What is TTP?
Thrombotic thrombocytopenic purpura (TTP) is a rare, life-threatening blood disorder. There are 2 main types of TTP: acquired or immune-mediated TTP (aTTP/iTTP*) and hereditary or congenital TTP (cTTP).
Acquired or immune-mediated thrombotic thrombocytopenic purpura (aTTP/iTTP) is a rare blood disorder that develops when the immune system stops ADAMTS13, a protein (an enzyme), from working properly. Without this protein, the body creates too many blood clots. This syndrome is characterized by anemia caused by damage to red blood cells accompanied by a low platelet count, neurologic symptoms, and renal disease.
In hereditary TTP, people are born with a faulty gene that causes TTP. Inherited TTP is very rare - it is estimated that only 5% of all cases of TTP are inherited TTP. On the other hand, most people who have TTP have aTTP/iTTP. This means they developed TTP later in their lives. Around 95% of all TTP cases are acquired/immune-mediated.
What happens during aTTP/iTTP?
One of the components in your blood that helps your platelets stick together is called von Willebrand factor (vWF). Platelets are small cells found in the blood and are involved in clotting. Their main job is to form blood clots when bleeding happens. Platelets stick together to seal a cut or injury. This stops bleeding. Normally, vWF is cut up into smaller pieces by an enzyme called ADAMTS13 after a bleed has healed.
In people with aTTP/iTTP, the body's immune system makes proteins called autoantibodies that stop ADAMTS13 from cutting up vWF.
These large molecules of vWF attract platelets. This forms blood clots even when there is no bleeding. These clots:
- Can block the flow of blood to important organs, such as the brain, heart, or kidneys. This can cause serious health problems, such as stroke or seizure
- Can destroy red blood cells, leading to a condition called hemolytic anemia. Because red blood cells carry oxygen, the body doesn't get as much as it needs. This can make people feel tired and may cause a higher heart rate
What causes aTTP/iTTP?
It may not be known why someone develops aTTP/iTTP, but the following could be triggers:
- Certain disorders or conditions, including cancer, HIV, lupus, infections, or pregnancy
- Surgery or certain other medical procedures
- Certain drugs or medications, including chemotherapy, hormone therapy, and estrogen-based medicines (such as oral contraceptives)
Blood flow without aTTP/iTTP
Blood clot formation in aTTP/iTTP
What are the signs and symptoms of aTTP/iTTP?
Everyone's experience with aTTP/iTTP is different. You may have had some of the following symptoms. These can be signs of aTTP/iTTP and could be a warning of having another aTTP/iTTP episode. This is called a relapse.
- Bleeding from the gums or nose
- Purple bruises (known as purpura) and/or red or purple dots (known as petechiae) on the skin
- Blood in urine
- Stomach pain
Blood clot-related symptoms
- Chest pain
- Headaches, confusion, and distorted vision
- Tiredness and jaundice (a yellowing of the skin and eyes)
The language of aTTP/iTTP
gnosis of aTTP/iTTP means you may hear new medical terms. Understanding these terms may help you feel more prepared for conversations with your doctor.
What do TTP and aTTP/iTTP stand for?
Thrombotic thrombocytopenic purpura (TTP): It is a rare disorder of the blood clotting system. It is considered to be a medical emergency requiring immediate attention in the hospital. TTP can be of 2 types: congenital (from birth) or acquired (development of the condition after birth usually due to some fault in the immune system).
Acquired/immune-mediated thrombotic thrombocytopenic purpura (aTTP/iTTP): Also known as Moschcowitz syndrome, it is a rare blood disorder that develops when the immune system stops ADAMTS13, a protein, from working properly. Without this protein, the body creates too many blood clots. These clots can limit or block the flow of oxygen-rich blood to the body's organs, such as the brain, heart, and kidneys. As a result, serious health problems can develop.
Acquired: Describes a condition that is developed later in life. It may be unknown why aTTP/iTTP has developed.
Immune-mediated: Means the cause of a condition is unknown, but it comes from an irregular immune response.
Thrombotic: Refers to the small blood clots that form inside blood vessels.
Thrombocytopenic: Means having a low platelet count.
Purpura: Red- or purple-colored spots on the skin that do not go away when pressure is applied. It may look like a bruise.
Glossary of aTTP/iTTP terms
ADAMTS13: An enzyme, or protein molecule, needed to prevent the body from making more blood clots than it needs.
Anemia (uh-NEEM-ee-uh): A drop in the number of red blood cells in the body. Red blood cells carry oxygen throughout the body.
Episode (or Event): An acute period when someone is affected by an illness.
Immune system: The body's natural defense system against a harmful organism that can make you sick.
Immunosuppressive therapy/Immunosuppressant: Treatment that helps decrease the activity of the immune system, which is overactive during an episode of aTTP/iTTP.
Intravenous (IV): Entering the body through a vein.
Jaundice: Yellowing of the skin and eyes.
Microthrombi: A blood clot located in a small blood vessel.
Microangiopathic Hemolytic Anemia (MAHA): Anemia caused by destruction of erythrocytes due to physical shearing as a result of passage through small vessels occluded by systemic microthrombi.
Moschcowitz syndrome: More commonly known as thrombotic thrombocytopenic purpura (TTP), it is a primary thrombotic microangiopathic disorder which is characterized by the classical "pentad" of fever, thrombocytopenia, microangiopathic hemolytic anemia (MAHA), renal failure, and neurological dysfunction.
Petechiae (puh-tEE-kee-ie): Small red or purple spots less than 1/8 of an inch in size on the skin.
Plasma exchange (PEX): A procedure that removes and replaces a person's blood plasma. This process helps clean the body by removing things it has too much of (such as immune cells) and adding things it has too little of (such as ADAMTS13 and platelets).
Platelets: A small cell found in the blood that is involved in clotting.
Recurrence: Any aTTP/iTTP episode that follows the first aTTP/iTTP episode.
Red blood cell: A cell that carries oxygen from the lungs to all parts of the body and then carries carbon dioxide back to the lungs to exhale out of the body.
Specialty pharmacy: A pharmacy that delivers medicines that are not available through a local pharmacy. It often provides services including:
- Shipping medicine directly to a patient's home
- Monthly check-ins with a patient to make sure they've completed required testing
- Being available to answer questions a patient or caregiver may have about receiving medicine
Subcutaneous (SC or subQ): Injected into the body under the skin.
von Willebrand factor (vWF) (vawn vil-uh-brahnt): One of the components in your blood that helps your platelets stick together.