“Starting the plasma exchange is certainly what is most important...”

Key Points

  • For Acquired TTP, there are two types of treatment that are used together: Plasma exchange therapy and Immunosuppression
  • These treatments aim to remove antibodies from the blood, replace ADAMTS13 and stop the formation of new antibodies
  • For inherited TTP, treatment involves plasma infusion which aims to replace the ADAMTS13 in the plasma
  • For all TTP patients, regular follow-up and monitoring may be required

Acquired TTP

There are currently two types of treatments used to treat acquired TTP. The first type of treatment is plasma exchange therapy. With plasma exchange, the goal is to remove the antibodies that block the ADAMTS13 enzyme and replace the ADAMTS13 enzymes in the blood. The second type of treatment is a medicine called an immunosuppressant. This type of treatment aims to stop the immune system from producing new antibodies against ADAMTS13.

Inherited TTP

The main treatment for patients with inherited TTP is an infusion of donor plasma, also called fresh frozen plasma. The aim of the treatment is simple: to replace the ADAMTS13 enzyme in the patient’s plasma. Fresh frozen plasma contains the normal levels of ADAMTS13 enzyme so when it is infused into a patient with inherited TTP, it replaces the patients’ missing or damaged ADAMTS13 enzymes and allows the patients’ blood levels return to normal. Because patients with inherited TTP do not have antibodies to ADAMTS13, plasma exchange and immunosuppression are not necessary.

Plasma Exchange Therapy

Plasma exchange therapy (sometimes also called plasmapheresis) is an important treatment for patients with acquired TTP. To understand how plasma exchange works, it is important to know a little about the different components that make up your blood.

Blood has four main components:

  1. Red blood cells, which help carry oxygen around the body
  2. White blood cells, which help fight infections
  3. Platelets, which help form blood clots if bleeding occurs
  4. Plasma, the liquid part of the blood, which helps transport blood cells, platelets and other substances (antibodies and nutrients) throughout the body.

In patients with aTTP, a critical part of treatment is to remove the antibodies in the blood that block the ADAMTS13 enzyme. These antibodies are contained in the blood plasma.

During plasma exchange, blood is taken out of a vein and goes into a machine that separates the plasma from the blood cells and platelets. The blood cells and platelets are combined with donated plasma and returned to your body. Only a small portion of your blood is removed at any time so the whole process will take several hours.

Plasma exchange is normally repeated every day until the antibodies are no longer present in your blood and your platelet count is back to normal. The length of time for this to happen varies widely from patient to patient – for some, it may be days of treatment, for others, it may be up to several weeks.

Guidelines on the diagnosis & management of TTP

A technical paper published in British Journal of Haematology