Source Department of Clinical Immunological Laboratory, West China Hospital, Sichuan University, Chengdu, China Department of Nephrology, West China Hospital, Sichuan University, Chengdu, China Department of Clinical molecular Laboratory, West China Hospital, Sichuan University, Chengdu, China.
Interleukin-18 (IL-18) is a potent proinflammatory cytokine, which can promote hepatitis B virus clearance. The latest studies find that genetic polymorphisms near the IL-28B gene are strongly associated with sustained viral response and spontaneous viral clearance in patients with chronically infected hepatitis C and hepatitis B.
We investigated the effect of rs187238 and rs1946518 in IL-18 gene and rs8099917 in IL-28B gene on HBV recurrence in liver transplant patients. A total of 200 liver transplant recipients and relevant donors were enrolled in this study. The patients' mean follow-up was 39 month (range 10-65 month). All liver transplant recipients were in a stable stage. The total recipients (n = 200) were divided into end-stage liver disease secondary to hepatitis B (n = 140) and end-stage liver disease secondary to other diseases (n = 60) before transplantation. Recipients (n = 140) with hepatitis B before transplantation were defined to nonHBV recurrence group (n = 119) or HBV recurrence group (n = 21), which was positive for HBsAg or elevatory in HBV DNA (>2.0 × 10(2) IU mL(-1) ) after transplantation. For the recipients (n = 140) had hepatitis B before transplantation, we studied the single-nucleotide polymorphisms (SNPs) of IL-18 gene (rs187238 and rs1946518) and IL-28B gene (rs8099917) by high-resolution melting (HRM) curve analysis. The serum levels of IL-18 and IFN-γ were tested by ELISA. The serums levels of IFN-γ were lower in HBV recurrence group than that in nonHBV recurrence group (P < 0.01). The genotype of IL-28B gene rs8099917 was associated with alanine aminotransferase (ALT) levels and aspartate aminotransferase (AST) levels in HBV-related liver transplant recipients (n = 140). The recipients with allele G (GG+GT) had higher ALT and AST levels (P < 0.05).
No association was found between IL-18 gene and IL-28B gene polymorphisms with HBV recurrence in the liver transplant recipients or the donors. We identified that the IFN-γ was a protective factor of HBV recurrence after liver transplantation. The allele G of rs8099917 was associated with hepatitis B-related hepatocytes injury. The rs8099917 G allele subgroup should reinforce antiviral therapy.