Normally helpful immune system cells become harmful in patients with lupus. With a Novel Research Grant from the LRA, a team led by Dr. Frances Lund of the University of Alabama at Birmingham and Dr. Ignacio Sanz of Emory University in Atlanta and has discovered one possible reason why.
The immune cells known as B cells usually make proteins called antibodies that help us fight off bacteria and viruses. In patients with lupus, however, the cells produce antibodies that spur damage to the body’s healthy tissues. Patients with lupus have large numbers of mature B cells that can develop into cells that release these antibodies. Why some B cells become harmful in the disease is not clear.
Drs. Lund and Sanz suspected a type of interferon, a molecule produced naturally by the body that helps control the immune system. Some patients with lupus have high levels of this type of interferon in their blood. The researchers found that the interferon stimulates a newly defined population of recently activated B cells to transform into cells that could start making damaging antibodies as they mature further.
“Our results may explain why some B cells begin to make harmful antibodies,” says Dr. Lund.
“These findings may also have implications for lupus treatment,” comments Dr. Sanz.
One clinical trial has tested a drug that blocks this form of interferon, and it found negative results. But Drs. Lund and Sanz note that the trial did not include any African-American patients with severe kidney disease, who tend to have large numbers of the mature B cells that respond to the interferon. A second trial that included more of these patients might provide a better test of the drug, the researchers say.
The scientists’ paper appeared in the journal eLIFE.