About Thrombotic Thrombocytopenic Purpura
An enzyme in the blood called ADAMTS13 trims von Willebrand factor, a sticky protein that helps platelets form clots. When ADAMTS13 is missing, very long strands of von Willebrand factor grab platelets inside small blood vessels, forming tiny clots that use up platelets, break red blood cells and starve organs of blood. In immune TTP, the most common form, the body makes antibodies that block ADAMTS13. In congenital TTP, a person inherits 2 changed copies of the ADAMTS13 gene. Doctors confirm TTP with an ADAMTS13 activity test below 10%, plus an antibody test, and may use the PLASMIC score to judge the chance of TTP while results are pending.
Immune TTP is treated in the hospital. The International Society on Thrombosis and Haemostasis's 2020 guideline strongly recommends plasma exchange together with steroids, and suggests adding rituximab and Cablivi (caplacizumab), which stops platelets sticking to von Willebrand factor. Congenital TTP is treated with plasma infusions or with Adzynma, a lab-made ADAMTS13 enzyme the FDA approved on November 9, 2023. Adzynma now carries a boxed warning about antibodies that can block the enzyme, and the FDA has investigated a death from these antibodies after Adzynma treatment. Because TTP can come back, people who have had it need regular ADAMTS13 checks.
Common Symptoms of Thrombotic Thrombocytopenic Purpura
Recognizing the signs of Thrombotic Thrombocytopenic Purpura early can lead to faster diagnosis and better outcomes. Symptoms may vary in severity from person to person. If you or a loved one are experiencing any of the following, consider speaking with a specialist.
- Small red spots or purple bruises on the skin
- Pale or yellow skin or eyes
- Extreme tiredness
- Headache, confusion, changes in speech or seizures
- Passing little urine, or blood in the urine
Who Thrombotic Thrombocytopenic Purpura Affects
Immune TTP is more common in adults than in children, about 3 times more common in women than men and about 7 times more common in Black people than in others (2025 review); NORD notes it usually affects people aged 20 to 50. Congenital TTP is inherited, and in a registry of 87 patients symptoms began at a median age of 4.6 years while diagnosis came at a median age of 18.
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FDA-Approved Treatments for Thrombotic Thrombocytopenic Purpura
There are currently 2 FDA-approved medications for Thrombotic Thrombocytopenic Purpura. These therapies represent the current standard of care and may be used alongside or compared against investigational treatments in active clinical trials.
Source: openFDA drug labeling data. This list may not include all treatments. Always consult your doctor.
Help Paying for Thrombotic Thrombocytopenic Purpura Treatment
Charity funds and drugmaker programs for Thrombotic Thrombocytopenic Purpura, checked at the source.
- Cablivi (Caplacizumab) · Sanofi HemAssist
- Adzynma (ADAMTS13, recombinant-krhn) · Takeda Hematology Support Center
Side Effect Explorer
Real-world side effect reports from the FDA Adverse Event Reporting System (FAERS). Includes both FDA-approved drugs and investigational therapies from active clinical trials. Click any drug to see what patients reported.
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Diagnosis and Testing
Most TTP is immune and not inherited. Congenital TTP is autosomal recessive, caused by changes in both copies of the ADAMTS13 gene on chromosome 9 (MedlinePlus Genetics).
Trusted Thrombotic Thrombocytopenic Purpura Resources
Reputable organizations and medical references for learning more about Thrombotic Thrombocytopenic Purpura, including disease registries, foundation resources, and clinical guidelines.