Only nine or ten people in every 100,000 have ITP¹, a rare autoimmune disease affecting platelet production and characterised by fatigue, bruising and bleeding. Until recently, treatment options have tended to be ruled by compromise. But now, thanks to increased awareness of treatment options, a better life may be possible for people living with ITP.

What is ITP?

ITP stands for immune thrombocytopenia. The disease was previously known as idiopathic thrombocytopenic purpura, and this term may still be used. If the condition persists for more than a year, it is called chronic immune thrombocytopenia. Thrombocytopenia that is not caused by a previous disease is known as primary ITP. If the disease is caused by another condition affecting the immune system (such as HIV), it is referred to as secondary ITP.

The word thrombocytopenia simply means a deficiency of thrombocytes, or platelets. ITP is a rare autoimmune disease characterised by fatigue and increased risk of bleeding caused by not having enough platelets in the blood.

What are platelets?

Platelets are tiny, colourless cell fragments in the blood that form clots which stop or prevent bleeding. They’re called platelets because when viewed through a microscope in their inactive state they resemble plates. A platelet measures about 2 microns (about 0.002 millimetres) in diameter – that’s about one-quarter of the diameter of a red blood cell. Platelets are made in our bone marrow and those that are not used in clotting usually survive for seven to ten days before being destroyed naturally in the body.

Platelets help the body form clots, growing sticky tentacles and adhering to each other

When a blood vessel becomes damaged it sends out a signal. When the platelets receive that signal, they respond by travelling to the area and transforming into their active state, growing sticky tentacles that make the platelets adhere to each other and form a clot.

The blood needs a sufficient platelet count in order to clot normally. A normal platelet count ranges from 150,000 to 450,000 platelets per cubic millimetre of blood. A person who has a platelet count below 150,000 is said to have thrombocytopenia. People with severe ITP may have a platelet count below 10,000.²

How common is ITP?

The incidence of new diagnoses is around 3.3 for every 100,000 people each year.³ The prevalence of ITP among adults – how many people have the condition at any one time – is in the order of 9.5 cases per 100,000. Worldwide, this would lead to a total of more than 750,000 people affected by ITP. More women are affected than men.

How is ITP diagnosed?

ITP is identified by a diagnosis of exclusion. There is no single blood test that can prove whether a patient has ITP, so it has to be a process of eliminating other possible causes based on a patient’s history, on examinations, and on the results of initial tests. In diagnosing ITP, the healthcare provider will carry out blood tests to identify the underlying causes of low platelets. ITP is diagnosed if blood tests show that only the platelet count is low while the platelets, red blood cells and white blood cells all look normal.

In cases of persistent ITP, a bone marrow biopsy may be recommended to rule out other causes for a reduced platelet count. A small sample of bone marrow is taken under local anaesthetic and examined under the microscope. If the bone marrow is free from abnormalities and other blood tests are normal, then chronic ITP will be diagnosed.

What causes ITP?

Primary ITP is an autoimmune disease: the immune system mistakes the body’s platelets as being foreign and destroys them.¹ The condition may be triggered by:

• Allergic reaction to medications
• Viral infections
• Pregnancy
• Immune disorders such as rheumatoid arthritis and lupus.

ITP usually develops gradually and often without a clear cause. When the condition lasts more than a year it is called chronic ITP.

ITP can also arise as a result of another illness, in which case it is called secondary ITP.

Living with ITP

Immune thrombocytopenia has a substantial, multifaceted impact on patients' health-related quality of life (HRQoL).⁸

The impact of ITP will vary from person to person and the reasons for symptoms may also differ.

Fatigue is one of the main symptoms of ITP reported by patients. Various studies show that at least half of people living with ITP experience fatigue that can often interfere with everyday life.⁸

The fatigue experienced by people with autoimmune diseases such as ITP is different from the normal, temporary fatigue we all feel after a taxing activity such as concentrating for a long time or vigorous exercise, or after a poor night’s sleep. That kind of fatigue goes away with rest. But ITP-related fatigue can be debilitating and can interfere with people’s ability to engage in everyday activities. In some cases when the platelet count is low it goes beyond a feeling of tiredness to brain fog and an inability to carry out simple tasks like recalling a two-digit number after ten seconds.⁹ ITP patients have described how they are obliged to take time out from their work or studies to sleep during the day.¹⁰

People living with ITP may worry about how bleeding could affect their work and social activities. For most people, the impact of ITP on their quality of life seems to reduce after the first year.¹¹ This may be partly because they learn coping strategies to adapt and live with the condition, and partly because they respond well to treatment.

Many of those living with ITP report impacts on their emotional wellbeing, with emotional and mental stress and anxiety, and a greater risk of depression.^12, 13

What treatments are available?

ITP affects different people in different ways and a range of treatments is available. People with mild cases may need nothing more than regular monitoring and frequent platelet checks. However, adults who develop chronic ITP will in many cases eventually need treatment.^{14, 15}

There is no cure for ITP but there are treatments that can raise the platelet count and thereby counteract the symptoms and help people to live with the disease.

Treatments include steroids as an initial short-term measure, immunoglobulin, drugs to reduce the immune system response that is causing the platelets to be destroyed, and TPO-RAs (thrombopoietin-receptor agonists), which can lift the platelet count by boosting platelet production in the bone marrow.

For patients who continue to have severe symptoms despite treatments, their doctor may suggest a splenectomy (surgery to remove the spleen).

How treatments affect people's lives

For many patients, problems associated with their treatment can be an important aspect of living with ITP. Some people don’t like needles, for example, while some ITP treatments are administered by subcutaneous or intravenous injection. Some treatments carry a risk of hepatotoxicity – meaning that there is a danger of damage to the patient’s liver. One TPO-RA treatment, although oral and relatively easy to administer, requires food-type restrictions. Today, with the choices available, ITP patients can discuss their concerns with their healthcare providers and ask them for alternatives that reduce the need for compromise in their lifestyles.

NP-20055. January 2022.