Mayo Clinic research shows that chronic exposure to even small amounts of Staphylococcus aureus (staph) bacteria, which is frequently found on the skin or in the nose, could present a risk factor for developing the chronic inflammatory disease lupus. The study is published online in the August edition of The Journal of Immunology.

In an animal study, the researchers exposed mice to low doses of a protein found in staph and discovered that the mice developed a disease similar to lupus, with kidney disease and auto-antibodies comparable to those found lupus patients' blood.

Co-author Vaidehi Chowdhary, M.D., a Mayo Clinic rheumatologist noted that the next step is to examine lupus patients to investigate whether the effect of this particular staph protein is similar in humans, saying:

"We think this protein could be an important clue to what may cause or exacerbate lupus in certain genetically predisposed patients. Our hope is to confirm these findings in lupus patients and hopefully prevent flares."

Lupus is an incurable disease, which develops when the immune system attacks tissues and joints, which means that it can affect almost any part of the body. The condition can be difficult to diagnose as it often mimics other ailments and the only treatment available is to control symptoms. Lupus occurs more frequently in women, African-Americans, Hispanics, Asians and people between the ages of 15 to 40.

The key question is whether treating those at-risk in order to eradicate staph could stop lupus from developing in the first place.

The cause of lupus is often unknown, although it seems that those who are genetically predisposed to lupus could develop it when environmental factors, like infections, certain drugs or even sunlight triggers it. Because there is no known cause, Cr. Chowdhary says that the discovery of the staph protein's possible function is exciting.

In the mouse experiment, a staph protein called staphylococcal enterotoxin B (SEB) was seen to activate autoreactive T and B lymphocytes, which led to a similar inflammatory illness to lupus. Studies on humans have revealed that the presence of staph bacteria is associated with autoimmune diseases like psoriasis, graulomatosis with polyangiitis, and Kawasaki disease.

Written by Grace Rattue