Thrombotic Thrombocytopenic Purpura (TTP)
A rare blood emergency in which tiny clots form throughout the body
Quick Facts
- Type: Rare, serious blood disorder
- Problem: Widespread tiny blood clots
- Key signs: Bruising, fatigue, confusion, fever
- Urgency: Medical emergency — needs immediate care
Overview
Thrombotic thrombocytopenic purpura (TTP) is a rare but serious blood disorder in which small blood clots form in tiny blood vessels throughout the body. These clots use up platelets, leading to a low platelet count, and they damage red blood cells as they squeeze past, causing anemia. The clots can also block blood flow to organs such as the brain and kidneys.
TTP is a medical emergency. It usually results from a problem with an enzyme called ADAMTS13, which normally helps control clotting. Without prompt treatment, TTP can be fatal, but with early diagnosis and modern therapy, most people recover. It can occur once or come back in some individuals.
Symptoms
Symptoms can come on quickly and reflect both bleeding from low platelets and clots blocking blood flow. They may include:
- Easy bruising and tiny red or purple spots on the skin (petechiae)
- Fatigue and weakness from anemia
- Paleness or yellowing of the skin (jaundice)
- Confusion, headache, or changes in behavior
- Trouble speaking, weakness, or vision problems
- Fever
- Reduced urination or dark urine from kidney involvement
- Fast heartbeat and shortness of breath
TTP is an emergency. Seek immediate medical care for confusion, weakness, trouble speaking, severe bruising, or other sudden, serious symptoms.
Causes
TTP develops when there is a severe shortage of an enzyme called ADAMTS13, which normally breaks down a large clotting protein. Without enough of this enzyme, the clotting protein triggers abnormal clumping of platelets and tiny clots. Causes include:
- Acquired TTP: The most common form, caused by antibodies that block the ADAMTS13 enzyme. This is an autoimmune problem.
- Inherited (hereditary) TTP: A rare genetic deficiency of the enzyme, present from birth.
- Triggers: Pregnancy, infections, certain medications, cancer, and some medical conditions can set off episodes.
Risk Factors
- Being an adult, with acquired TTP more common in women
- Pregnancy
- Certain infections
- Some medications
- Other autoimmune conditions
- A family history of inherited TTP (for the hereditary form)
Diagnosis
Because TTP is an emergency, doctors often begin treatment based on strong clinical suspicion while tests are completed.
- Complete blood count: Shows low platelets and anemia.
- Blood smear: Reveals fragmented red blood cells (schistocytes) caused by clots.
- ADAMTS13 testing: Measures the enzyme level and looks for antibodies against it.
- Additional blood tests: To assess red cell breakdown, kidney function, and organ involvement.
Distinguishing TTP from other similar disorders is important because the treatments differ.
Treatment
TTP requires urgent, specialized hospital treatment, often in an intensive care setting.
- Plasma exchange (plasmapheresis): The mainstay treatment, which removes the harmful antibodies and replaces the missing enzyme using donor plasma. It is started as soon as possible.
- Corticosteroids and immune therapies: Used to suppress the antibodies in acquired TTP.
- Targeted medications: Newer drugs can help reduce harmful clotting during an episode.
- Plasma infusion: For inherited TTP, regular plasma can replace the missing enzyme.
Prompt treatment greatly improves survival, and ongoing monitoring helps catch any relapse early.
Prevention
TTP usually cannot be prevented, but relapses can be reduced and complications limited by:
- Attending all follow-up appointments to monitor blood counts and enzyme levels
- Recognizing early warning signs so treatment can start quickly
- For inherited TTP, receiving scheduled plasma to maintain enzyme levels
- Telling all healthcare providers about the diagnosis, especially before procedures or pregnancy
When to See a Doctor
Seek emergency care immediately if you or someone else has a combination of symptoms such as confusion, trouble speaking, weakness, severe bruising or bleeding, fever, and extreme fatigue, especially if they come on suddenly. TTP can be life-threatening and needs urgent treatment.
If you have a history of TTP, contact your care team right away at the first sign of returning symptoms.
Frequently Asked Questions
Is TTP a medical emergency?
Yes. TTP is a life-threatening emergency. Without prompt treatment it can be fatal, but early plasma exchange and other therapies allow most people to recover. Sudden confusion, weakness, severe bruising, or bleeding need immediate medical care.
What is the difference between TTP and ITP?
Both involve low platelets, but they are different conditions. In ITP, the immune system simply destroys platelets, causing bruising and bleeding. In TTP, tiny clots form throughout the body, which uses up platelets, damages red blood cells, and can block blood flow to organs, making it far more urgent.
What causes TTP?
Most cases are caused by antibodies that block an enzyme called ADAMTS13, which normally controls clotting. A rare inherited form is caused by a genetic shortage of the same enzyme. Triggers such as pregnancy, infections, and certain medications can set off episodes.
Can TTP come back after treatment?
Yes, especially the acquired form. Some people have one episode, while others experience relapses. Regular follow-up and recognizing early warning signs allow prompt treatment if it returns.
How is TTP treated?
The main treatment is plasma exchange, which removes harmful antibodies and replaces the missing enzyme. Corticosteroids, immune-suppressing therapies, and newer targeted medications are also used. Treatment is started urgently in the hospital.
References
- National Heart, Lung, and Blood Institute (NHLBI). Thrombotic Thrombocytopenic Purpura.
- MedlinePlus, U.S. National Library of Medicine. Thrombotic thrombocytopenic purpura.
- National Organization for Rare Disorders (NORD). Thrombotic Thrombocytopenic Purpura.
- American Society of Hematology. Thrombotic Thrombocytopenic Purpura (TTP).