Multicenter Validation Study of the Clinical Diagnostic Criteria for IgG4 ‐Related Sclerosing Cholangitis 2020 in Japan

BACKGROUND: The diagnostic performance of clinical diagnostic criteria for IgG4-related sclerosing cholangitis 2020 (IgG4-SC2020) has not been fully validated since its proposal as a revision of the 2012 criteria (IgG4-SC2012). METHODS: We conducted a multicenter validation study to evaluate the diagnostic performance of IgG4-SC2020 using clinical data collected from 1034 patients with IgG4-SC and 447 patients with mimickers, including 143 with pancreatic cancer, 157 with primary sclerosing cholangitis, and 147 with cholangiocarcinoma in Japan. RESULTS: The sensitivity of IgG4-SC2020 was significantly higher than that of IgG4-SC2012 (99.0% vs. 89.1%; p < 0.001). The specificities of both IgG4-SC2020 and IgG4-SC2012 were 100% for pancreatic cancer and cholangiocarcinoma. For primary sclerosing cholangitis, the specificities of IgG4-SC2020 and IgG4-SC2012 were 97.5% and 100%, respectively, with no significant difference (p = 0.123). A total of 113 patients who could not be diagnosed according to the IgG4-SC2012 were successfully diagnosed using IgG4-SC2020. These diagnostic improvements were attributed to the inclusion of MRCP findings (n = 97), the absence of neoplastic cells on histology (n = 15), and the presence of IgG4-related kidney lesions (n = 1). CONCLUSIONS: This Japanese multicenter validation study demonstrated that the diagnostic performance of IgG4-SC2020 was superior to that of IgG4-SC2012. TRIAL REGISTRATION: UMIN Clinical Trials Registry (UMIN-CTR), UMIN000052984.