Defining characteristics and long‐term prognosis of drug‐induced autoimmune‐like hepatitis: A retrospective cohort study

Abstract

AbstractBackgroundDrug‐induced autoimmune‐like hepatitis (DI‐AILH) is poorly defined and more data are required to better characterise and manage this disease entity.ObjectivesThe aim of this study was to evaluate the clinical characteristics, histology and long‐term outcomes of DI‐AILH compared with idiopathic autoimmune hepatitis (AIH).MethodsThis retrospective cohort study reviewed 28 DI‐AILH and 39 AIH patients in a single centre. The new (2022) and simplified (2008) AIH histology criteria were used to assess DI‐AILH.ResultsDI‐AILH were more likely to present with jaundice (p = 0.004) and higher bilirubin levels (p = 0.04) than AIH. AIH patients had higher rate of immunosuppression (IS) use including second‐ and third‐line agents, though the time to reach biochemical remission were comparable. AIH patients had more advanced fibrosis than DI‐AILH (Ishak fibrosis score 3.5 vs. 1.9, p < 0.0001). DI‐AILH more commonly had eosinophilic aggregates (18% vs. 3%, p = 0.031) and less commonly showed plasma cell aggregates (61% vs. 97%, p < 0.001) than AIH. The simplified AIH histology criteria identified 1 atypical histology within the DI‐AILH cohort, although this patient required long‐term IS. The new AIH histology criteria classified 23 (82%) as likely AIH and 5 (18%) as possible AIH. Two of the possible DI‐AILH did not require IS and one patient had successful IS withdrawal. Four DI‐AILH patients with fibrosis stage ≤3 had successful IS withdrawal compared with none in the AIH group. Four patients underwent liver transplantation (LT) in both cohorts with significantly shorter time to LT in DI‐AILH as the indication was for (sub)acute liver failure. Two DI‐AILH patients died within 60 days of LT.ConclusionThe new AIH histology criteria may be better at identifying DI‐AILH. Immunosuppression withdrawal in those without significant fibrosis may be considered. DI‐AILH is at risk of (sub)acute liver failure and early discussions with a transplant centre would be desirable.