Natural killer cell receptor variants and chronic hepatitis B virus infection in the Vietnamese population.

• Variations in natural killer cell receptors affect the risk of hepatitis B virus (HBV) and clinical outcomes. • Variation in KIR2DS4 is associated with a risk to chronic HBV. • Combinations of killer-cell immunoglobulin-like receptor (KIR) and human leukocyte antigen (HLA) ligands protect from chronic HBV and liver cirrhosis. • Activating KIR protects HBV patients from hepatocellular carcinoma. Genes of host immunity play an important role in disease pathogenesis and are determinants of clinical courses of infections, including hepatitis B virus (HBV). Killer-cell immunoglobulin-like receptor (KIR), expressed on the surface of natural killer cells (NK), regulate NK cell cytotoxicity by interacting with human leukocyte antigen (HLA) class I molecules and are candidates for influencing the course of HBV. This study evaluated whether variations in KIR gene content and HLA-C ligands are associated with HBV and with the development of liver cirrhosis and hepatocellular carcinoma. A Vietnamese study cohort (HBV n = 511; controls n = 140) was genotyped using multiplex sequence-specific polymerase chain reaction (PCR-SSP) followed by melting curve analysis. The presence of the functional allelic group of KIR2DS4 was associated with an increased risk of chronic HBV (OR = 1.86, pcorr = 0.02), while KIR2DL2+HLA-C1 (OR = 0.62, pcorr = 0.04) and KIR2DL3+HLA-C1 (OR = 0.48, pcorr = 0.04) were associated with a decreased risk. The pair KIR2DL3+HLA-C1 was associated with liver cirrhosis (OR = 0.40, pcorr = 0.01). The presence of five or more activating KIR variants was associated with hepatocellular carcinoma (OR = 0.53, pcorr = 0.04). KIR gene content variation and combinations KIR-HLA influence the outcome of HBV infection. [ABSTRACT FROM AUTHOR]