Regulatory T cell frequencies in patients with rheumatoid arthritis are increased by conventional and biological DMARDs but not by JAK inhibitors

Regulatory T (Treg) cells play an important role in controlling immune responses. Their frequency is decreased in many autoimmune diseases, including rheumatoid arthritis (RA). We read with great interest the article by Rosenzwajg et al which presents the results of a clinical trial with low-dose interleukin-2 (ld-IL-2).1 The authors report that Treg cell frequencies were significantly increased following ld-IL-2 administration in 46 patients...