Primary Sclerosing Cholangitis (PSC): Advances in Diagnosis, Risk Stratification, and Emerging Therapeutic Strategies

Overview

This lecture by Dr. Omar Mousa, transplant hepatologist at Mayo Clinic Florida, provides a comprehensive update on Primary Sclerosing Cholangitis (PSC), covering advances in diagnosis, non-invasive risk stratification, emerging biomarkers, and evolving therapeutic and management strategies relevant to clinical hepatology practice.

Key Clinical Topics

• Epidemiology and natural history of PSC
• Diagnostic algorithm and serologic evaluation, including novel biomarkers
• Imaging strategies: MRCP, MRI, and the role of ERCP
• Differential diagnosis and exclusion of secondary sclerosing cholangiopathies
• Liver biopsy: indications and limitations in PSC
• PSC-associated inflammatory bowel disease (IBD)
• Risk stratification and prognostication
• Malignancy surveillance in PSC
• Liver transplantation considerations
• PSC in pregnancy

Key Learning Points

• Natural history: PSC is a progressive cholestatic liver disease; transplant-free survival is approximately 20 years, with many patients experiencing a prolonged preclinical phase before symptom onset
• Symptom prevalence: Nearly half of adult PSC patients present with symptoms; of asymptomatic patients, approximately 20% develop symptoms within 5 years of diagnosis, commonly including fatigue, abdominal pain, pruritus, fever, anxiety, and depression
• IBD association: More than two-thirds of PSC patients have concomitant IBD, with disease activity that changes over time
• Biochemical profile: Approximately 75% of patients present with a cholestatic biochemical pattern; elevated aminotransferases are common but do not automatically indicate autoimmune hepatitis overlap
• Serologic markers: ANA, ASMA, and p-ANCA have minimal diagnostic implications in PSC
• IgG4 exclusion: IgG4 levels should always be checked; a level >5.6 g/L suggests IgG4-related sclerosing cholangitis rather than PSC
• Novel biomarker — anti-integrin αVβ6 autoantibody: A promising emerging biomarker expressed by intestinal and biliary epithelium; implicated in TGF-β-dependent ductal proliferation and biliary fibrosis; correlates with alkaline phosphatase, the revised Mayo PSC risk score, and liver stiffness; levels fluctuate throughout the clinical course and are not yet clinically available
• MRCP as primary imaging modality: Preferred for identifying biliary strictures; ERCP should not be used for diagnostic purposes
• Equivocal MRCP: Guidelines recommend repeat MRCP at an experienced center; if suspicion remains high, repeat imaging at one year
• Small duct PSC: Liver biopsy is indicated when MRCP is normal but clinical suspicion remains high, or to exclude autoimmune hepatitis overlap
• Liver biopsy limitations: Classic onion-skin periductal fibrosis is infrequently observed and not pathognomonic; biopsy is not recommended for routine fibrosis staging when MRCP has already confirmed diagnosis due to sampling variability and slow histologic change
• Secondary sclerosing cholangiopathies to exclude: COVID-19-related cholangiopathy, HIV-related cholangiopathy, parasitic infections, IgG4-related disease, lymphoma, biliary surgical trauma, drug-induced cholangiopathy (including immunotherapies and ketamine)
• ASLD 2023 Guidance: Provides an updated diagnostic algorithm for the evaluation of suspected PSC

Clinical Data & Study Results

• Anti-integrin αVβ6 — Japanese cohort: Sensitivity 82.7%, specificity 94.4% for PSC versus comparator conditions including PBC, autoimmune hepatitis, and IgG4-related cholangitis
• Anti-integrin αVβ6 — CGH publication (United States): Demonstrated correlation with alkaline phosphatase, revised Mayo PSC risk score, and liver stiffness; notable finding that levels changed over the clinical course in individual patients

Practical Takeaways