Abstracts Poster Abstracts - Dr Falk

28Peripheral blood dendritic cell subsets and serum interleukin-12levels in patients with chronic hepatitis C virus infection: Relationto disease activityH.A. El Aggan 1 , N.M. Farahat 2 , F.S. Mohamed 1 , E.M. Emam 3 , E.F. Gaballah 1Department of Medicine (Hepatobiliary Unit) 1 , Clinical Pathology 2 and Pathology 3 ,Faculty of Medicine, University of Alexandria, EgyptIntroduction: Hepatitis C virus (HCV)-specific T-cell immune responses appear toinfluence the outcome of HCV infection and require activation by antigen presentingcells like dendritic cells (DC). Therefore, the present work was designed to study the DCsubsets (myeloid and lymphoid) in peripheral blood and to assess the serum levels ofinterleukin-12 (IL-12) in patients with chronic hepatitis C in relation to disease activity.Methods: 28 patients with chronic hepatitis C (15 with elevated serum levels of alanineaminotransferase (ALT) and 13 with persistently normal ALT levels) and 12 healthysubjects were included in the study. All patients had seropositivity for anti-HCVantibodies and HCV RNA. The percentages of DC subsets in peripheral blood weredetected using 3-color flow cytometric assay. Dendritic cells were identified as lineagemarker negative (lin-)/HLA-DR positive cells and the differentiation of myeloid DC subsetfrom lymphoid DC subset was based on the expression of CD11c or CD123 on the cellsurface respectively. Quantitative determination of IL-12p70 heterodimer in serum wasperformed using a solid phase sandwich enzyme-linked immunosorbent assay kit.Results: The percentages of peripheral blood DC subsets (CD11c + and CD123 + ), theCD11c + DC/CD123 + DC ratio and the serum IL-12 levels were significantly lower inchronic hepatitis C patients than in healthy subjects and in patients with elevated ALTthan in those with normal ALT (p < 0.05). The reduction in circulating DC subsets andserum IL-12 levels showed negative correlations with serum levels of ALT and thehistopathological grading and staging scores (p < 0.05) but not with serum HCV RNAlevels (p > 0.05). The serum IL-12 levels were positively correlated with the percentagesof peripheral blood CD11c + DC subset (p < 0.05)Discussion/Conclusion: Patients with chronic HCV infection had significantdeficiencies in circulating DC subsets, particularly the myeloid subset and in IL-12production, which were well correlated with disease activity and hepatocellular injury.These findings suggest that DC and IL-12 may play a key role in the progression of liverdisease in chronic HCV infection and may provide a potential new goal for HCVimmunotherapy.