Elevated serum IL-18 and interferon-gamma in medium-term survivors of biliary atresia

Abstract

Introduction Biliary atresia (BA) is a fatal disease in children. Its main pathological feature is progressive immune-mediated cholangiopathy. Interleukin (IL)-12, IL-18, and interferon-gamma (IFN-gamma) play important roles in various immunological diseases. The objective was to investigate whether these serum markers were associated with clinical outcome in BA. Methods Serum levels of IL-12, IL-18, and IFN-gamma were determined using enzyme-linked immunosorbent assay from 46 BA patients (median age of 9 years) and 19 normal controls. The BA patients were then categorized into three groups according to their outcome: jaundice-free (29 cases), mild to moderate jaundice (10 cases), and marked jaundice (7 cases). The comparisons of serum IL-12, IL-18, and IFN-gamma levels among groups of the patients were performed using one-way analysis of variance with post-hoc tests. Data are expressed as mean + standard deviation. Results Serum IL-18 and IFN-gamma in BA patients were higher than the normal controls (IL-18: 113.3 + 82.6 vs. 80.5 + 9.9 pg/mL, p = 0.011 and IFN-gamma: 41.7 + 5.1 vs. 38.0 + 1.9 pg/mL, p < 0.001). There was no difference in serum IL-12 between BA and controls. Further analysis demonstrated that, in BA patients, only serum IL-18 levels significantly increased with the degree of jaundice (test for trend, p = 0.004). Conclusions Serum IL-18 and IFN-gamma levels were increased in medium-term survivors of BA. The elevated serum IL-18 in BA patients was associated with worse clinical outcome. These results suggest that IL-18 and IFN-gamma play roles in the pathophysiology of BA. Additionally, IL-18 is likely to be involved in the disease progression. Copyright © 2012 by Thieme Medical Publishers, Inc.