| Description: |
Differentiating drug-induced liver injury (DILI) and autoimmune hepatitis (AIH) is a diagnostic challenge. Liver biopsy is recommended in unclear cases, however, clear distinguishing patterns are unknown. We therefore aimed to further identify histopathological features that can discriminate DILI from AIH. The clinical and histological data of well-characterised 136 DILI and 43 AIH patients from our prospective cohort on patients with acute liver injury and potential drug-related cause were analysed. Logistic binary regression was performed to identify models that could differentiate both two entities. Histopathological findings showed high overlaps between DILI and AIH, and overall concordance between histological and clinical diagnosis was low (48.9%). While interface hepatitis, plasma cell infiltration, and portal-intralobular infiltration were favouring AIH, relevant proportions of DILI patients also presented with those features (44.1%, 46.3% and 29.2%, respectively). Interestingly, on multivariate analysis, lipofuscinosis was the only independent predictor of DILI diagnosis, showing a strong association with DILI diagnosis (odds ratio [OR] 10.8; positive predictive value [PPV] 96.2%). Moreover, logistic regression analysis showed that a model combining different histopathological features (lack of interface hepatitis, fibrosis and eosinophils together with presence of cholestasis, steatosis and lipofuscinosis) could differentiate DILI from AIH with an accuracy of 76.5% and a strikingly high sensitivity of 94.9%. DILI and AIH showed similar histological patterns, however lipofuscinosis was identified as a novel distinctive feature for DILI with an extraordinarily high PPV. Moreover, a model combining a variety of histological features could differentiate both entities with high sensitivity. |