ITP (primary immune thrombocytopenia) > Health and Wellness.

It primary immune thrombocytopenia (ITP) is a disease of autoimmune origin in which there is a low number of platelets (which is known as thrombocytopenia or thrombocytopenia) due to increased platelet destruction and, to a lesser extent, to a defect in its production. We say it has an auntoinmune origin because it's own immune system of the patient who produces antibodies that destroy platelets in the blood and prevent its production in the bone marrow. Having a low number of platelets, patients have more risk of bleeding and possible bleeding. It can affect both children and adults.
Today the term idiopathic thrombocytopenic purpura or immune is unused is called primary immune thrombocytopenia (ITP in Spanish and ITP in English) or secondary.
There is no data on the prevalence or incidence of exact of ITP in Spain, although some experts estimate that 5,000 cases it round. Other parts of the world, such as United States, estimates that the incidence of ITP in adults round six cases per 100,000 inhabitants, while in the United Kingdom the prevalence in adults stands at 1.6 per 100,000. What is clear is that the incidence of this disease is increasing in recent years.

Causes of primary immune thrombocytopenia (ITP)

Patients with PTI create autoantibodies that are aimed to the membrane of platelets and megakaryocytes (the platelets in the bone marrow precursor cells), which occurs a destruction of platelets at the spleen and a decrease in the production of platelets at the spinal cord level.
In the majority of cases, the cause that triggers the production of autoantibodies against platelet is unknown, especially in adults. However, in children, in many cases, the PTI occurs after viral infection or immunization using live attenuated virus.
There are other so-called secondary autoimmune thrombocytopenia where the cause is known, for example, associated with common variable immunodeficiency, autoimmune diseases, pregnancy, infection by the hepatitis C virus or infection by HIV. Autoimmune thrombocytopenia secondary to drugs is also frequent.

Symptoms of ITP

The way in which ITP, is presented as well as their characteristic signs and the clinical development of the disease are highly variable, which complicates much diagnosis, the choice of the adequate treatment and follow-up of patients, who clearly affected their quality of life.
Patients with primary immune thrombocytopenia they may not have symptoms or they may have different gravity hemorrhagic manifestations, which depends mainly on the number of platelets.
Characteristic is the presence of petechiae, which are small eruptions on the skin or in the mucous membranes, such as red-purplish spots, caused by the output of red blood cells through the wall of the blood vessels. The petechiae do not disappear or are bleached by compressing them. This characteristic distinguishes them from other skin lesions papular which can be similar (such as those caused by bites of insects, allergies, infections...) that duty is a simple vasodilation are bleached by compressing them with your finger.
When the petechiae are greater than 3 mm are called purple, hence comes the name of this disease. Greater than 1-2 cm purpuric lesions are referred to as bruising, which is popularly known as hematoma or bruising.
The petechiae, purpura, or ecchymosis appear with more prevalent in the lower third of the leg, to be part of the body where the blood vessels are under greater pressure. They can also appear after small injuries.
In addition, there may be bleeding by the mucous membranes, such as bleeding through the nose (epistaxis), bleeding from the gums or vaginal bleeding. More uncommon form it produced more severe bleeding as the gastrointestinal, joints or brain.

Diagnosis of ITP

The diagnosis of primary PTI is defined by thrombocytopenia (< 100,000 platelets/µl of blood) in the absence of other associated causes. There is no specific test for its diagnosis, therefore, it will have to reach him after having excluded other causes of thrombocytopenia, as infections (hepatitis C, HIV...), use of drugs, other autoimmune diseases, etc. For this reason, the clinical history along with laboratory parameters are essential to make the diagnosis of ITP.
The figures in the blood red blood cells (erythrocytes) and white blood cells (leukocytes) are usually normal. If you notice the blood under a microscope, testing is called peripheral blood smear, larger than normal but a few platelets are. Studies evaluating the blood clotting do not often show abnormalities.
Sometimes performed a bone marrow biopsy, which is the body where blood, occurs to rule out other diseases that could explain the decrease in platelets. It is usually done in the case of PTI's atypical presentation, as in people older than 40 years, when there are associated alterations of white or red blood cells, or when there is a good response to treatment.
Also look for the presence of blood antiplatelet antibodiescan be. This test is not very sensitive (can be negative in many cases from PTI), but is quite specific (if it is positive, tends to indicate that we we have an PTI).

