Immune Thrombocytopenia – A quick summary   by Prof Adrian Newland

Immune Thrombocytopenia – A quick summary   

Professor Adrian Newland 

What it is ITP? – A disorder in which the body’s immune system destroys platelets in the blood. A normal platelet count is between 150- 400 (UK measurement). The platelet count in people with ITP may fall to levels where they are undetectable. Although this is rare. 

Immune thrombocytopenia (formerly known as idiopathic thrombocytopenic purpura) is a medical term for an autoimmune disorder (immune) causing a shortage of platelets (thrombocytopenia) and bruising (purpura). 

What causes ITP? – For most people there is no known cause, but for others, particularly children it can follow a simple viral infection such as a cold or sore throat and in this group the condition is often transient. In adults this association is much less strong and often no preceding cause can be found. It may follow a viral infection, vaccination or certain medications and is associated with other haematological conditions, although these are rare.  ITP can occur as a secondary condition to certain other autoimmune conditions such as Lupus (SLE) diabetes and thyroid disorders to name a few. There is an association with pregnancy and may arise while pregnant or in long-standing ITP may see worsening of the platelet count.  This would need close monitoring. 

As an autoimmune disease ITP sees disruption of the immune system in which the body mistakes the platelets as being foreign and destroys them often by the production of an antibody to one of the previously mentioned associated factors.  This is a simplistic description and your doctor can explain in more detail or through literature provided by the ITPSA. 

ITP that arises suddenly is known as acute ITP, if the platelet count remains low after 3 months it will be called persistent ITP, and if the platelet count has not returned to normal after 12 months it will be called chronic ITP. The severity of the condition is determined by the level of the platelet count and is considered severe if the count is less than 30, mild above this level and moderate between 50 and 100.adding the names severe or mild.  

What are the Symptoms? –  Some people with ITP, especially those with a count over 50, may have no symptoms at all, and their ITP only noticed during a routine blood test. A third of patients may be picked up in this way. Even people with very low counts, can sometimes have few symptoms and may only notice easy bruising. 

Common symptoms are:
petechiae (pinprick rash of blood spots)
bruising
nosebleeds
gum bleeds
black mouth (blood) blisters
fatigue
heavy periods 

Rare symptoms are:
blood in the eyes
bleeding from the ears
blood in the urine
bleeding from the gut
bleed into the brain 

How is ITP Diagnosed? –  ITP is usually diagnosed by a blood test showing that only the platelet count is low, and the platelets, red blood cells and white blood cells all look normal. A bone marrow biopsy may be taken at a later stage if the ITP continues, in which a small sample of bone marrow will be taken under local anaesthetic and examined under the microscope. Although this is now unusual. Additional blood tests may be taken at this time to exclude the known associated conditions and other rare clotting or immune diseases that can mimic ITP. If the bone marrow looks normal, with the usual or higher number of platelet parent cells (megakaryocytes) and other blood tests are normal then the doctor will diagnose ITP. 

Treatment options for ITP? – Treatment options for ITP are detailed on the ITP Support Association Website at www.itpsupport.org.uk .