Differential characteristics in drug‐induced autoimmune hepatitis

BACKGROUND AND AIM: Drug‐induced autoimmune hepatitis (DIAIH) is an adverse effect associated with several drugs that usually occurs acutely, with variable latency, and it may potentially be mortal. There are a few reports and studies about DIAIH. METHODS: This was an analytical study of a retrospective cohort of patients, discriminated according to idiopathic or drug‐induced etiology, followed up for a 7‐year period until 31 December 2016. RESULTS: A total of 190 patients were selected for the analysis, 12 (6.3%) with DIAIH. The two main drugs related to DIAIH were nitrofurantoin, n = 8 (67%), and NSAID, n = 2 (17%), constituting 84% of the cases. There were no significant differences in seropositivity between AIH with DIAIH in antinuclear antibodies (ANA) and anti‐smooth muscle antibodies (ASMA) antibodies, with 82.6% versus 82.6% and 34% versus 16%, respectively. The fibrosis stages were similar, except for the F4 stage, in a greater proportion in AIH. None of the patients with DIAIH had cirrhosis or developed it during follow‐up, but it was present in 42.1% of the AIH cases at diagnosis (P = 0.003). Biochemical remission with management was higher in DIAIH but not significant (91.7% vs 80.9%, P = 0.35). The definitive interruption of immunosuppression was successfully performed in 25% of those with DIAIH without relapses but was only possible in 2.8% in AIH (P < 0.001) with 32 cases of relapses. CONCLUSION: DIAIH constitutes a minor proportion of AIH. The clinical and histological characteristics may be similar; DIAIH patients have a greater chance of having treatment suspended with a low risk of relapse, progression to cirrhosis, or need for liver transplant.