Researchers from Northwestern Medicine and Brigham and Women’s Hospital have uncovered a potential root cause of lupus, one of the most common autoimmune diseases, potentially opening doors to new treatments. The study, published in the journal Nature, highlights an imbalance of T cells in patients with lupus, offering new insights into the disease’s development.

Lupus affects hundreds of thousands of people in the U.S., with symptoms ranging from extreme fatigue and joint pain to skin rashes and, in severe cases, kidney or heart damage. Historically, the disease has been difficult to treat, with many therapies broadly suppressing the immune system, often with limited effectiveness.

The study compared blood samples from 19 lupus patients with those from healthy individuals, revealing that lupus patients have an excess of a T cell type associated with cellular damage and a deficiency in a T cell type crucial for repair. This imbalance is linked to a protein called interferon, which, in excess, blocks the aryl hydrocarbon receptor that regulates responses to bacteria and pollutants. This blockage hinders the production of repair-promoting T cells while stimulating the creation of autoantibodies, a hallmark of lupus.

Dr. Deepak Rao, one of the study’s authors, suggests that this imbalance could explain most lupus cases. However, experts like Mara Lennard Richard from the Lupus Research Alliance caution that it’s premature to declare this the singular cause of lupus, citing the disease’s varied symptoms and contributing factors.

The study also explored potential treatments. Administering anifrolumab, a drug that blocks interferon, corrected the T-cell imbalance in lupus patients. Additionally, activating the aryl hydrocarbon receptor in blood samples limited disease-promoting T cells. Despite these promising results, Dr. Jill Buyon from NYU Langone Health notes that broader studies are necessary to confirm the findings and that a single treatment may not work for all lupus patients.

This groundbreaking research provides hope for more targeted and effective lupus treatments, though further investigation and clinical trials are needed to fully understand and apply these findings.