RESUMO
<p><b>OBJECTIVE</b>To investigate the characteristics of circulating type II pre-dendritic cells (pDC2) and evaluate its role in patients with chronic hepatitis B virus infection.</p><p><b>METHODS</b>The quantitative alterations of pDC2 in 27 chronic HBV-infected patients as treated group and 15 healthy individuals as a control group were analyzed by using flow cytometry based on the comparison of CD4+/CD8+ ratios of T lymphocyte subsets between the two groups. The IFN-alpha-producing ability of pDC2 after incubation was determined by ELISA.</p><p><b>RESULTS</b>The percentage of pDC2 (0.096 +/- 0.086) from the peripheral blood in chronic HBV-infected patients were significantly lower than that (0.304 +/- 0.093) from the normal controls (P less than 0.001) while the CD4+/CD8+ ratios were higher than those in normal controls (P less than 0.01). The values of IFN-alpha-producing function and IL-12 of circulating pDC2 in chronic HBV-infected patients group were significantly lower than those in healthy subjects (P < 0.001). The percentage of pDC2 and CD4+/CD8+ ratios were higher in the patients positive for HBV DNA in sera than those in patients negative for HBV DNA in sera (P < 0.01).</p><p><b>CONCLUSION</b>The decreased number of circulating pDC2 and IFN-alpha-producing function from peripheral blood in patients with chronic hepatitis B virus infection may result in the decline of host immune response, which may partially contribute to the disease progress of HBV infection and existence of viral genomic DNA in patient's sera.</p>