Background and aim: Drug-induced liver injury (DILI) may present with autoimmune features and require immunosuppressive therapy (IST) to reach biochemical response. Discontinuation of IST without hepatitis relapse may be more frequent in these patients as compared to patients with classical autoimmune hepatitis (AIH). We aimed to determine baseline characteristics and outcome of patients with immune-mediated drug induced liver injury (IMDILI) with particular emphasis on IST during follow-up.

Methods: We performed a single-center retrospective study of consecutive patients presenting at a tertiary care center between January 2005 and December 2019 either with IMDILI or with classical AIH, for whom full baseline characteristics and a close follow-up were available over a 12-month period.

Results: Overall, 31 patients (IMDILIn = 16, mean age 59 [34-74] years; AIHn = 15, mean age 47 [15-61] years) were included, showing similar biochemical, serological, and histological characteristics. Incriminating drugs in IMDILI patients were mostly represented by nonsteroidal antiinflammatory drugs and sartans. Initial corticosteroids combined with IST led to biochemical response in all patients. Compared to idiopathic AIH, more patients with IMDILI were weaned off corticosteroids at the end of follow-up (11/16 [68.7%]vs4/15 [26.6%],P < 0.02). At 1 year of follow-up, more patients in the IMDILI group compared to the classical AIH group were off any type of IST (13/16 [81%]vs15/15 [100%],P = 0.08).

Conclusions: Although presenting with similar baseline biochemical and histological characteristics as idiopathic AIH, patients with IMDILI may not require long-term IST.