What Causes Lupus' Impact on Immune System?

Certain cells seem to malfunction and create inflammation instead of fighting the disease, research say

By Amy Norton

HealthDay Reporter

TUESDAY, March 8, 2016 (HealthDay News) -- Scientists have found new clues that help explain what's going wrong in the immune systems of people with lupus -- insight they hope will lead to new therapies, or help guide current treatment choices.

Lupus has several forms, but the most common is systemic lupus erythematosus (SLE). In SLE, the immune system mistakenly produces antibodies against the body's own tissue. The onslaught can have widespread effects, damaging the skin, joints, heart, lungs, kidneys and brain, according to the Lupus Foundation of America.

The disease mostly strikes women, usually starting in their 20s or 30s, the foundation says.

In the new study, the researchers found evidence that in people with lupus, some of the immune system's "B cells" mature the wrong way -- so that they promote inflammation instead of fighting it.

The findings, published online March 8 in the journal Immunity, could help in developing new lupus therapies, said senior researcher Claudia Mauri. She is a professor of immunology at University College London in the United Kingdom.

In people without lupus, anti-inflammatory B cells appear to prevent excessive production of a protein called interferon-alpha, explained Mauri.

That's a critical job because too much interferon-alpha leads to too many B cells that produce antibodies, the study authors said. Antibodies are necessary soldiers in the body's defense against infection, but in lupus, some of those antibodies target the body itself.

"We will continue to work to develop new [treatment] strategies that harness the anti-inflammatory B cells in patients with SLE," Mauri said.

Right now, a number of drugs are used to treat lupus, including immune-system suppressors such as cyclophosphamide and tacrolimus, and anti-malaria drugs like hydroxychloroquine -- which can ease the fatigue, joint pain and skin rash that lupus commonly causes, according to the Lupus Foundation of America.

In some cases, doctors try a drug called rituximab, an IV medication designed to kill off certain B cells. Rituximab is approved to treat certain cancers and rheumatoid arthritis -- another autoimmune disease; but some lupus patients respond to the medication, too, the study authors said.