WHAT IS THROMBOTIC THROMBOCYTOPENIC PURPURA (TTP)?
TTP is an ultra-rare blood disorder which is more common among women than men. While it can affect people of all ages, the average age of diagnosis is 40 years.
In TTP, blood clots form in small blood vessels throughout the body. These clots can limit or block the flow of oxygen-rich blood to the various body organs, such as the brain, kidneys and the heart, and this could result in serious health issues.
TTP is a life-long condition and many patients experience further episodes (known as relapses) post diagnosis. These episodes are serious and could be life-threatening.
TTP describes three of the main features of the condition:
- Thrombotic – this refers to the blood clots that form
- Thrombocytopenic – this means that the blood has a lower than normal number of platelets, and
- Purpura – this refers to the purple bruises caused by bleeding under the skin
Actually, a lack of activity in the ADAMTS13 enzyme (a type of protein in the blood) causes TTP. The ADAMTS13 gene controls the enzyme that is involved in blood clotting. This enzyme breaks up a large protein called von Willebrand Factor that clumps together with platelets to form blood clots.
WHAT ARE THE TYPES OF TTP?
There are two main types of TTP – Inherited and Acquired.
Inherited TTP: This means that the condition is passed from the parents to the children through genes and this type of TTP mainly affects newborns and children. In Inherited TTP, the ADAMTS13 gene is faulty which results in the enzyme activity either lacking or changing.
Acquired TTP: This is more common and occurs mostly in adults, but it can also affect children. In Acquired TTP, the ADAMTS13 gene isn’t faulty and instead, the body makes antibodies or proteins that block the activity of the enzyme.
WHAT CAUSES TTP?
Doctors and scientists are not clear as to what triggers Inherited and Acquired TTP, but there are some factors that play a role:
- Some diseases and conditions, such as pregnancy, cancer, HIV, lupus and infections
- Some medical procedures, such as surgery and stem cell transplant
- Some medicines, such as chemotherapy, hormone therapy and estrogens
- Quinine – a substance often found in tonic water and nutritional health products.
WHAT ARE THE SIGNS AND SYMPTOMS OF TTP?
Blood clots, a low platelet count, and damaged red blood cells cause the signs and symptoms of TTP:
- Purplish bruises on the skin known as purpura and are caused by bleeding under the skin
- Pinpoint-sized red or purple dots on the skin called petichiae. Often found in groups and may look like a rash.
- Paleness or jaundice
- Fatigue
- Fever
- Fast heart rate or shortness of breath
- Headache, speech changes, confusion, coma, stroke or seizure
- Low amount of urine
HOW IS TTP DIAGNOSED?
The diagnosis of TTP is done based on the patient’s medical history, a physical examination and some tests. And once, the doctor suspects or diagnoses TTP, a Haematologist gets involved. A Haematologist is a doctor who specializes in diagnosing and treating blood disorders.
The various diagnostic tests that that doctor might ask for are:
- Complete Blood Count (CBC) - to measure the number of red blood cells, white blood cells, and platelets in the blood. A patient with TTP will have a lower than normal number of red blood cells and platelets.
- Blood Smear - A sample of blood is drawn from a vein, usually in the arm and is put on a glass slide. A microscope is then used to examine the red blood cells – a patient with TTP will have torn and broken red blood cells.
- Platelet Count - This test counts the number of platelets in the blood smear. Patients with TTP have a lower than normal platelet count.
- Bilirubin Test - When red blood cells die, they release a protein called haemoglobin into the bloodstream. The haemoglobin is then broken down into a compound called Bilirubin. The level of Bilirubin in the blood is checked, and if a patient has TTP, the Bilirubin level will be high as the body is breaking down red blood cells faster than normal.
- Kidney Function Tests and Urine Tests - These tests show whether your kidneys are working well. If you have TTP, your urine may contain protein or blood cells. And your blood creatinine level may be high (creatinine is a blood product that’s normally removed by the kidneys).
- ADAMTS13 Assay - As we’ve read above, a lack of activity in the ADAMTS13 enzyme causes TTP. In this test, a sample of blood is drawn from a vein in the arm and the sample is sent to a special lab to test for the enzyme’s activity.
HOWIS TTP TREATED?
TTP is a life-threatening disorder, it can be fatal or can cause lasting damage (such as brain damage, or a stroke) if not treated right way. TTP occurs suddenly in most cases and may last for days or weeks or sometimes months. In many cases, relapses (also known as flareups) occur.