Certain cells from a mother persist in their children’s bodies and can provoke an immune response in which the child’s body attacks itself, according to
Mayo Clinic research published in the current issue of the
Journal of Immunology (
http://www.jimmunol.org). The findings are important not only in seeking the cause and treatments of this disease, but also in understanding an entire class of autoimmune disorders.
Juvenile dermatomyositis (der-mat-o-my-o-SITE-us), or JDM, is a rare muscle-damaging condition that causes a child’s immune system to attack the body, as if it were an invading life form. Muscles deteriorate and the child becomes weak and fragile. There is no cure for JDM. Current treatments include medication, physical therapy and added nutrition.
“The key aspect of our study suggests a mechanism for the disease, and deepens our understanding of autoimmune disorders in general,” says pediatrician and lead investigator Ann Reed, M.D. “And because we studied a larger population of JDM patients and control groups than has ever been studied, we can feel confident in our results.”
Significance of the Mayo Clinic Research
In the largest study of its kind, Mayo Clinic researchers examined 72 JDM patients, with an average age of 10. They compared them to siblings who did not have the disease, as well as to a control group of healthy children. Several key findings emerged:
Most JDM patients carry a particular gene (labeled HLA) which they received from their mother during pregnancy.
When a child has the HLA gene on a mother’s cell, it triggers an immune response against the child.
These cells may be part of the mechanism that causes JDM.
Researchers have known for years that fetal cells can be found in women several years after giving birth. They have thought these may contribute to the development of autoimmune diseases in women during and after their childbearing years. In the current study, the Mayo Clinic group looked at the opposite situation: persistence of maternal cells in children.