Patient guide

Understanding TTP

Thrombotic thrombocytopenic purpura (TTP) is a rare blood disorder that can become serious very quickly. This page explains what is happening, what doctors look for, how TTP is treated, and what comes next after an acute episode.

Newly diagnosed with TTP? Start here Newly diagnosed with CM-TMA / aHUS? Find TMA care

TTP can be a medical emergency. If you have severe or rapidly worsening symptoms, or symptoms you have been told could signal a relapse, seek urgent medical care. USTMA does not provide emergency medical care.

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TTP in 60 seconds

What is happening in the blood?

TTP is easier to understand when you break it into three connected problems.

ADAMTS13 becomes very low

ADAMTS13 is a protein that helps control von Willebrand factor, a protein involved in blood clotting. In TTP, ADAMTS13 activity becomes severely reduced.

Tiny clots can form

Without enough working ADAMTS13, platelets can collect in very small blood vessels and reduce blood flow to important organs.

Platelets fall and red cells are damaged

Platelets are used up in the small clots, while red blood cells can break apart as they move through affected vessels.

Watch

What is TTP?

A short introduction can make the terminology easier to understand before you move into the details below.

Why it happens

There are two main forms of TTP.

The difference is why ADAMTS13 is low.

Most adult cases

Immune TTP (iTTP)

The immune system makes an antibody that interferes with ADAMTS13. This is an autoimmune form of TTP.

Learn about iTTP →

Inherited / hereditary

Congenital TTP (cTTP)

A person is born with changes in the ADAMTS13 gene that prevent the body from making enough working ADAMTS13.

Explore patient resources →

Recognizing symptoms

TTP can look different from person to person.

Symptoms may come from low platelets, anemia, or reduced blood flow to organs.

Extreme fatigueFeeling unusually weak or exhausted

Bruising or small red/purple spotsPurpura or petechiae can occur when platelets are low

BleedingSuch as nose or gum bleeding

Headache or neurologic changesConfusion, vision changes, difficulty speaking, weakness or seizures can occur

Chest symptomsChest pain, shortness of breath or other cardiac symptoms need urgent evaluation

Digestive symptomsAbdominal pain, nausea or diarrhea may occur

FeverSome people develop fever during an acute episode

Symptoms can be subtleYou do not need to have every classic symptom for TTP to be possible

When symptoms feel urgent

Do not use a website to decide whether a possible TTP relapse is safe to watch at home. Follow the emergency plan your TTP team gave you. For severe, new or rapidly worsening symptoms, seek emergency medical evaluation.

How TTP is diagnosed

Doctors look at the whole picture—not one test alone.

ADAMTS13 is central to confirming TTP, but treatment may need to begin before the result returns.

Blood counts

A CBC shows whether the platelet count is low and whether anemia is present.

Blood smear & hemolysis tests

A blood smear may show damaged red blood cells called schistocytes. LDH, bilirubin, haptoglobin and other tests help determine whether red blood cells are breaking apart.

ADAMTS13 testing

ADAMTS13 activity testing helps confirm TTP. Your team may also test for an inhibitor or antibody to help identify immune TTP.

Organ assessment

Doctors may check the kidneys, heart, brain and other organs depending on your symptoms and laboratory findings.

One important point: if doctors strongly suspect TTP, treatment should not be delayed just because the ADAMTS13 result is still pending.

Treatment

Acute iTTP usually requires several treatments working together.

Your treatment plan is individualized. These are the therapies patients commonly hear about during an acute iTTP episode.

PEX

Plasma exchange

Plasma exchange removes harmful antibodies and replaces plasma containing working ADAMTS13. It is a central treatment for acute immune TTP.

Corticosteroids

Steroids help suppress the autoimmune process that is interfering with ADAMTS13.

VWF

Caplacizumab

Caplacizumab targets von Willebrand factor and can help reduce formation of the small platelet-rich clots seen in acute iTTP.

Rituximab

Rituximab targets B cells and may be used to control the immune response responsible for ADAMTS13 antibodies.

This patient page intentionally does not provide medication doses or a treatment schedule. Treatment decisions belong with your hematology team and may differ depending on your situation. Clinicians can use the USTMA TTP Clinical Guidance resource.

After an acute episode

Recovery is more than a normal platelet count.

Follow-up matters because relapse can occur and some effects of TTP may continue after discharge.

Keep follow-up appointments

Your hematology team may continue monitoring ADAMTS13 and other laboratory values after remission.

Know your relapse plan

Ask which symptoms should trigger a call to your TTP team and which should send you directly to emergency care.

Talk about fatigue and cognition

Some survivors report persistent fatigue, memory or concentration problems, headaches, anxiety or depression. These concerns are worth discussing with your care team.

Think beyond TTP labs

Long-term follow-up may also include cardiovascular health, blood pressure, pregnancy planning and other needs specific to you.

USTMA can help

Choose the next step that fits what you need today.

New diagnosis

For healthcare professionals

Looking for detailed clinical guidance?

The clinician resource includes diagnostic testing, acute management, ADAMTS13 monitoring, remission follow-up and evidence links.

Open TTP Clinical Guidance