In a breakthrough study, researchers at Northwestern Medicine and Brigham and Women's Hospital have identified a key discovery that may explain the development of lupus, one of the most common autoimmune diseases in the United States. The study, published in the journal Nature, highlights abnormalities in the immune systems of individuals with lupus, suggesting a clear pathway for the disease's progression.

For years, scientists have suspected that genetics, hormones, environmental factors, such as viral infections or exposure to specific chemicals, may predispose individuals to lupus. However, this new research delves deeper into understanding the disease's origins.

The study analyzed blood samples from 19 people with lupus and compared them to samples from healthy individuals. The comparison revealed that individuals with lupus have an imbalance in the types of white blood cells known as T cells. Specifically, they have an excessive presence of a particular T cell associated with damaging healthy cells and a deficiency of another T cell responsible for repair.

At the core of this imbalance lies a protein called interferon, which is crucial in defending the body against pathogens. Previous studies had shown that people with lupus have elevated levels of type I interferon. However, this study finds that a surplus of type I interferon can hinder the production of T cells that aid in healing wounds on the skin, lungs, and gut. Conversely, it stimulates the production of T cells involved in creating autoantibodies, which attack healthy cells and are a defining characteristic of lupus.

Dr. Deepak Rao, a rheumatologist at Brigham and Women's Hospital and one of the study authors, believes this theory could potentially explain the vast majority of lupus cases. However, other experts caution that lupus is a complex disease with diverse symptoms and contributing factors. They believe it may be premature to conclude that there is a singular root cause for all instances of lupus.

Despite the need for further research, the findings of this study offer hope for improved treatments in the future. The researchers found that administering anifrolumab, a drug that blocks interferon, to individuals with lupus helped restore the T-cell imbalance associated with the disease. Additionally, the study showed that activating the aryl hydrocarbon receptor, a protein regulating the body's response to bacteria and pollutants, limited the accumulation of disease-promoting T cells.

Dr. Jaehyuk Choi, a dermatologist at Northwestern Medicine and one of the study authors, suggests that future treatments for lupus may involve infusions or pills that target these specific abnormalities. However, challenges remain in finding ways to administer these treatments without triggering side effects throughout the entire body.

Lupus affects more than 200,000 people in the U.S., primarily women, according to the Centers for Disease Control and Prevention. Common symptoms include extreme fatigue, joint pain, and skin rashes. In severe cases, lupus can lead to kidney or heart damage, or weaken the immune system, making individuals more susceptible to infections.

The availability of a targeted and effective treatment for lupus would be a significant breakthrough for those living with the disease. However, experts stress that a one-size-fits-all approach may not be feasible, and a combination of therapies may be necessary to provide comprehensive care for individuals with lupus.

Further testing and research involving larger sample sizes are needed to validate these findings and explore their potential in the development of new treatments. While there is still much to uncover about lupus, this study represents a crucial step towards understanding the disease's root cause and providing hope for improved outcomes for those affected.