Thrombotic thrombocytopenic purpura is a rare disorder that causes blood clots (thrombi) to form in small blood vessels throughout the body. These clots can cause serious medical problems if they block vessels and restrict blood flow to organs such as the brain, kidneys and heart. Complications from these clots can include neurological problems (such as personality changes, headache, confusion, and slurred speech), fever, abnormal kidney function, abdominal pain, and heart problems. Blood clots usually form at sites of blood vessel injury to prevent blood loss. In people with thrombotic thrombocytopenic purpura, clots develop even in the absence of obvious injury. Blood clots form from clumps of cells called platelets that circulate in the blood and help form clots. Because a large number of platelets are used to form clots in people with thrombotic thrombocytopenic purpura, there are fewer platelets available in the bloodstream. Low levels of circulating platelets are known as thrombocytopenia. Thrombocytopenia can lead to small areas of bleeding beneath the surface of the skin, resulting in purple spots called purpura. This disorder causes red blood cells to break down prematurely (undergo hemolysis). As the blood squeezes past clots within the blood vessels, the red blood cells may separate. A condition called hemolytic anemia occurs when red blood cells are destroyed faster than the body can. This type of anemia causes pallor, yellowing of the eyes and skin (jaundice), fatigue, shortness of breath, and rapid heart rate. There are two major forms of thrombotic thrombocytopenic purpura, an acquired (non-inherited) form and a familial (inherited) form. The acquired form usually appears in late childhood or adulthood. Affected individuals may have a single episode of signs and symptoms, or more commonly, they may experience multiple recurrences over time. The familial form of this disorder is very rare and usually appears in infancy or early childhood, although it may appear later in life. In people with the familial form, signs and symptoms often occur on a regular basis and may return in times of stress, such as during illness or pregnancy.
Symptoms of TTP occur because abnormally developing clots in the blood vessels in the organs prevent the organs from functioning properly. As platelets are used to clot abnormally, other areas of the body may experience bleeding. Red blood cells are also damaged in the process, and low platelets in combination with blood clots and damaged red blood cells can cause a variety of symptoms.
Symptoms of TTP may include:
Plasma exchange: Treating TTP usually requires a treatment called plasma exchange. During plasma exchange, blood is drawn from a person with TTP and filtered through a special machine. In this machine, the plasma is taken out, removing the antibodies responsible for causing the disease. Other blood products, such as red blood cells and platelets, are returned to the patient.
Medication: There are some drugs that may be used to treat TTP, often in combination with plasma exchange. These drugs, such as steroids as well as Rituxan and caplacizumab, work by suppressing the immune system and stopping the process that causes disease. Sometimes chemotherapy drugs may be given to treat TTP.
Surgery: The only surgical treatment for TTP is splenectomy – or surgical removal of the spleen. This can be an effective treatment, as the spleen is responsible for making antibodies that prevent the ADAMTS13 enzyme from working properly. Removal of the spleen can prevent these antibodies from being made.
Prognosis: It is possible that a person can fully recover from TTP and not have any long-lasting effects. However, there are some complications that can arise. These complications develop when the clots in the blood vessels cause permanent damage to an organ, such as the kidneys or brain. These blood clots can cause a stroke, and having a stroke has the potential to cause a permanent decrease depending on the location and severity of the stroke. Serious bleeding can occur with TTP, and can be potentially life-threatening if it is difficult to control. It is also possible that a person recovering from TTP may experience another episode in the future. If re-occurrence is suspected it is important to seek emergency evaluation and treatment so that treatment can be started as soon as possible to prevent long-term effects of the disorder.