What is ITP?

In a nutshell, ITP (an abbreviation for "idiopathic thrombocytopenic purpura") is a disease that kills platelets. Platelets (thrombocytes) are blood cells, just like red cells and white cells, and they are responsible for blood clotting. If there are not enough platelets, cuts and bruises bleed longer and don't heal as well as they should. Platelets are also involved in storing serotonin, a brain neurotransmitter that is responsible for sleep/wake cycles, appetite and mood regulation. Thus, a decrease in platelet count may affect these functions.

Nobody knows why ITP develops. It is known, however, that ITP is an autoimmune disease, which means that an affected body starts attacking one or more of its organ systems. There are many autoimmune diseases, and ITP is just one of them. ITP triggers the immune system to mark platelets as foreign, and subsequently to destroy them in the spleen or, sometimes in the liver. ITP is generally not fatal; however, extreme cases may be life-threatening because of a risk of spontaneous hemorrhages, internal bleedings and hard-to-stop bleedings that might be caused by injuries. Also, people with ITP may suffer from depression and fatigue.

Who is Affected Most by ITP?

ITP occurs most often in women over 40 years of age. It may be acute, lasting for 6 months or less, or chronic, lasting for over a year. The acute type is more often seen in children and will cure itself in more than 80% of cases. The chronic type is more commonly seen in adults and it tends to get worse as the disease progresses.

What are the Symptons?

Occasionally, ITP patients suffer from bruising, nosebleeds, and bleeding gums; this is the characteristic pattern of bleeding in platelet disorders. Bleeding normally does not occur unless the platelet count is very low (below about 10,000 per mm3, compared to a normal range of 150,000–400,000 per mm3).

Subarachnoid and intracerebral hemorrhage are very serious possible complications of this disease. Fortunately, these are rare in patients who are being treated.

Treatment:

Mild ITP does not require treatment. When platelet counts fall under 10,000 per microliter, or under 50,000 when hemorrhage occurs (e.g. in the digestive tract or in a severe nosebleed) treatment is generally initiated with steroids. Intravenous immunoglobulin (IVIg) is used for life threatening cases. Later, so-called steroid-sparing agents (alternatively called DMARDs) may be used. When these strategies fail, splenectomy (removal of the spleen) is often undertaken, as platelets targeted for destruction will often meet their fate in the spleen. A relatively new strategy is treatment with anti-D, an agent used in mothers who have been sensitized to rhesus antigen by a Rh+ baby, but the patient must be Rh+. Immunosuppresants like mycophenolate mofetil and azathioprine are becoming more popular for their effectiveness. Rituximab has also been used with some success for some patients.

Extreme cases (very rare, especially rare in children) may require vincristine, a chemotherapy agent, to stop the immune system from destroying platelets.

Intravenous immunoglobulin, while sometimes effective although not all patients respond, is expensive and the improvement is temporary (generally lasting less than a month). However, in the case of a pre-splenectomy ITP patient with dangerously low platelet counts, and a poor response to other treatments, IVIg treatment can increase platelet counts, making the splenectomy operation less dangerous.

Platelet