In an advance that may lead to new therapies to treat inflammatory arthritis, scientists have identified the initial steps leading to joint inflammation using a novel approach for imaging movement of immune cells in living animals.
Researchers found that expression of a specific molecule – complement C5a – is required to cause the immune cells called neutrophils to adhere to joint surfaces and migrate into the joint, a process known to set off the inflammatory cascade. “Inflammatory arthritis is caused when immune cells are recruited from the blood into the joint in a highly regulated process controlled by chemoattractants and adhesion receptors,” said Andrew Luster from the Massachusetts General Hospital (MGH) in the US.