Abstract: Objective The purpose of this study was to investigate the diagnostic value of liver biopsy under the guidance of ultrasound for patients with liver injury of unknown origin (LIUO). Methods A retrospective analysis was performed on 71 patients with LIUO who underwent liver biopsy in our hospital. The clinical data and pathological reports were summarized for further investigation. Results Out of the 71 patients with LIUO, 53(76.4%) presented with elevated serum ALT levels, 6(8.5%) with elevated serum bilirubin levels, 8 (11.3%) with liver cirrhosis of unknown origin, 2(2.8%) with portal hypertension of unknown origin, and 2 (2.8%) with bile duct dilatation; on the basis of clinical materials, the liver histopathological examination showed autoimmune liver diseases in 13 cases(18.3%), and out of them, primary biliary cholangitis in 8 cases, autoimmune hepatitis in 2 cases, over-lapping syndrome in 2 cases, and IgG4-related cholangitis in one case; non-alcoholic fatty liver diseases in 18 (25.4%), 14 out of them were non-alcoholic steatohepatitis; drug-induced liver injury in 17(23.9%), chemical liver injury in 4 (5.6%), alcoholic hepatitis in 2(2.8%), Gilbert syndrome in 2, Dubin-Johnson syndrome in one, Caroli's disease in one, idiopathic portal hypertension in one, glycogen storage disease-induced liver cirrhosis in one, non-A, non-B hepatitis in one, damaged bile duct in one case, left 9 cases(12.7%) still having non-specific liver inflammation undiagnosed. Conclusion On the basis of clinical materials, the liver histopathological examination could help diagnosis of patients with LIUO, which warrants further clinical investigations.

Key words: Liver injury of unknown origin, Liver biopsy, Histopathology, Diagnosis