Treatment of ITP

The therapeutic management of ITP must taken into account not only the platelet number, but also the hemorrhagic manifestations and associated diseases of the patient.
Treatment of PTI aims get one adequate platelet number (generally > 30,000 platelets/µl) to prevent bleeds with the least number of side effects of the medications used. The risk of bleeding should be individualized according to associated diseases, age of the patient (there is increased risk of bleeding in children and the elderly) or in those who must undergo major surgery, so the platelet number that we want to reach with treatment may vary according to circumstances.
On the other hand, the treatment is unnecessary in many patients who have PTI. For example, in general, patients with mild thrombocytopenia having no hemorrhagic manifestations or serious illnesses do not treat. However, there are certain situations in which these patients should receive treatment, such as major surgical interventions or pregnancy.

What is the treatment of ITP

The treatment of primary immune thrombocytopenia consists of:


Currently recommended administration of prednisone at doses of 1 mg per kilo of weight and day for 21 days, then go down the dose gradually. There are different treatment regimens with other corticosteroids such as dexamethasone or methylprednisolone. Around 80% of patients respond to corticosteroids. The side effects of steroids used in the long term are, for example, diabetes mellitus, cataracts, weight gain, high blood pressure or osteoporosis.

Gamma globulins

The intravenous gamma globulin may be used, associated or not to corticosteroids, if you require a rapid increase (urgent cases) in the number of platelets. Globulins are antibodies that inhibit harmful antibodies that the body is producing and which are causing the destruction of platelets. More than 80% of the cases respond positively, but its effect is transient.

Splenectomy (removal of the spleen)

In case of failure to Corticoid treatment, well because there have been multiple relapses of the disease or because the patient does not respond, the next step is to start a second-line treatment. Splenectomy is considered a second-line option, although there are other options with drugs that will be detailed in subsequent paragraphs. To indicate a Splenectomy must be evaluated, mainly, the age of the patient (in children is usually not perform), lifestyle, time since diagnosis (recommended wait between 6-12 months due to spontaneous healing), the number of platelets that has the patient, hemorrhagic manifestations and therapeutic preferences. Between 75-85% of patients achieve a quick response after the intervention, being durable responses in two thirds of cases. The mortality of Splenectomy is 0 2 - 1%. The risk of bacterial sepsis postesplenectomia is 1%, so it is recommended vaccination against meningococcus, Pneumococcus and Haemophilus influenzae B before the intervention.

The thrombopoietin receptor agonists

(Romiplostim and eltrombopag)

These drugs have been recently approved for patients who have not responded to Splenectomy or who cannot make it by contraindication or impossibility of the surgery. These drugs have had a big scientific development into human clinical trials and its mechanism of action is totally different from the of the classic drug of ITP, since they increase platelet production by stimulating the thrombopoietin (TPO) receptor without modifying the immune response of the patient. They present different routes of Administration: eltrombopag is administered orally and the romiplostin subcutaneously. They have an efficiency of about 80% and they must be administered chronically. Maximum responses attained with both drugs are very fast, around two weeks, and are durable. Described most often after their side effects are mild, such as headache, although there are other less frequent that the doctor must control.

Other drugs

For patients with PTI refractory to Splenectomy and trombopoyeticos agents, treatment options are many, but the response rate and duration are very variable. There are no controlled studies that have evaluated or relative to its effectiveness. Treatments considered in these cases are: agents that suppress/immunomodulators (azathioprine, Cyclosporine, danazol, Dapsone, Mycophenolate), rituximab (monoclonal antibody that inhibits the type of white blood cell that produces harmful antibodies for the patient), chemotherapy alone or in combination, or transplantation of hematopoietic progenitors.

Platelets trasfusion

It only occurs if there is a hemorrhage with vital irrigation, because platelets are destroyed quickly and its beneficial effect is very brief.

Tips for patients with PTI

In addition to the treatments, there are some tips you should follow patients with PTI:
  • They should avoid activities that expose them to trauma, such as for example the physical contact sports.
  • Refrain from taking aspirin and other anti-inflammatory drugs, which can affect the function of platelets.
  • They should not receive intramuscular medications, because there is the risk of bruising inside the muscle.
  • They have to be evaluated and followed by a physician hematologist.
Published for educational purposes
Health and Wellness

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