Immune thrombocytopenia and lupus are both autoimmune conditions, or conditions in which the immune system attacks the body’s own tissues and organs. When someone with lupus develops ITP, it’s called secondary ITP. Secondary ITP is ITP that is the result of another health condition.
It’s unclear whether lupus can directly cause ITP, but people with lupus have an increased risk of developing ITP. Between 7 percent and 30 percent of people with systemic lupus erythematosus (the most common type of lupus) develop secondary ITP.
Lupus and ITP are both complex autoimmune disorders. Doctors and researchers are still working to understand what causes them and why someone may develop both conditions. This article will discuss the connection between lupus and ITP, including their symptoms, how they’re diagnosed, and how they’re treated.
Antibodies are normally made by our immune systems to help our bodies fight infections from bacteria and viruses. In autoimmune diseases, the immune system makes antibodies that target your body’s own cells and tissues as invaders that need to be destroyed. The antibodies that attack the body itself are known as autoantibodies.
ITP occurs when autoantibodies tag and destroy your platelets. Platelets are cells that help your blood clot. When platelet counts are low, you’re at an increased risk of excessive bleeding.
Platelets are made by specialized cells in your bone marrow (the spongy tissue inside your bones) known as megakaryocytes. When platelets are destroyed faster than they can be replaced, the platelet count decreases. Some people with ITP also have autoantibodies that tag megakaryocytes for destruction.
In lupus, autoantibodies attack tissue and cells in different parts of the body, like the joints, skin, heart, brain, and kidneys. Sometimes, the autoantibodies target the nucleus, the central part of cells.
While doctors and researchers are still learning about why lupus is associated with an increased risk of ITP, they believe it’s due to a combination of genetic factors and the presence of certain autoantibodies. For example, people with lupus typically have autoantibodies that target platelets — however, these antibodies are not always the same ones seen in ITP.
Symptoms of lupus can vary from person to person. They may depend on what organs and areas of the body are targeted by autoantibodies. Researchers have suggested that, in some cases, ITP can be an early sign of lupus.
Common symptoms of lupus include:
Since these symptoms are nonspecific and can be signs of other medical conditions, diagnosing lupus can be difficult.
Symptoms of ITP are typically the same for people with or without lupus. Often, people won’t have any ITP symptoms, and low platelet counts won’t be discovered until there is a blood test for another condition or someone has a bleeding event.
Noticeable symptoms of ITP may include:
Whether or not you have lupus, tell your doctor if you experience any of these symptoms. Giving your doctor an accurate picture of all of your symptoms will help them determine what blood tests and exams to perform for the most accurate diagnosis.
Lupus can be difficult to diagnose because it looks similar to other autoimmune diseases. It can’t be diagnosed with a single blood test or biopsy. Instead, doctors use different tests to help rule out other conditions and make a final diagnosis. These include:
A CBC test is also used to determine whether you have ITP. Doctors will use this test to check if your platelet count is low. If your white blood cell or red blood cell counts are higher than normal, this may point to an infection or a different condition.
Your doctor may also take a sample for a blood smear. In this test, a drop of blood is smeared on a piece of glass and stained with chemicals to mark different blood cells. A specialist then looks at the smear under a microscope to check if you have fewer platelets than normal or if they’re bigger or smaller than they should be.
Since you can have lupus and ITP at the same time, when diagnosing ITP, your doctor may also test you for comorbid lupus. Tests for lupus in someone with ITP include testing for the antinuclear antibody (ANA), as well as several others. Presence of certain antibodies shows disease activity in the immune system and can lead to a lupus diagnosis.
Since lupus and ITP both affect the immune system, most of their treatments work in the same way — aiming to reduce immune system activity and calm inflammation. Treatment plans will depend on your specific symptoms. For example, if you have ITP with no symptoms, you may only need follow-up monitoring and blood tests from your doctor.
For people with lupus and ITP who do have symptoms, there are several treatment options. In cases where platelet counts are extremely low, the first-line treatment is corticosteroids. These medications help decrease inflammation and prevent the immune system from attacking platelets. Two corticosteroids commonly prescribed for ITP are prednisone and dexamethasone. Corticosteroids are usually only prescribed for short periods, because they have side effects when used long term.
Another treatment for incidences of extremely low platelet counts in people with ITP and lupus is intravenous immunoglobulin (IVIG). This treatment uses concentrated antibodies from donors to stop the immune system from targeting platelets. It helps to raise platelet counts within a few days, and it has been effective in treating ITP in people with lupus.
The biologic drug rituximab (Rituxan) is also used to treat refractory cases of lupus and ITP — cases that have not been helped by the initial treatment. Rituximab blocks B cells, which are responsible for making autoantibodies. In some case studies, rituximab has been shown to help treat both conditions in children and adults.
Other treatment options for people who have both lupus and ITP may include:
If you have lupus and ITP, work with your doctor to determine the best treatment plan for you. You may want to seek specialist care from experts in both hematology (study of blood and blood disorders) and rheumatology (study of diseases in the bones, muscles, and joints). While there’s not yet a cure for ITP or lupus, treatments can help relieve pain and other symptoms and improve your quality of life.
On myITPcenter, the site for people with immune thrombocytopenia and their loved ones, people come together to gain a new understanding of ITP and share their stories with others who understand life with ITP.
Are you living with both lupus and ITP? What helps you manage both conditions? Share your experience in the comments below.
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