TMA - What Does it Mean...

In the past few years the term "TMA" has surfaced and has been used when describing/referencing TTP. As a result, some Answering TTP Foundation community members have asked us; what do the letters stand for and can you provide us with a less technical explanation so that it is easy to understand.

Ergo this blog post!

TMA stands for Thrombotic Microangiopathy and the meaning behind those words further helps to describe what TMA actually means:

Thrombotic = blood clots

Microangiopathy = small blood vessel problems

The term TMA is an "umbrella" term that describes the following conditions:

• Congenital and idiopathic Thrombotic Thrombocytopenic Purpura (TTP)
• Secondary TTP
• Shiga toxin-producing E Colihemolytic uremic syndrome (STEC-HUS)
• Atypical hemolytic uremic syndrome (aHUS)
• Disseminated intravascular coagulation (DIC)
• Malignant Hypertension
• Scleroderma Renal Crisis (SRC)
• HELLP- Syndrome of Hemolysis, Elevated Liver Enzymes, and Low Platelets that may rarely occur in pregnancy

These disorders are so similar in presentation that it makes it difficult for doctors to differentiate between them and some patients are initially misdiagnosed.

What do TMA disorders have in common?

TMA patients present with the following symptoms:

SYMPTOM	REASON SYMPTOM OCCURS
Fatigue, Dizziness, Shortness of breath	Low red blood cell count
Bruises, Gum/nose bleeds, Minor cuts bleed a lot	Low platelet count
Confusion, Sleepiness, Seizures	Damage to blood vessels in the brain
Decreased urine, Swollen legs, High blood pressure	Damage to blood vessels in the kidney
Fever (more common with TTP)

Patients suffering from any of these "TMA" disorders have a low platelet count due to the clumping of platelets in small blood vessels. This can cause injury to organs such as the kidneys (most commonly effected organ among TMAs), heart, brain, pancreas, and liver.

TMA also causes red blood cells to burst and form schistocytes (deformed red blood cells), which can be seen in the blood smear (a test used to look for abnormalities within the blood). Normal blood has completely round red blood cells and plenty of tiny platelets. When you suffer from TMA your blood will have deformed red blood cells (called schistocytes) and no platelets.

TMA registries have been created worldwide to capture data on patients that present with one of the TMA disorders. Such registries will be beneficial in studying these conditions and maybe providing answers about what causes them, if they have similar treatment methods and if there is a cure.

Here are some links to articles that further describe TMA disorders:

• Thrombotic Microangiopathy and Associated Renal Disorders
• Thrombotic Microangiopathies
• Thrombotic Microangiopathy
• Thrombotic Microangiopathy, Hemolytic Uremic Syndrome, and Thrombotic Thrombocytopenic Purpura.

Please contact us if you require more information by sending an email to Contact@AnsweringTTP.org!