A 20-Year Outcomesʼ Study of Patients With Immunoglobulin G4-Related Sclerosing Cholangitis: The Mayo Clinic Experience: 70

INTRODUCTION: Immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) has been recognized worldwide. However, its natural history and long-term outcomes are not well known. METHODS: In this retrospective, single center, cohort study, we identified patients who received a diagnosis of IgG4-SC at Mayo Clinic Rochester from 1999 to 2018. The diagnosis of IgG4-SC was rigorously ascertained by review of medical records and using the validated HISORt criteria. Comprehensive clinical data was extracted from patients' charts. Long-term outcomes of interest included cirrhosis, cholangiocarcinoma (CCA), and death. To compare outcomes, a random sample of PSC patients was selected in a 1:1 ratio matched for age of diagnosis and gender. Survival analyses were performed for comparisons using the Kaplan-Meier method, and log-rank test, and the cumulative incidence of cirrhosis and CCA was assessed using the competing risks regression method. RESULTS: A total of 61 patients were diagnosed with IgG4-SC during the study period. The median age of diagnosis was 66 years (IQR: 56–71 years), 85% were male, and the median follow-up was 6.1 years (IQR: 3.2–8.3 years). The pancreas was the most commonly involved extra-biliary organ (93%). Fifty-five patients received prednisone of whom 96% experienced complete or partial remission. Sixteen patients received rituximab as maintenance therapy, of whom 88% maintained remission. Three patients (5%) developed cirrhosis, and 2 patients (3%) developed CCA. Nine patients (15%) died; 2 due to cirrhosis, 2 due to CCA, 1 due to pancreatic cancer, and 4 due to non-hepatobiliary causes. Patients with IgG4-SC had significantly lower 5- and 10-year cumulative incidence of developing cirrhosis (5 y: 4% vs. 34%; 10 y: 6% vs. 43%; P < 0.001) and CCA (5 y: 3% vs. 17%; 10 y: 4% vs. 22%; P = 0.012) compared with PSC patients. Two patients in the PSC group underwent liver transplantation, while none in the IgG4-SC group. Overall 5- and 10-year survival was greater in the IgG4-SC cohort (5 y: 92% vs. 70%; 10 y: 77% vs. 57%; P = 0.02). CONCLUSION: Patients with IgG4-SC, the majority of whom received treatment, have a small potential risk of long-term hepatobiliary complications. Their risk of cirrhosis, CCA and death, was lower than in patients with PSC. The better outcome in the IgG4-SC group is likely due to the benefit of treatment. Surveillance in this population needs further assessment, especially the subset that does receive or respond to treatment.