The clinical implications of the biopsy findings in cases of drug-induced liver injury (DILI) are not fully elucidated. The aim of this study was to evaluate the histopathological findings of cases diagnosed as DILI and to correlate them with clinical and biochemical findings (such as causality assessment algorithms). We searched our department database for all cases of liver biopsy with findings consistent with toxic liver disease and selected those with a clinical diagnosis of DILI. The causative relationships were established according to Roussel Uclaf Causality Assessment Method (RUCAM). A total of 53 cases of DILI were reviewed, most of them diagnosed in hospitalized patients (83%). The analytical toxicity profile was hepatocellular (R > 5) in 60% of the cases and cholestatic (R < 2) in 26.4% of cases. The group of drugs most implicated was the anti-microbials (18, 34%). The predominant histological patterns were "necroinflammation" (67.9%) and "cholestasis" (28.3%). The hepatocellular biochemical pattern was not associated with the presence of predominantly necroinflammatory findings in the biopsy (p = 0.44), and the biochemical cholestatic pattern was not associated with the presence of predominantly cholestatic findings in the biopsy (p = 0.51). This study supports that a better insight into the pathologic mechanisms associated with DILI should be based on liver biopsy due to the lack of a uniform correlation between clinical and biochemical patterns. Also, a liver biopsy may be used in those cases where clinical suspicion of DILI persists despite a low score on current causality assessment algorithms.
Keywords: Drug toxicity; Drug-induced liver injury; Liver pathology; RUCAM.