Immune Thrombocytopenia

Known as ITP, Immune Thrombocytopenia or Idiopathic Thrombocytopenia Purpura, and is an autoimmune disease.

An autoimmune disease is a condition in which your immune system attacks cells in your own body, and in the case of ITP, your immune system attacks your platelets in the blood and megakaryocytes in the bone marrow resulting in low platelet counts.

A patient with ITP will typically have a platelet count of 0 (severe ITP) to 100 (mild ITP) where a healthy platelet count will range between 150 – 450 x 109/L (or 150,000 – 450,000).

What are platelets?

Platelets are produced in the bone marrow along with red and white blood cells. When released into the blood the cells circulate within the blood and bind together when they receive a signal indicating that there are damaged blood vessels. For example, when you get a cut the platelets bind to the injured site resulting in the first stages of a clot and then the bleeding stops.

What else should I know?

Patients with ITP can suffer from a vast range of symptoms. Some may only be aware of a low platelet count by having blood tests, while others can experience bleeding, bruising, fatigue and low mood, among other symptoms. To understand ITP more and how it can impact everyday activities head to our Living with ITP page

Symptoms of ITP

Patients with ITP can suffer from a vast range of symptoms. Some experiencing only a handful, while other patients will experience a majority. The most common symptoms include Spontaneous bleeding and bruising, Petechiae (skin rash of small red dots, most prominent on the lower legs, but can be found anywhere on the skin), Bleeding gums &/or Blood blisters in the mouth, Heavy or abnormal menstruation, Nose bleeds, Internal bleeding, Fatigue and Low mood (depression).

Types of ITP

There are three stages of ITP patients.

Newly diagnosed ITP – within three months of initial diagnosis. In children this commonly follows a viral infection and in the majority of cases, full recovery is expected. In adults, there is often no clear event leading to ITP and the majority of cases will go on to have longer term problems (not all needing treatment).

Persistent ITP – between three months and one year from initial diagnosis. This includes cases were the platelet count has fallen after initial treatment has been tapered and cases where the platelet count has not recovered to above 100.

Chronic ITP – more than 12 months. Cases of persistent ITP are found more commonly in adults. The platelet count is anywhere below 100. Some cases with higher platelet counts might not need treatment, but cases with severe ITP (platelet count below 30 or with bleeding) will need treatment. Often if the platelet count above 30, no treatment is needed unless surgery is required or blood thinning treatment is needed (for a stroke, heart attack or blood clot).


Is a process of elimination

There is no single test currently available to determine that a person has ITP as there are many causes for a low platelet count. The most important part of the diagnosis is a careful history taken by your doctor or specialist (haematologist), particularly focusing on any past infections, prescribed and non-prescribed medications. Currently, patients who are diagnosed with ITP go through a variety of tests to determine the diagnosis of ITP. These may include:

  • A full blood count – This test includes a patient’s platelet count, but can also identify any other potential issues.
  • Basic chemistry tests checking kidney and liver function and “LDH”, which if raised can suggest an alternative cause for the low platelets
  • Viral and auto-immune screening process (an ANA test) – An ANA test (Antinuclear Antibody) test is positive when you have symptoms that suggest a broader autoimmune disorder. Further tests may then be required.
  • HIV and hepatitis tests as a type of ITP are much more common in people with these viruses and treatment will be different.
  • Some patients will then undergo a bone marrow biopsy – As platelets are formed in the bone marrow. Your doctor may wish to perform a biopsy to check the health of your bone marrow. This is not always required, but is commonly needed in older (>60 years) people.