Association between serum IgE level and adverse clinical endpoints in primary sclerosing cholangitis.

INTRODUCTION: Primary sclerosing cholangitis (PSC) is an idiopathic hepatobiliary disorder associated with an increased risk for cholangiocarcinoma (CCA) and a median survival time of 12 years. Reliable predictors of CCA and other major adverse events in PSC are currently lacking. Recently, serum IgE was found to be associated with CCA in a Japanese cohort of PSC patients. Our aim in this study was to determine whether IgE levels predict time to CCA, liver transplantation, or death in a Western (USA-based) cohort of PSC patients.
MATERIAL AND METHODS: Thirty-eight patients with PSC and IgE levels were identified and categorized into low or high IgE groups based on the sample median. Groups were compared with respect to clinical characteristics and adverse endpoint-free survival, and the association between IgE and endpoints was assessed with multivariate proportional-hazards models.
RESULTS: The median sample age at PSC diagnosis was 41 years, and median serum IgE level was 47.6 kU/L. Low and high IgE groups differed significantly only with respect to IgG subclasses, which were higher among the latter (p < 0.05). There were no significant differences in composite endpoint-free (p = 0.83) or CCA-free survival (p = 0.20). In multivariate analyses, only Mayo PSC risk score and MELD score were significant predictors of endpoint-free survival (p < 0.05).
CONCLUSIONS: Serum IgE level is associated with several IgG subclass levels but not time to CCA, liver transplantation, or death among PSC patients in a USA-based cohort. While Mayo PSC risk score and MELD score can predict these outcomes, more specific predictors of CCA are needed.