The cause of lupus has long been unknown to doctors trying to treat this autoimmune disease.
However, a study published this week identified a cause of lupus based on molecular defects in patients’ blood. Lupus overproduces specific cells that attack the body’s organs and tissues. The incurable disease affects hundreds of thousands of people in the U.S.
Researchers are trying to find a balance with the cells to regulate lupus. Treatment currently relies on immunosuppressants to reduce inflammation and pain, but the drugs often don’t treat the disease effectively and their side effects hamper the body’s ability to fight off infection, researchers say.
“Until now, all therapy for lupus has been a blunt instrument. It’s broad immunosuppression,” study co-author Dr. Jaehyuk Choi, an associate professor of dermatology and a dermatologist at Northwestern Medicine, said in a statement. “By identifying a cause for this disease, we’ve found a potential cure that doesn’t have the side effects of current therapies.”
Choi’s colleagues at Northwestern and researchers at Brigham and Women’s Hospital in Boston participated in the study, published this week in the journal Nature. They compared blood samples from 19 patients with systemic lupus erythematosus, the most common form of lupus, and 19 patients without the autoimmune disease.
According to the Centers for Disease Control and Prevention, more than 200,000 people in the U.S. have lupus, but the nonprofit Lupus Foundation of America estimates that number is closer to 1.5 million. Most people with lupus are women and people of color. The disease is more common in black women, and they often suffer more severe forms of the disease and die from it at a higher rate than others, the CDC says. Most people with lupus survive, but the Lupus Foundation said that about 10 to 15 percent of people with lupus die prematurely due to complications from the disease.
Before the study was published this week, scientists had not identified a cause of lupus. Experts had hypothesized that genetics, environmental factors such as chemicals or viral infections, or immune and inflammatory influences were possible causes, the National Institutes of Health said.
People with lupus typically experience extreme fatigue, pain or swelling in muscles and joints, a skin rash such as a butterfly rash on their cheeks or nose, fever and hair loss. It causes problems throughout the body, including kidney failure, seizures and memory problems. It affects the brain and central nervous system and causes heart problems, according to the NIH.
The findings from researchers at Northwestern University and Brigham and Women’s may offer some hope, although the results are still early and based on a small sample of blood tests.
Researchers have identified a new cause of lupus. Patients in the study had a chemical imbalance that determined how their T cells, a type of white blood cell that is part of the immune system, responded to infection.
In an email, Choi said that lupus patients had too much of a protein called interferon, which helps fight infection, and too few aryl hydrocarbon receptor (AHR) proteins, which regulate the body’s response to infection. This resulted in an overabundance of disease-promoting cells that attacked the body. Replacing deficient AHR molecules with active ones could heal wounds instead of further injuring them, researchers say.
The researchers added AHR-activating molecules to blood samples from lupus patients, which appeared to reprogram the lupus-causing cells, allowing them to promote healing, a press release reported.
Choi said the study offers the potential for new therapeutic strategies in lupus treatment. The goal is to target the disease-causing cells to better protect patients from the disease.