ITP and Sjögren’s Disease: What’s the Link?

Having more than one autoimmune disease — like immune thrombocytopenia (ITP) and Sjögren’s disease — can feel overwhelming, especially if you’re newly diagnosed. But you’re not alone. Having more than one autoimmune condition is more common than you might realize.

In fact, nearly 25 percent of people with one autoimmune condition will develop another one at some point in their lives. If this is the case for you, you may be wondering why this happens. Here’s what you need to know about the connection between ITP and Sjögren’s.

What Does Polyautoimmunity Mean?

Immune thrombocytopenia (ITP) and Sjögren’s disease sometimes occur together in the same person. When they do, or when any two autoimmune disorders occur together, this is called polyautoimmunity.

Polyautoimmunity may result from a mix of genetic, immune, and environmental factors. ITP has been reported alongside many other autoimmune diseases, but the exact number and frequency are not clear.

Some small studies have found that a few people with ITP have more than one other autoimmune disease. In one study group, combinations involving Hashimoto thyroiditis, lupus, and Sjögren’s were reported. These findings may not apply to everyone with ITP.

What’s the Link Between ITP and Sjögren’s?

ITP and Sjögren’s disease can be diagnosed in any order. One condition may be diagnosed before the other, or both may be found around the same time. But this does not prove that either disease causes the other.

In one study of 164 people who had both conditions, nearly 35 percent were diagnosed with ITP and Sjögren’s disease at the same time. About 37 percent were diagnosed with ITP first. These results came from one selected group and may not reflect everyone with both conditions.

The researchers also noted that those with severe bleeding were most often diagnosed with ITP before they were diagnosed with Sjögren’s disease.

Why Can Sjögren’s and ITP Occur Together?

Scientists are still studying how Sjögren’s and ITP are connected and what happens inside your body when you have both conditions. Most of what they’ve discovered is still in the early stages, but they’re making progress. Early research suggests that platelets may be removed faster and that the bone marrow may produce new platelets more slowly when both conditions occur together.

Researchers are still looking into which immune cells and proteins may be involved. They are studying possible roles for a protein called TLR7, overactive B cells, antibodies that target platelets, and macrophages. These are possible explanations and have not been proven to occur in every person.

Ultimately, more research is needed to fully understand how the two conditions interact and what to expect when you have both.

How Do Symptoms Compare When You Have Both Conditions?

Because Sjögren’s disease and ITP are two distinct autoimmune conditions, their symptoms are different. But knowing which symptoms each disorder causes can be useful. This can help you identify when you’re experiencing something new or you need medical care.

For instance, if you’ve been diagnosed with Sjögren’s and start noticing ITP symptoms, you might want to ask your healthcare provider to run some tests or schedule an appointment with a hematologist. Here’s an overview of the distinct symptoms of each condition.

What’s the Long-Term Outlook if You Have Both Conditions?

Some studies of selected groups of people with Sjögren’s have reported ITP in about 10 to 20 percent of people. However, this range shouldn’t be used to predict one person’s risk. Some studies suggest that ITP may be found later in the course of Sjögren’s, but more research is needed.

If that happens, having low platelets in addition to Sjögren’s symptoms creates some unique risks. One study of hospitalized people with Sjögren’s found that low platelet counts were linked to a higher risk of death during that hospital stay. These patients were already sick enough to need hospital care, so this finding does not apply to everyone with Sjögren’s and low platelets.

Some small studies have reported more bleeding or active disease in people with both conditions. However, outcomes vary, and larger studies are needed.

Treatment depends on platelet count, bleeding, symptoms, and response to earlier treatment. Options for treating ITP may include corticosteroids, intravenous immunoglobulin, thrombopoietin receptor agonists, rituximab, fostamatinib, splenectomy, and rilzabrutinib for some adults with persistent or chronic ITP who did not respond well enough to earlier treatment.

Further Research

Researchers are looking at ways to identify biomarkers that can help predict how ITP and Sjögren’s will progress when they occur together. These biomarkers could help doctors avoid unnecessary treatments and choose the best therapy options.

This type of information could also potentially lower the risk of infections and medication side effects and improve the chances of early remission. This, in turn, could lead to better long-term outcomes.

One possible biomarker being studied is the number and appearance of megakaryocytes in a bone marrow sample. Some early studies suggest that the number and appearance of megakaryocytes, the bone marrow cells that make platelets, may be linked to treatment response. However, bone marrow testing is not routinely used to predict treatment response in people with typical ITP, and these findings are still investigational.

Larger studies are needed to determine whether these biomarkers are reliable and useful in medical care. Additional research may also help improve treatment choices.