Response to: ‘Regulatory T cell frequencies in patients with rheumatoid arthritis are increased by conventional and biological DMARDs but not by JAK inhibitors’ by Meyer et al

Commenting on Meyer et al 1 our recent publication2 ‘Immunological and clinical effects of low-dose interleukin-2 (IL-2) across 11 autoimmune diseases in a single, open clinical trial’, Dr Meyer and colleagues point to the issue of concomitant background therapies that could affect the effects of low-dose IL-2. They reported a significant increase of Treg cell frequencies in peripheral blood of patients with rheumatoid arthritis treated with methotrexate, adalimumab, etanercept, golimumab and tocilizumab, which they discuss could affect the increase expected after an IL-2 treatment. Only four rheumatoid arthritis patients were included in our study, all being treated with low-dose corticosteroids and/or low doses of immunosuppressants. Their baseline Treg evaluation was similar to that of patients with other diseases treated with …