Natural Killer T cells in Egyptian Patients with HCV-associated Non-alcoholic Fatty Liver Disease

Abstract

Background:Studies on Natural Killer T (NKT) cells in Non-alcoholic fatty liver disease (NAFLD) have shown contradictory results. Moreover, the effect of HCV superinfection on NKT cells in NAFLD patients have not been previously studied. Aim: to assess the effect of the concomitant HCV infection on the frequency of NKT cells and CD8+ T cells in a cohort of Egyptian patients with hepatic steatosis. Subjects and Methods: Two-hundred subjects were divided into four equal groups, 1) concomitant hepatic steatosis/HCV, 2) HCV (without steatosis), 3) steatosis (without HCV), and 4) normal controls. NKT and CD8+ T cells were identified by monoclonal antibodies surface staining for (CD3, CD56, CD161), and (CD3, CD8) respectively using flow cytometry. Results: CD3+/CD56+/CD161+ NKT cells were significantly higher in patients with either steatosis (alone) or concomitant HCV/steatosis compared to control (p<0.0001 each), while comparable NKT frequency was found between HCV group and control (p=0.72). A significant increase in CD3+/CD8+ T cells was noted in the three patients’ groups compared to control (p=0.0001, 0.002 and 0.001, respectively). Interestingly, NKT cells were significantly higher in patients with steatosis/HCV compared to those with HCV alone (p<0.0001), while, they did not differ betweenconcomitant HCV/steatosis and steatosis (alone) group. Higher frequencies of both NKT cells and CD8+ T cells were significantly associated with increased severity of steatosis. In HCV group, NKT frequencies were unrelated to steatosis severity. Conclusion: NKT cells are significantly elevated in patients with hepatic steatosis irrespective to the presence or absence of concomitant HCV infection.