الفهرس 
Hepatitis C VirusOnly 14 pages are availabe for public view
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Abstract
I
mpaired activity of natural killer (NK) cells has been proposed as a mechanism contributing to viral persistence in hepatitis C virus (HCV) infection. The function of NK cells is regulated by a group of activating and inhibitory receptors, including the natural cytotoxicity receptors (NCRs) and NKG2D on NK cells. Some T cells also express NK receptors (NKRs) and mediate functions of both T cells and NK cells. Altered expression of these receptors is likely to result in altered functions of NK cells and CD8+cells. The aim of the present study was to investigate whether NKG2D expression on NK cells is dysregulated in hepatitis C patients in comparison to healthy controls.
A total of 60 subjects were included in the study, 40 patients with chronic hepatitis C (patients’ group) and 20 healthy individuals (control group). All patients underwent full history taking and clinical examination, pelvi-abdominal ultrasonography, testing for liver function tests, HBsAg, HCV Ab by ELISA and HCV RNA by Real Time-PCR. Healthy controls were included based on testing normal for liver function tests and negative for the above mentioned serologic viral markers. All individuals were subjected to flow cytometric assessment of NKG2D expression on NK cells and on T lymphocytes.
The expression of NKG2D on NK cells and on T lymphocytes demonstrated significant change in values in HCV patients (patient group) compared to healthy individuals (control group) where patients showed reduced expression of NKG2D on both cells. Results, however, were comparable among the viremia subgroups as regard NKG2D expression on NK cells and on T lymphocytes.
This study showed also highly significant positive correlation between NKG2D expression on NK cells and T lymphocytes. Correlation studies of the two cell populations investigated versus different laboratory parameters among patients’ group revealed statistically significant negative correlation between NKG2D+NK cells and serum direct bilirubin. Meanwhile, serum albumin has shown significant positive correlation to NKG2D+ T cells.
In Conclusion: Significant differences were obtained between patient and control groups as regards NK cells as well as T lymphocytes expressing NKG2D receptors with patients’ group having lower levels than controls. These results are suggestive of a possible impact of this receptor on mounting an effective immune response against HCV infection which may aid in providing future therapeutic modalities to help eradicating infection and preventing disease progression.