Association between KIR Genes and Efficacy of Treatment of HBeAg-Positive Chronic Hepatitis B Patients with Entecavir

Background: Entecavir (ETV) is commonly used to treat chronic hepatitis B (CHB) in China. However, certain percentages of e-Antigen (HBeAg) positive CHB patients do not respond to ETV therapy. Objective: To investigate whether the killer immunoglobulin-like receptor (KIR) genes were associated with seroconversion in HBeAg positive CHB responder patients treated with ETV. Methods: Polymerase chain reaction with sequence-specific primers (PCR-SSP) method was performed to genotype KIR genes in 200 healthy controls and 198 HBeAg-positive CHB patients which 59 were defined as the complete response group (CRG) to the treatment with ETV and 139 were defined as null or partial response group (NPRG). Results: The frequencies of KIR2DS2 and KIR2DS3 were significantly higher (P=0.030, OR=1.57，95%CI=2.36- 1.05 and P=0.018, OR=1.773，95%CI=2.77-1.13, respectively), while, the frequencies of KIR2DL3, KIR2DS1 and KIR3DS1 were significantly lower (P=0.038, OR=0.525, 95%CI=0.96-0.29,and P=0.031, OR=0.640, 95%CI =0.95-0.43, and P=0.035, OR=0.641, 95%CI =0.96-0.43, respectively) in HBeAg-positive CHB patients than those in healthy controls. The frequency of KIR2DS3 gene was significantly higher in NPRG than that in CRG (P=0.018, OR=0.402, 95%CI=0.83-0.20). The frequencies of KIR2DL3 and KIR3DS1 genes were significantly higher in CRG than those in NPRG (P=0.019, OR=3.625, 95%CI=10.83-1.21 and P=0.041, OR=1.949, 95%CI=3.65-1.04, respectively). Conclusion: Patients with KIR2DS3 might have negative responses to anti-HBV therapy with ETV and patients with KIR2DL3 and KIR3DS1 might have advantage in the therapy with ETV.