Why Autoimmune Diseases Rise Sharply After 50: Scientists are making progress in treating these disorders, which can go unrecognized for years

 

“Fatigue, joint pain, rashes, brain fog or tingling in the hands and feet can seem like normal signs of aging -- but they may also point to an autoimmune disease.

 

These potentially disabling and often poorly understood conditions -- including rheumatoid arthritis, lupus and Type 1 diabetes -- occur when the immune system mistakenly attacks the body's own cells and tissues. Many of these conditions emerge only in midlife and beyond. A Mayo Clinic study published last December found that autoimmune-disease rates rise sharply after 50 and climb even higher after 65 -- in part because cases can go unrecognized for years.

 

Scientists are now making rapid progress in understanding and treating these disorders, developing more-precise diagnostic blood tests and novel therapies. The National Institutes of Health, which partly funded the Mayo study, launched an initiative in July to coordinate autoimmune research across its institutes, aiming to speed discovery, improve diagnosis and treatment, and get a better handle on how many Americans live with autoimmune conditions. Estimates range from 15 million to as many as 50 million.

 

Part of the problem in diagnosing autoimmune disorders is that symptoms can overlap with dozens of other conditions. Widely used blood tests may reveal unusual immune activity but often fail to pinpoint the exact problem. The same immune markers that show up when the body fights infection can also appear in several autoimmune diseases -- or even in people who never develop one.

 

Meanwhile, autoimmune conditions become more common with age as the immune system changes. The brief bursts of inflammation that the body once used to fight infection can linger. This creates a constant, low-grade burn known as inflammaging that can confuse the immune system, making it more likely to mistake the body's cells for an invader.

 

"The autoimmune diseases that appear later in life are due to the combined effect of aging and the fact that it takes forever sometimes for people to get diagnosed," says study author Dr. DeLisa Fairweather, an immunologist who heads translational research for the department of cardiovascular medicine at Mayo. "People are getting diagnosed later for diseases that may have started when they were 40."

 

According to the NIH, multiple genetic and environmental factors interact in complex ways over decades. Infections, hormonal shifts and even gut microbes can trigger disease in susceptible people. Researchers are studying whether Covid-19 infections might accelerate autoimmunity, and whether chronic stress, certain prescription drugs or long-term exposure to "forever chemicals" in water and packaging might contribute. Women are affected far more often than men, in part because of the immune changes that protect pregnancy.

 

A promising new line of research centers on the immune system's regulatory T cells -- the natural brakes that prevent it from attacking healthy tissue. A 2025 Nobel Prize went to three scientists who discovered how these cells work and the gene that controls them. Their findings are being tested with diseases such as rheumatoid arthritis.

 

At Stanford University's School of Medicine, researchers led by Dr. Scott Boyd have developed an AI-based blood-testing approach to scan the immune system for signs that these braking mechanisms are failing. The system uses machine learning to analyze millions of immune-cell receptors -- the molecular fingerprints left as the body responds to threats -- and detect patterns linked to autoimmune activity.

 

By spotting these warning signs in a simple blood sample, researchers hope to diagnose autoimmune diseases faster and more precisely, and predict which treatments might work best for a particular patient.

 

Scientists are also developing faster, more accurate tools to diagnose autoimmune blistering diseases -- conditions that occur when the immune system attacks proteins that hold skin layers together. At the Mayo Clinic, dermatologist Dr. Julia Lehman and her team developed a blood test that directly detects the specific antibodies behind these painful disorders, which can affect the skin, eyes or mouth, and are often mistaken for eczema or hives early on. The new test helps doctors match treatments more precisely to each disease and predict the presence of associated medical conditions as well as each patient's response to treatment, Lehman says.

 

Some treatment breakthroughs are already reaching patients. In rheumatoid arthritis, where the immune system attacks joint linings, biologic drugs can control inflammation and prevent damage -- though they may also raise infection risk or cause fatigue and nausea.

 

As an alternative to current treatments, an implantable device made by SetPoint Medical was recently approved by the Food and Drug Administration for people with moderate to severe rheumatoid arthritis who haven't responded to, or were intolerant of, other treatments.

 

The device is based on findings by SetPoint co-founder Dr. Kevin Tracey, who heads the Feinstein Institutes for Medical Research at Northwell Health in New York.

 

He discovered that the vagus nerve -- which connects the brain to many organs -- can send electrical signals that suppress the inflammatory response. In clinical trials, patients with rheumatoid arthritis who received mild electrical pulses to the vagus nerve from the implant had fewer flare-ups and lower disease activity.

 

While there is no sure way to prevent autoimmune disease, research suggests keeping chronic inflammation in check -- through a healthy diet, regular exercise, good sleep, stress control, and maintaining a healthy weight -- can help support a calmer, more balanced immune system.

 

Scientists continue to look for new ways to keep the immune system strong to help older adults fight infections and cancer. But some evidence suggests having the immune system age in tandem with the body could have benefits. More than 100 patients in their 60s and 70s treated at Mayo for an autoimmune disease that attacks the arteries had unusually vigorous immune systems that had not slowed with age, dubbed "immune youth." But instead of protecting them, according to a study, their youthful immune systems attacked their normally aging tissues as if they were foreign invaders.

 

Without the means to rejuvenate the entire body, warns Dr. Cornelia Weyand, director of Mayo's program in immunity and inflammation and co-author of the study, "rejuvenating the immune system alone creates the risk of autoimmune disease."

 

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Laura Landro, a former Wall Street Journal assistant managing editor, is the author of "Survivor: Taking Control of Your Fight Against Cancer." She can be reached at reports@wsj.com.” [1]

 

1. Encore (A Special Report) --- Why Autoimmune Diseases Rise Sharply After 50: Scientists are making progress in treating these disorders, which can go unrecognized for years. Landro, Laura.  Wall Street Journal, Eastern edition; New York, N.Y.. 24 Nov 2025: R10.