Chronic Inflammation in Rheumatoid Arthritis Attributed to Hibernating Cells

Innate lymphoid cells typically manage the resolution of inflammation in healthy individuals; however, it remains unclear how the inflammation is cleared or why the same process does not occur in patients with rheumatoid arthritis (RA).

RA is a chronic disease that causes persistent inflammation that results in joint and bone damage. More than 1.3 million Americans are currently living with the disease.

“A particularly worrying aspect of those affected is the fact that the inflammatory response in joints is exceptionally chronic and thus usually requires lifelong treatment,” said Georg Schett, author of the study published in Nature Medicine.

Through a joint project, investigators have solved this mystery, finding that innate lymphoid cells go into a hibernation-like mode in patients with RA.

“In patients suffering from rheumatoid arthritis, these innate lymphoid cells are in a state of what can be described as hibernation and as a result the inflammation persists,” said principal investigator Dr Andreas Ramming. “When innate lymphoid cells are ‘woken up’, this puts a stop to the inflammation and to the damage to the joint.”

The findings could help develop new treatment options for patients with chronic inflammatory diseases, the authors noted.

Patients whose disease is in remission exhibited higher numbers of innate lymphoid cells in the joints and circulation. If there are too few of these cells in the blood, it will cause the disease to flare up and further damage the joint, according to the study.

Because resolution of inflammation is associated with elevated levels of innate lymphoid cells, the authors noted that measuring blood levels provides the ability to initiate more targeted treatments at an early stage to prevent another flare-up.

“These findings will make it possible to significantly improve the quality of treatment of rheumatoid arthritis in [the] future with the help of innate lymphoid cells,” Dr Ramming said.