Study of natural killer and natural killer T cells in chronic hepatitis C infection

ABSTRACT

Natural killer [NK] and natural killer T [NKT] cells are components of the innate immune system, and participate in the inflammatory processes during hepatic diseases. Impaired activity of these cells is suggested to contribute to viral persistence and chronic infection in hepatitis C virus [HCV] infection. However, the exact mechanisms are not yet fully understood. To investigate the frequency of peripheral NK and NKT cells in patients with chronic HCV infection, as compared with healthy controls. Thirty patients with chronic hepatitis due to HCV infection were included. Patients with liver cirrhosis, HCV and hepatitis B virus co-infection, diabetes mellitus, or who received interferon therapy were excluded. In addition, 20 normal healthy individuals were included as controls. Assessment of the frequency of peripheral NK and NKT cells by flow cytometry was carried out for all individuals. Compared with controls, patients with HCV had significantly lower percentages of NK and NKT cells in peripheral blood. Among patients with HCV, NK and NKT cell percentages did not correlate significantly with serum transaminase levels. Defective innate immunity, as evidenced by reduced peripheral NK and NKT cell frequency, is observed in patients with chronic hepatitis C infection