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

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.
To investigate whether the killer immunoglobulin-like receptor (KIR) genes were associated with seroconversion in HBeAg positive CHB responder patients treated with ETV.
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).
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).
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.