment based solely on platelet counts and not on symptoms) be avoided. In some instances lifestyle adjustments may be helpful for prevention of bleeding due to injury. These would include use of protective gear such as helmets and avoidance of contact sports in symptomatic patients or when platelet counts are less than 50,000. Otherwise, patients usually can carry on normal activities, but final decisions about activity should be made in consultation with the patient's hematologist.