Immune Thrombocytopenia (ITP)

  • What is immune thrombocytopenia?

Before going into immune thrombocytopenia, let us know about the basics of blood cells and bone marrow.

Bone marrow is the factory producing all the blood cells continuously. Our body needs continuous production of red cells, white cells and platelets which are constantly released into the blood stream from the bone marrow.

In the blood, these cells live for few days and lose their function and so they have to be constantly replenished.

Red cells carry oxygen throughout the body.

White cells fight against infection

Platelets prevent against minor bleeding from the blood vessels.

Red cells have Haemoglobin and the normal Hb in adult is around 14g/dl or 140g/L

White cells are around 3-10 x 109/L

Platelets are around 150-400 x 109/L

Normally platelets live for 5-10 days in the blood. In patients with immune thrombocytopenia (ITP), platelets are destroyed quickly, due to the antibodies in the blood. These antibodies for unknown reasons are produced against the platelets which cause destruction of platelets.

  • What happens if the platelets are destroyed rapidly?

The platelets are like the plumbers, which seal the holes formed in our blood vessels. Normally since the blood flows rapidly, numerous holes can be formed in the blood vessels on a continuing basis. They have to be sealed constantly to prevent minor or major bleeding from the blood vessels.  Even though the normal platelet count is around 150-400, any platelet count of more than 20-30 is quite safe in the sense, spontaneous bleeding is uncommon with that level.

Increased destruction of platelets can be compensated to a certain extent by the marrow by increased production. But, often the compensation fails, and so patients end up having very low platelet counts.

  • How are immune thrombocytopenias diagnosed?

It is very important to diagnose them properly.  As there is no single diagnostic criteria for diagnosis, these diseases are diagnosed by ruling out other causes of thrombocytopenia such as aplastic anemia, leukemia, myelodysplastic syndromes, marrow infiltration by lymphoma, microangiopathic diseases such as HUS, TTP etc. Hence a thorough examination of the blood film by a qualified person is necessary to rule out other disorders.

  • Will bone marrow be necessary in all the cases?

Bone marrows are not absolutely essential to diagnosed ITP, provided the blood smears are seen by experienced personnel. However, in refractory ITPs which do not respond to steroids, bone marrow may be of value to rule out other conditions such as myelodysplasis, before instituting further therapies.

  • How does patients with ITP present with?

They usually present with bleeding due to low platelets. The bleeding may be into the skin manifesting as purpura, or from the mucosa such as mouth or nose or sometimes internally.

  • What are the types of ITP?

The ITPs which respond to treatment and disappears within 6 months is called acute ITP. Sometimes, the ITP may persist for more than 6 months or keep recurring again and again, which is called chronic ITP. In adults around 60% of patients can become chronic ITP. In spite of this, most of the patients can be managed to keep the platelet count more than 20-30 with minimal proper immunosuppressive drugs. A platelet count of around 20-30 is sufficient to prevent spontaneous bleeds and they can lead a fairly normal life with that count.

  • Is platelet transfusion indicated in ITP?

Normally platelet transfusions are not indicated in ITP even with very low platelet counts of less than 10 x 109/L. Since platelets survive for only few hours in the blood in these patients, transfusions are of now value and so specific therapy has to be instituted soon. However in patients with severe ongoing mucosal bleeds unresponsive to local measures or in patients with internal bleed platelet transfusions are indicated to arrest the bleeding.

  • How is ITP treated then?

Since ITP is due to production of abnormal antibodies in the blood, which destroy the platelets, treatment is immune suppression. Most of the patients respond to immunosuppression with steroids. Some patients if they become chronic, may need to be treated with stronger immune suppression or removal of spleen (which is the site of destruction of platelets)

Many new drugs are available for treatment of ITP, some of them are very costly but you may not need them.

  • What is the natural course of immune thrombocytopenic purpura?

In some patients it will be an one time event. In many patients, they have to take some immunosuppressive drugs for a much longer time to keep the disease under control. (To find out which immunosuppressive durg best suits a patient may be a longer exercise sometimes). 

In few patients the disease remains quiescent for a long time, (for years) and gets exacerbated at times (during viral infections, pregnancy etc)

  • What precautions should I have to take?

Two things are important to remember.

As the disease may come back or exacerbated at any time, you should know to identify it much earlier. Any new pupura (red spots in skin) or mild bleeding from any site should alert you to check the blood counts.

Second thing, if you are on treatment esp immuno suppressive medications, during  any infections such as fever, cough, diarrohea etc, you have to get immediate and appropriate antibiotics. Contact your family Physcician immediately.

The most important thing to know is that in most people the aim of treatment is to attain a safe platelet count. So do not worry looking at the “PLATELET COUNT REPORTS” as the aim is to treat YOU and not your reports alone!!! You can lead a normal life for 100 years with a safe platelet count even if that is not “within the normal range”

Department of Hemato oncology,

Amended on Dec 14th, 2014 @VNCC, GKNM by Dr Suthanthira kannan,

Amended on 2nd Nov, 2016 @ Coimbatore Kidney centre by Dr Suthanthira Kannan

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