Low‐Dose Interleukin‐2 for Refractory Autoimmune Hepatitis

The management of autoimmune hepatitis (AIH) has remained largely unchanged for the past three decades. The optimal regimen for patients who do not respond to first-line treatment of corticosteroids with or without azathioprine remains unclear. There is growing interest in the use of immunotherapies targeting cluster of differentiation 4–positive (CD4+) forkhead box P3–positive (Foxp3)+ regulatory T cells (Tregs). Tregs are a T-lymphocyte subpopulation with immunosuppressive and cytoprotective capacity that plays a key role in restraining autoreactive conventional T lymphocytes and preventing autoimmunity. Due to their constitutive expression of CD25, the alpha-chain of the interleukin-2 (IL-2) receptor, Tregs are highly dependent on, and exquisitely sensitive to, IL-2.(1) The use of lowdose IL-2 (LDIL-2) as an immunomodulatory agent is being explored in various autoimmune disorders.(2) We report here the clinical and immunological effects of LDIL-2 in 2 patients with refractory AIH.