What Is Thrombotic Thrombocytopenic Purpura (TTP)?

Thrombotic thrombocytopenic purpura (TTP) is a rare blood disorder in which clumping platelets cause clots to develop in small blood vessels in the organs of the body, which can result in failure of the affected organs.

As the platelets are used up in forming abnormal blood clots, they then become low in number in the blood. When the platelet levels fall due to abnormal clotting, they aren’t available when needed, and then bleeding, both internal and external, can occur. Many other symptoms can occur as well.

This article will review the symptoms of TTP as well as the causes, and how it is diagnosed and treated.

TTP Symptoms

Symptoms of TTP occur because the clots that develop abnormally in the blood vessels in the organs prevent the organs from functioning properly. As the platelets are used up in the abnormally formed clots, other areas of the body may experience bleeding.

Red blood cells are also damaged in the process, and the low platelets in combination with blood clots and damaged red blood cells can cause a variety of symptoms.

Symptoms of TTP may include:

• Nervous system: Headaches, vision changes, confusion, speech changes, seizures
• Urinary system: Kidney failure, swelling to the lower extremities, blood in the urine
• Skin: Purpura (purplish spots on the skin from bleeding), bruising, bleeding in the mouth, pale skin
• Other: Abnormal labs (anemia, electrolyte imbalances), nausea, vomiting, heavy menstrual bleeding, weakness, fatigue, abdominal pain, fever

Causes

An enzyme called ADAMTS13 is involved in the process of blood clotting. When the enzyme is too low, the blood clots too much. In TTP, there isn’t enough of the enzyme, either due to inherited or acquired causes.

Inherited TTP

Although the exact cause of TTP is not always known, it is often found to be associated with a deficiency in an enzyme called ADAMTS13. Without enough of this enzyme, excessive clotting of the blood can occur. This deficiency can be inherited if a child receives a copy of the defective gene from each of their parents.

Acquired TTP

With acquired TTP, the ADAMTS13 enzyme cannot function properly because the immune system has produced antibodies against the enzyme. This blocks the function of the enzyme and keeps it from working properly.

Sometimes other diseases or disorders such as cancer, HIV infection, stem cell transplant, and even some medications can make it more likely for TTP to develop. 

Diagnosis

A diagnosis of TTP is made by a physician through taking a medical history and performing a physical exam, symptom review, and a variety of blood tests. 

History and Physical

The physician will review the medical history, investigating any potential causes for the symptoms someone is experiencing. The provider will want to know if a person has a history of any factors that may make a TTP diagnosis more likely, such as a history of HIV infection, cancer, or stem cell transplant. A review of medications will also be done. Some medications associated with the development of TTP include:

• Ticlopidine
• Clopidigrel
• Cyclosporine A
• Hormone replacement
• Chemotherapy
• Quinine

Testing

Many lab tests are done to make a diagnosis of TTP.

• Complete blood count (CBC): Evaluates the number and sizes of white blood cells, red blood cells, and platelets in a sample of blood. In TTP, a lower than normal number of platelets is seen. People with TTP are also usually anemic (low number of red blood cells) in addition to being thrombocytopenia (low number of platelets).
• Bilirubin: The test for bilirubin, a byproduct of the breaking down of red blood cells, can be elevated in someone with TTP.
• Creatinine: A measure of kidney function, this lab can be elevated when kidneys are not functioning properly in someone with TTP. 
• Lactate dehydrogenase (LDH): This enzyme can be elevated as it is released from cells injured and damaged due to TTP. 
• Coombs test: This test result should be negative in someone with TTP, as this is typically positive when someone has a different disorder called autoimmune hemolytic anemia, when the body inappropriately breaks down red blood cells. 
• ADAMTS13 assay: This test determines the activity of the ADAMTS13 enzyme. In TTP, this enzyme level is lower than normal.  

Treatment 

Plasma Exchange

A treatment called plasma exchange is typically needed to treat TTP. During plasma exchange, blood from the person with TTP is removed and filtered through a special machine. In this machine, the plasma is taken out, removing the antibodies responsible for causing the disease. The other blood products, such as red blood cells and platelets, are returned to the patient.

Healthy plasma from a donor is then transfused. Plasma transfusion replenishes the ADAMTS13 level to correct the deficiency that caused the TTP. This is often repeated every day until the disease improves.

Medication

There are some medications that can be used to treat TTP, often in combination with plasma exchange. These medications, such as steroids as well as Rituxan and Caplacizumab, work by suppressing the immune system and stopping the process causing the disease. Sometimes chemotherapy medications may be given to treat TTP.

Surgery

The only surgical treatment for TTP is a splenectomy—or surgical removal of the spleen. This can be an effective treatment, as the spleen is responsible for making the antibodies that are causing the ADAMTS13 enzyme to not work properly. Removing 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 to occur, and having a stroke comes with the possibility of permanent deficits depending on the location and severity of the stroke. Severe bleeding can occur with TTP, and can potentially be life-threatening if it is difficult to control.

It is also possible that someone who recovered from TTP can experience another episode in the future. Seeking emergency evaluation and treatment if a relapse is suspected is important so that treatment can be initiated as quickly as possible to prevent long-term effects from the disorder.

A Word From Verywell

Having a diagnosis of TTP for yourself or a loved one can be a stressful time. It is important to remember that treatment options are available, and medical treatment should be sought promptly if any symptoms of this disorder develop. It is also important to ask your healthcare team any questions you have about TTP. That way, you can get the answers you need and ensure you’re comfortable and getting good care. 

Frequently Asked Questions

What are the symptoms of thrombotic thrombocytopenic purpura (TTP)?

The symptoms of TTP can include:

• Purpura (bleeding under the skin)
• Bleeding from the gums or nose
• Blood in the urine
• Fatigue
• Fever
• Headache
• Difficulty breathing

What does thrombotic thrombocytopenic purpura (TTP) look like? 

The purpura associated with TTP may appear as purple splotches under the skin. These can occur to any area of the body, including the inside of the mouth. Purpura is caused by bleeding under the surface of the skin.

What causes thrombotic thrombocytopenic purpura (TTP)? 

For TTP to develop, the enzyme ADAMTS13 does not function properly, and there is not enough in the body. Without enough of this enzyme, the blood can form too many clots. With inherited TTP, someone is born with low levels of this enzyme. In acquired TTP, the enzyme is blocked by the development of antibodies against it.

What does the acronym TTP mean?

TTP stands for thrombotic thrombocytopenic purpura. 

How is TTP diagnosed? 

TTP is diagnosed through taking a detailed medical history, performing a physical exam looking for changes associated with TTP, and through multiple blood tests. The blood tests can evaluate the number of blood cells as well as evaluate body organ function. An ADAMTS13 assay can be done as well to see if there is enough of that enzyme in the body.