What role do maternal cells play in the development of pediatric lupus?
Rheumatologists know that patients with lupus develop antibodies to their own proteins, and that B lymphocytes make the antibodies with help from T lymphocytes. But the source of T lymphocyte reactivity has eluded scientists for decades.
Dr. Anne Stevens, a physician-scientist at Seattle Children’s, believes maternal cells — which are transported to a fetus during pregnancy and persist through a child’s lifetime — might play a role in pediatric lupus. With funding from the National Institutes of Health, Stevens is leading a study of T lymphocytes in healthy children and children newly diagnosed with lupus to test for reactivity to maternal cells. The study is enrolling children at 10 medical centers across the United States.
Immune system “overreacts” to maternal cells
“Our preliminary research has shown that healthy kids’ immune systems are tolerant of their mothers’ cells, while kids with lupus seem to overreact,” Stevens explains. “But we need to study more patients before we can draw a definitive conclusion.”
If maternal cells prove to be a culprit, Stevens says scientists would have a great opportunity to develop targeted treatments for children with lupus. “Maternal cells are present in about one in a million cells,” says Stevens. “That’s a small number of cells. If we could develop a therapy that blocks reactivity to the maternal cells or eliminates them altogether, it could be very successful with few side effects — unlike today’s lupus treatments, which are extremely immunosuppressive and toxic.”