Patients With Cryptogenic Hypertransaminasemia

Overview

Persistent unexplained elevation of serum aminotransferases (ALT and AST) remains undiagnosed in a subset of patients despite a comprehensive diagnostic work-up. Increasing evidence suggests that alterations in the gut-liver axis, including intestinal dysbiosis, increased intestinal permeability, and bacterial translocation, may contribute to liver inflammation and hepatocellular injury. Bacterial components such as lipopolysaccharide (LPS) may reach the portal circulation and activate hepatic immune pathways through receptors including CD14 and Toll-like receptor 4 (TLR4). This study aims to investigate the potential role of bacterial translocation in patients with unexplained persistent hypertransaminasemia undergoing liver biopsy. Standard histological evaluation will be integrated with immunohistochemical and molecular analyses of liver biopsy specimens to assess markers associated with bacterial translocation, including bacterial DNA, LPS, and soluble CD14 (sCD14). The study may help clarify the underlying mechanisms of otherwise unexplained hypertransaminasemia and identify potential biomarkers for future clinical use.

The study will involve the collection of clinical, demographic, anthropometric, laboratory, medication, and imaging data from patients with persistent unexplained hypertransaminasemia. Relevant laboratory parameters will include liver function tests, metabolic parameters, complete blood count, glycated hemoglobin, and hepatitis B and C serological markers. Additional biological samples will be collected during routine clinical procedures, including a 10 mL blood sample, a liver tissue specimen obtained during clinically indicated liver biopsy, and a stool sample. Liver tissue will undergo standard histological evaluation and additional immunohistochemical analyses. Blood and stool samples will be analyzed to investigate markers of bacterial translocation, intestinal microbiota composition, and inflammatory profiles, with the aim of better characterizing the gut-liver axis and its potential role in unexplained hypertransaminasemia. All clinical data and biological samples will be collected only after obtaining written informed consent from participants, in accordance with the approval of the competent Ethics Committee. Biological samples and study-related data will be stored and processed at Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome.