Characterisation of Patients With Primary Biliary Cholangitis in Austria - A Prospective Registry and Biobank

This is a prospective, multicenter registry of patients with primary biliary cholangitis (PBC). Patients presenting to hepatology outpatient clinics at participating centers in Austria will be offered inclusion in the registry. For patients who are already under care at the respective center at the time of enrollment, retrospective data will be collected and subsequently complemented with prospective follow-up data. Registry participants will be managed according to current treatment guidelines and standard clinical practice at the discretion of the individual investigators. Demographic, clinical, and laboratory parameters will be recorded at the time of registry inclusion and subsequently at follow-up visits. The frequency of clinical visits will be determined by clinical necessity and will generally occur every 3-6 months, although shorter intervals may be required. No study-specific interventions will be performed. If diagnostic material is obtained as part of routine clinical care (e.g., blood sampling or liver biopsy), patients will be asked to provide informed consent for the storage of additional material (blood) or residual material (liver biopsy specimens) in a biobank for research purposes. Next to the detailed characterization of patients by epidemiologic, clinical and laboratory parameters, the presence of overlapping liver disease etiologies and the severity of liver disease will be assessed. Specifically, this includes the assessment of liver-related complications including events of hepatic decompensation, measurements of liver and spleen stiffness, as well as an assessment of portal hypertension severity based on imaging findings and hepatic venous pressure gradient measurement in selected patients. Furthermore, assessments include a detailed evaluation of current and prior disease-specific treatments and extrahepatic symptom burden. Data will be entered into a pseudonymized database by study personnel. Data transfer from participating centers to the Medical University of Vienna will be conducted either via encrypted electronic transfer or by direct transfer using encrypted hardware (e.g., hard drives or USB devices). Patient identifiers (e.g., name) will not be entered into the database. All other patient data will be recorded as datasets in a pseudonymized data table. All participating patients will be assigned a consecutive study number, thereby ensuring pseudonymization for subsequent analyses. This pseudonymization through assignment of a unique study number will also apply to samples stored in the associated biobank. Access to the data will be restricted to authorized personnel. A stated objective of the registry is the systematic inclusion of patients with PBC-associated liver disease who are managed at the specialized outpatient clinic of Vienna General Hospital or at specialized outpatient clinics of participating centers. This is particularly relevant from an epidemiological perspective to determine and capture the number of patients across different clinical stages of the disease. Therefore, the aim is to include all patients with PBC who are willing to participate from these specialized outpatient clinics, and no formal sample size calculation has been performed. Participants included in this registry are unlikely to derive any direct benefit from participation. As participation in the registry and the associated biobank does not involve any invasive procedures, no relevant risks are expected. Patients may withdraw their participation in the registry and/or the biobank at any time.