Adult Immune Thrombocytopenic Purpura (ITP)

What is Adult Chronic Immune Thrombocytopenic Purpura?

Adult chronic immune thrombocytopenic purpura (chronic ITP) is an autoimmune disorder in which patients produce antiplatelet autoantibodies and specialized white blood cells that destroy their blood platelets and, in some cases, damage their megakaryocytes (the cells that produce platelets in the bone marrow), causing a decrease in platelet production. This results in a low blood platelet count (thrombocytopenia) that may produce bruising or excessive bleeding. The present information has been prepared to help adult patients better understand this condition. However, for specific questions about chronic ITP and recommendations concerning treatment, patients should contact their physicians.

Clinical findings. Patients may have no symptoms and the low platelet count may be noted during routine blood studies. However, most patients see their doctor because they develop a skin rash on their legs (called petechiae, a collection of small pinpoint bruises), excessive bruising or, less commonly, bleeding from the nose, gums or rarely from the gastrointestinal tract (stomach or bowel) or genitourinary tract (blood in the urine). Women may note prolonged or heavy menstrual bleeding. Symptoms may be exagerrated by certain medications which interfere with platelet function (e.g., aspirin, ibuprofen).

Laboratory findings. The blood count is normal except for a low platelet count (a normal platelet count in our laboratory is 130,000 to 400,000). Occasionally, patients are anemic if significant bleeding has occurred. Bone marrow examination is normal except that the number megakaryocytes (the cells which produce platelets) is often increased since the body is attempting to respond to the destruction of platelets by increasing their production. Autoantibodies against platelets can be detected in most patients. In chronic ITP, all other laboratory tests should be normal (including tests to rule out HIV, hepatitis or cytomegalovirus infection).