5 things you didn't know about B cells and autoimmune disease

Key takeaways

• Sjögren's disease is a serious, systemic autoimmune disease thought to be driven by B-cell dysregulation—and that underlying disease activity is constant, even when symptoms feel like they are easing up.^1-3
• B cells normally fight infection, but in Sjögren's and other autoimmune diseases, they can become hyperactive and mistakenly attack the body's own tissues.^2,4
• Sjögren's isn't the only autoimmune disease where B-cell activity can go wrong.^5,6
• Understanding what's happening inside your body is the first step toward more informed conversations with your doctor.
• Novartis has made immunology one of its key focuses of research, pursuing a deeper understanding of the biology behind B-cell driven diseases to work toward new treatment options.

If you or someone you love is living with Sjögren's disease, you probably know the most common symptoms, including dry eyes, dry mouth, fatigue, and joint pain.^1,7 But you may not know what's actually driving the disease.

Sjögren's disease is a systemic autoimmune disease that can be serious and progressive, meaning it can affect the entire body rather than just one area.^1,8-10 In autoimmune diseases, the immune system mistakenly attacks the body's own tissues, which can cause ongoing inflammation and damage.² In Sjögren's disease, B cells—an important type of immune cell—are believed to be a central driver behind many of the disease's seemingly unrelated symptoms.²

Learn more about Sjögren's disease

1. B cells are supposed to protect you—until they don't

B cells are a type of white blood cell that defend the body by producing antibodies—proteins that identify and neutralize threats like bacteria and viruses.⁴ In autoimmune diseases, these defender cells can turn hyperactive and mistakenly attack the body's own tissues.^5,6 B cells start misbehaving when genetic or environmental factors trigger an overproduction of a chemical signal called BAFF (B-cell activating factor).² Excess BAFF then plays a key role in amplifying the abnormal immune response.²

That's what happens in Sjögren's disease and other B-cell driven diseases, like lupus. Instead of only targeting foreign invaders, rogue B cells produce antibodies that attack the body itself, triggering chronic inflammation that can damage tissue over time and cause the common symptoms you're likely familiar with, as well as more serious complications affecting the lungs, nerves, and other organs.^2,11

This process is key to understanding the disease, including why its symptoms are so varied, why it's so hard to diagnose, and why managing each symptom alone may not be enough.

READ: Why Women Are Disproportionately Impacted by Autoimmune Disease

2. Sjögren's disease symptoms trace back to B cells

In Sjögren's disease, overactive B cells can drive inflammation across glands, joints, nerves, and organs—producing symptoms that can seem entirely unrelated.^2,11,12 Dry eyes. Cavities that keep coming back. Joint pain. Numbness in the hands or feet.¹³ These may seem like separate problems, but they may share a single root cause.

That's why the disease looks different in every person and why it's so hard to diagnose. Sjögren's disease can mimic conditions like menopause, lupus, or fibromyalgia, and a person may see several doctors before anyone connects the dots.¹² The symptoms don't look like one disease until you understand the biology linking them.

READ: One Woman’s Burden of Living with Sjögren's Disease

3. Your B cells don't take days off

Sjögren's symptoms can ebb and flow, with some days feeling more manageable than others.¹⁴ But in Sjögren's disease, it’s important to understand that B-cell dysregulation is constant, even when the symptoms aren’t. The immune activity driving the disease doesn't always mimic how a person feels.^2,3

The outside of the car can look fine while the frame corrodes underneath, whether you notice it or not. In the same way, B cells continue driving inflammation even on the days a person feels well.

Think of rust on a car. The outside of the car can look fine while the frame corrodes underneath, whether you notice it or not. In the same way, B cells continue driving inflammation even on the days a person feels well.^2,3 A “good day” doesn't necessarily mean the disease has slowed down.

4. Early diagnosis and treatment matter in Sjögren’s disease

Since B-cell activity is constant in Sjögren's, getting an accurate diagnosis and starting treatment early is critical and may help mitigate or reduce risks associated with the disease.¹⁵ For example, people living with Sjögren's have a lymphoma risk 10 to 44 times higher than the general population, and about 1 in 5 develop interstitial lung disease, but the risk can potentially be reduced through consistent disease management and regular monitoring.^16,17 That is why it is so important for patients to work with their healthcare team to manage their disease.

5. The same biology behind Sjögren's disease can drive other autoimmune diseases

B-cell dysregulation reaches beyond Sjögren's disease. It has been identified as a shared driver across multiple autoimmune conditions, including lupus and systemic sclerosis.⁴ That's why researchers are increasingly focused on B-cell biology as a common thread. Understanding this shared mechanism could change how these conditions are understood and managed, moving toward a future treatment that addresses the underlying autoimmune disease.

In progressive autoimmune diseases like these, B cells are always active—even on the days when a person feels well.³ Understanding that is one of the most important tools a patient can have. Driven by this challenge, Novartis prioritizes immunological research to decode the shared biology of B-cell driven diseases and engineer treatments that surpass today's standard of care.

Learn more about Sjögren's disease  and other B-cell driven autoimmune diseases.