[Identification of phenotype and Interferon-alpha-producing capability of circulating type II dendritic cells and its clinical implication in HBV-infected patients].

Objective: To investigate the number, phenotype, and interferon-alpha (INF-alpha) of type II dendritic cells (DC2) in persons with hepatitis B and evaluate the role of DC2 subset in the immunopathogenesis of chronic HBV infection.

Methods: Peripheral blood was extracted from 103 hepatitis B (HB) virus-infected persons, including 11 cases of HB virus (HBV)-infected persons, 11 cases of acute HB, 81 cases of chronic HB, and 11 cases of asymptomatic HBV infection, and 25 healthy blood donors used as controls. Flow cytometry was used to calculate the number and the phenotype of circulating DC2. Ultraviolet-inactivated herpes simplex virus (HSV)-1 was added into the suspension of peripheral blood mononuclear cells (PBMCs) and then co-cultured for 24 hours to stimulate the production of INF-alpha by DC2 that was examined by ELISA assay.

Results: The number of DC2 in patients with chronic HB was 3.3 +/- 1.0 10(6)/L, significantly lower than that in the healthy controls (7.2 +/- 2.4 10(6)/L, P < 0.01). However, the number of DC2 was not significantly different between any other groups. The proportion of GS2 to PBMCs in the patients with chronic HB was 1.12 +/- 1.13 approximately 0.22 +/- 0.10, all significantly lower than that in the healthy controls (0.32% +/- 0.13%, P < 0.01). However, the proportion of GS2 to PBMCs was not significantly different between any other groups. The decrease of number of DC2 and that of proportion of DC2 to PBMCs in patients with chronic HB were related with the progress of disease. The INF-alpha concentration in the suspensions of PBMCs of different groups without stimulation by HSV-1 were low and there was no significant difference in INF-alpha concentration between different groups. The INF-alpha concentration in the suspension of PBMCs of healthy controls was 789 +/- 82 pg/ml, significantly higher than those of the patients with acute HB (161 +/- 36 pg/ml) and the patients with chronic HB (183 +/- 113 pg/ml, 147 +/- 39 pg/ml, and 156 +/- 39 pg/ml, all P < 0.05). However, there was no significant difference between the patient groups (all P > 0.05).

Conclusion: The number and INF-alpha producing function of DC2, and the numbers of NK cells and CD8+ T cells in peripheral blood of patients with chronic HB decrease significantly, which results the deficiency of HBV-specific immune response.