Thrombotic Thrombocytopenic Purpura
Thrombotic thrombocytopenic purpura (TTP) is a rare disorder that involves your blood’s tendency to clot. In this disease, tiny clots form throughout your body. These tiny clots have two major consequences.
First, the tiny clots can block blood vessels. This stops your blood from being able to reach your organs. This can compromise the functioning of your vital organs—such as the heart, brain and kidneys.
Second, the tiny clots can use up too many of your blood’s platelets. Your blood might then be unable to form clots when it actually needs to. For example, if you are injured, you may be unable to stop bleeding.
What Causes Thrombotic Thrombocytopenic Purpura?
There is an inherited form of TTP that is transmitted as an autosomal recessive trait. This means that both parents of an affected individual must carry a copy of the defective gene. The parents do not usually have symptoms of the disease. This genetic form results from a mutation in the ADAMTS13 gene. This gene plays a role in the production of an enzyme that causes your blood’s ability to clot normally. When this enzyme is not produced, abnormal clotting occurs. Enzymes are special proteins that increase the rate of metabolic chemical reactions.
In other cases, your body mistakenly produces proteins that interfere with the enzyme’s job. This is called acquired TTP.
You can get acquired TTP in a variety of ways. You can develop it if you have HIV, for example. You can also develop it after various medical procedures, including:
- blood and marrow stem cell transplant
- bone marrow transplant
In some cases, TTP can develop during pregnancy or if you have cancer or an infection.
Some medications can lead to TTP. These include, but are not limited to:
- hormone therapy
- cyclosporine A
What Are the Symptoms of Thrombotic Thrombocytopenic Purpura?
If you have TTP, you might notice bruises that are purplish in color and have no obvious cause. These marks, called purpura, are part of what gives this condition its name. You might also have tiny red or purple spots that might look like a rash.
Your skin may change color. It might turn yellowish (jaundice), or you may look pale.
You might feel some general nonspecific symptoms such as:
In very serious cases, you might have a stroke or major internal bleeding. You might even fall into a coma.
How Is Thrombotic Thrombocytopenic Purpura Diagnosed?
Diagnosing TTP usually requires multiple tests.
Your doctor may begin by performing a physical exam. This involves looking for any of the physical symptoms that the disease can cause.
Your doctor will also test your blood. An examination of your red blood cells under a microscope will reveal whether they have been damaged by TTP. Your doctor will also check your blood for low platelet levels (the increased clotting causes increase use of platelets) or high levels of bilirubin (a substance that results from the breakdown of red blood cells).
Your blood might also be checked for:
- antibodies—proteins that interfere with the enzyme ADAMTS13
- creatinine—elevation of this breakdown product of muscles occurs if there is kidney involvement
- lack of ADAMTS13 enzyme activity—lack of this enzyme causes TTP
- lactate dehydrogenase (LDH)—LDH is released from tissues that are injured by blot clots from TTP
How Is Thrombotic Thrombocytopenic Purpura Treated?
TPP is typically treated by attempting to return your blood clotting to normal.
Plasma (the liquid portion of blood that contain essential clotting factors) can be given in the form of fresh frozen plasma. This can be given intravenously through a vein. This is the usual treatment for inherited TTP.
An alternative treatment that is commonly used is for acquired TTP is plasma exchange. This means that your plasma is replaced with the plasma of a healthy donor. During this procedure, the blood is taken out of your body through a tube in the same way as when you donate blood. The plasma is then separated out of that blood using a special machine called a cell separator. The plasma from your blood is disposed of and donated plasma is added to the your remaining blood. This solution is then given back to you through another IV (intravenously). The donated plasma contains water, proteins and essential clotting factors. This procedure takes about two hours.
Regardless of whether you have inherited or acquired TTP, you will generally need to have your procedure done every day until your condition improves.
If this treatment is not successful, your doctor may begin to treat you with medications to stop your body from destroying the ADAMTS13 enzyme.
In other cases, you might need to have your spleen surgically removed.
What Is the Long-Term Outlook for Thrombotic Thrombocytopenic Purpura?
With prompt and proper treatment, you will typically recover well from this condition.
Some people’s TTP goes away completely after treatment. Other people may have ongoing flare-ups.
TTP may lead to death if it is not found and treated right away. If you think you might have this condition, don’t delay in getting to your doctor or the emergency room.