Larisa Denisa Ursu, Carmen Monica Preda, Mircea Diculescu and Ileana Constantinescu
Natural killer (NK) cells play an important role in viral clearance and in the elimination of neoplastic cells. Recent cellular and genetic studies revealed that NK cells modulate the immune response against hepatitis C virus (HCV). Improving our understanding of NK cells could help us gain further insight into the virus-host interaction and the mechanisms of viral persistence. Previous studies mention the role of Killer cell Immunoglobulin-like Receptors (KIRs) and their Human Leukocyte Alleles (HLA) ligands in disease progression of chronic HCV infected patients. Specific HLA class I and class II alleles may influence the susceptibility or resistance to persistent HCV infection. In the last few years, progress has been made in the link between KIR-HLA gene polymorphisms and susceptibility to immune-mediated diseases such as chronic HCV infection. Many studies have shown the importance of NK cells in the outcome of chronic HCV patients. The immune response against HCV is affected by certain KIR genes and HLA genes. There is a great potential for the use of KIR genes as a prognostic tool for the development of complications such as liver cirrhosis and HCC.