Enhanced levels of interleukin-8 are associated with hepatitis B virus infection and resistance to interferon-alpha therapy

Abstract

The objective of this study was to analyze the expression levels of IL-8 in serum and liver tissues from patients with chronic hepatitis B (CHB) infection and to investigate whether IL-8 may antagonize interferon-alpha (IFN-α) antiviral activity against HBV. IL-8 expression in serum was determined by enzyme linked immunosorbent assay (ELISA), and fluorescence-based quantitative real-time PCR (RT-qPCR) was used to measure IL-8 mRNA in peripheral blood mononuclear cells (PBMCs) in patients with CHB. IL-8 protein expression was detected in liver biopsy tissues by immunohistochemistry. In addition, the differences in serum IL-8 and PBMCs mRNA levels were also observed in patients with different anti-viral responses to IFN-α. Compared to normal controls, serum IL-8 protein and mRNA levels were increased in CHB patients, IL-8 levels were positively correlated with the severity of liver inflammation/fibrosis. Moreover, serum IL-8 protein and mRNA levels were positively correlated with serum alanine aminotransferase (ALT) level and negatively correlated with serum prealbumin (PA) level. IL-8 expression was mainly located in portal area of liver tissues and was increased with the severity of liver inflammation and fibrosis stage. The expression serum and mRNA levels of IL-8 in the CHB patients with a complete response to IFN-α are significantly lower than that of the patients with non-response to IFN-α treatment. It is suggested that IL-8 might play important roles in the pathogenesis of CHB. Moreover, interferon resistance may be related to the up-regulation of IL-8 expression in the patients did not respond to IFN-α treatment.