Researchers at Southfield-based Beaumont today announced they are pioneering a way to use patients’ immune systems to prevent arthritis following anterior cruciate ligament (ACL) knee injuries.
As many as 200,000 ACL knee injuries occur every year, often in people under 30. The injuries are painful and can lead to post-traumatic osteoarthritis (PTOA) and eventual knee replacements.
The U.S. Department of Defense awarded Kevin Baker, director of orthopedic research at Beaumont, a $1.5-million grant to study methods to modify the immune system’s response to an ACL rupture and encourage a patient’s own stem cells to slow or eliminate the joint degeneration associated with PTOA.
“We developed a strategy to reduce the body’s immune system response to a joint injury,” says Baker. “The immune system can do more harm than good when this kind of trauma occurs. We are encouraging stem cells to migrate to the ACL-injured joint and then treating the cells with a drug. We believe changing the immune response inside the joint will significantly diminish or prevent PTOA.”
The immune system works by attacking foreign cells without harming normal ones. To do this, the body uses “checkpoint” molecules that need to be activated or inactivated to start an immune response. These molecules have been the focus of recent advances in cancer immunotherapy, in which medications inhibit checkpoint molecules that cancer cells overproduce.
Baker and his team are using one of the checkpoint molecules to minimize the immune system’s overexuberant response to an ACL injury. The body’s own stem cells also release the checkpoint molecules and other proteins that can modulate the immune system. The researchers will focus on using this immune altering approach to slow or eliminate damage that occurs to both cartilage and bone as a result of joint injury.
Post-traumatic osteoarthritis is the leading cause of disability in U.S. military service personnel, and the rate of PTOA in military personnel is more than double that of civilians. Joint injuries, often ruptured ACLs, are the primary reason PTOA develops in the knee. More than $3 billion each year is spent on health care costs associated with PTOA in the U.S.