Juvenile idiopathic arthritis: disease-causing and protective cells identified

For the first time, the T lymphocytes in the joint of patients with Juvenile Idiopathic Arthritis, the most common rheumatic disease in childhood and adolescence, were extensively characterized by global gene expression analyses at the single cell level. Both pro-inflammatory and anti-inflammatory CD4 T lymphocytes were found. It was shown that in chronic inflammation these cells are indeed continuously activated by antigen, drive inflammation in the joint through cytokines and activate effector cells. Pro-inflammatory CD8+ T lymphocytes with a similar gene expression profile to their CD4+ counterparts have also been identified. They represent an interesting new therapeutic target.