Problems in cellular cleanup may contribute to lupus

Every day in the body millions of cells die. Some of those cells are old, worn out, unneeded or unwanted. Disposing of all those cells can be a challenge. Defects in the process have been linked to inflammatory disease and other health problems.

St. Jude Children’s Research Hospital scientists have discovered how problems in part of the disposal process may lead to the autoimmune disorder lupus.

Lupus occurs when the immune system mistakenly makes antibodies that attack healthy tissue. This causes widespread inflammation. People with lupus may also have life-threatening damage to the kidneys and other organs. The most common form of the disease is systemic lupus erythematosus or SLE. About 322,000 people in the U.S., mostly young women, have SLE.

In the lab, researchers showed that defects in a cell digestion process called LAP can cause a lupus-like illness. LAP ensures that dead cells are digested and disposed of properly. The research showed that defects in LAP led to increased inflammation and other immune system changes seen in SLE.

“We hope the findings offer a window into the cause of this devastating disease in some patients,” said Douglas Green, PhD, chair of the St. Jude Department of Immunology. He led the scientific team that discovered LAP in 2007.

“We also hope the discovery will pave the way for developing new strategies to prevent or reduce the inflammation and autoimmune response that characterize lupus,” Green added.

The research was published in Nature.

Read the news release.