Clinical and histological features of idiosyncratic liver injury: Dilemma in diagnosis of autoimmune hepatitis.

Aim: Drug-induced liver injury (DILI) is becoming a worldwide problem with its still unexplained properties.

Methods: The data of patients who were diagnosed with DILI between January 2008 and December 2013 were assessed.

Results: Five patients had been diagnosed with intrinsic and 82 patients with idiosyncratic DILI. The most common causative agents were antimicrobial drugs. The most common injury pattern was hepatocellular. When patients with bilirubin levels of more than 5 mg/dL were divided into two groups according to receiving steroid therapy (n = 11) or not (n = 40), there was not any significant difference according to their clinical results (P > 0.05). Five of the idiosyncratic DILI patients were diagnosed with drug-induced autoimmune hepatitis (DI-AIH). In histopathological examination, hepatic rosette formation and emperipolesis were observed to be more common among patients with DI-AIH when compared with ones without (P < 0.05). Interestingly, in the remaining patients with DILI (n = 77), three of them were diagnosed with classic autoimmune hepatitis during long-term follow up (range, 11-51 months).

Conclusion: The most common causes were antimicrobials, but any agents that have not been defined to cause DILI can induce DILI. The efficacy of steroids in DILI has not been observed but all deaths were observed in the steroid-free group. The association of DILI and AIH was observed in two different types in terms of diagnosis in our study. The first association was DI-AIH. The second one is the classical AIH which developed in three patients after a few months following spontaneous recovery of DILI.