Primary Biliary Cholangitis (PBC) is a chronic autoimmune cholestatic liver disease characterized by the progressive destruction of small intrahepatic bile ducts, leading to chronic cholestasis, hepatic fibrosis, and, in advanced stages, cirrhosis. Recent advances in the understanding of PBC pathophysiology have highlighted the central role of immune, inflammatory, and metabolic alterations in disease onset and progression.

The study will enroll patients with Primary Biliary Cholangitis (PBC) for whom treatment with PPAR agonists has been prescribed in routine clinical practice, either as first-line or second-line therapy according to current clinical indications.

The study procedures include:

• Collection of demographic, clinical, laboratory, and treatment-related data. All information will be retrospectively and prospectively collected from patients' medical records and routinely available clinical documentation.
• Collection of additional peripheral blood samples (10 mL) at baseline (T0) and after 3 months of therapy (T3). Blood sampling will be performed concurrently with routine blood draws already scheduled as part of standard clinical monitoring and follow-up of PBC patients, without requiring additional clinical visits or invasive procedures beyond standard care.

Inclusion Criteria:

• Age ≥ 18 years
• Confirmed diagnosis of PBC (biochemical criteria, antibody positivity and/or histological examination)
• The patient is a candidate for first- or second-line PPAR agonist therapy, as clinical practice, for the treatment of PBC
• The patient requires comprehensive metabolic monitoring, as per clinical practice
• Signed the informed consent form

Exclusion Criteria:

• Patients with a prior diagnosis of diabetes mellitus currently on insulin therapy
• Patients on treatment known to significantly affect glycemic values (e.g., GLP-1 receptor agonists, SGLT2 inhibitors, systemic corticosteroids)
• Patients with a life expectancy or estimated time to liver transplantation of less than 6 months

PBC patients initiating PPAR-agonist therapy in first or second line as part of routine clinical care.