Frequency of killer cell immunoglobulin-like receptors (KIRs) in Korean patients with chronic HCV infection.

Natural killer (NK) cells play an important role in innate immunity, especially in the response to viral infections, such as hepatitis C virus (HCV). Killer cell immunoglobulin-like receptors (KIRs) are the primary receptors of NK cells that mediate innate immunity. KIRs are also involved in acquired immunity, because some KIRs are expressed on the surface of certain subsets of T cells. In this study, the frequency of KIR genes, HLA-C allotypes, and combinations of KIR genes with their HLA-C ligands were evaluated in two different groups of the Korean population: controls and patients with chronic HCV infection. The study population consisted of 147 Korean patients with chronic HCV infection. The frequency of KIR2DS2 in patients with chronic HCV infection was 9.5% which was significantly lower than 19.5% of the control (P < 0.01). However, there were no significant differences in the frequency of other KIR genes, HLA-C allotypes or different combinations of KIR genes with their HLA-C ligands. This study can contribute to the further prospective study with a larger scale, suggesting the assumption that KIR2DS2 might aid in HCV clearance by enhancing both the innate and acquired immune responses of people in Korea.