الفهرس 
Introduction and aim of the workOnly 14 pages are availabe for public view
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Abstract
Introduction: One important clinical feature of HCV infection is the high frequency of chronicity. The capacity of hepatitis C virus (HCV) infected individuals to induce a wide spectrum of CTL response during the early stages of infection is probably the most critical factor to control hetreogenous infection viral quasispecies. Aim of work: The aim of this work was to study the role of cell mediated immunity in chronic HCV patients, aiming to declare their rule in the pathogenesis and development of chronicity in these patients. Methods: We selected 35 patients with mean age 38.9 7.8 years old having chronic liver disease due to HCV and fifteen apparently healthy subjects of matched age were taken as a control group. Both groups underwent: full history taking, complete clinical examination and investigations including: routine urine and stool analysis, C.B.C, serum creatinine, fasting and post prandial blood sugar, HBsAg, antiHCV, RTPCR for HCV. Liver biochemical tests (serum bilirubin, ALT, AST, serum albumin, ALP, and prothrombin time). Determination of CD3, CD4 and CD8 in peripheral blood, and concentration of IL10 and IL12 in sera. Results: Our study showed non significant change in the percentage of CD3+ cells in chronic hepatitis C virus patients compared to the control group, while percentage of CD4 Thelper lymphocytes were significantly decreased. This may be associated with a decrease in IFN production, the cytokine with an important antiviral effect. A state of immune suppression will result. Our work also revealed significant increase in percentage of CD8+ cells. We suggest that there is dysfunction of CD8+ T cells inspite of increased their number. We also found significant increase in the concentration of both IL12 and IL10 in patients vs control. There is imbalance in the production of these cytokines in patients with chronic HCV infection. We could speculate that IL10 produced by activated Th2 to control the inflammatory changes in the liver leads to inhibition of Th1 type cells and macrophages and their cytokines production of IFN and IL12. Both cytokines are very important in the defense mechanism against viral infection. Our study also revealed an increased serum level of IL12 in patient with chronic HCV infection. This increase in IL12 is either insufficient to stimulate Th1 and cytotoxic T lymphocytes (CTL) cells to be capable of eliminating viral infected cells or there is diminished Th1 response leading to decrease IFN? production. This may have a role in persistence and chronicity of HCV. Conclusion: It is concluded that changes in cell mediated immunity are present in chronic HCV patients. T helper (CD4) cells, the cells that promote other immune system cells are decreased with possible shift from Th1 to Th2 cells. CTLs (CD8) cell that kill viral infected cells are increased in percentage but their functions are most propably impaired. IL10 and IL12 cytokines were found to be increased. We suggest that these changes may be responsible to some extent for HCV chronicity