Objective: To explore the significance of activation-induced cell death (AICD) in pathogenesis of hepatitis B.
Methods: Peripheral blood mononuclear cells (PBMCs) were isolated from 10 healthy blood donors. PBMCs from one person were divided into two samples. One sample was incubated with the HBV-DNA positive serum. The other was incubated with the serum of healthy person (HBV-DNA negative serum). After 72 hours incubation, the apoptosis of the PBMCs was assayed by the method of propidium iodide (PI) staining with flow cytometry. PBMCs were isolated from 14 patients with chronic hepatitis B, 6 patients with chronic severe hepatitis B and 10 healthy blood donors. The PBMCs were incubated with PHA-P. After 72 hours incubation, the apoptosis of the PBMCs was assayed by the method of PI staining with flow cytometry.
Results: The apoptotic rate of PBMCs incubated with HBV-positive serum was significantly higher than that with the serum of normal persons [(39.56 +/- 7.03)% vs (27.57 +/- 7.78)%, P < 0.02]. The apoptotic rate of PBMCs of patients with chronic hepatitis B (30.57 +/- 13.43%) was significantly higher than that of healthy blood donors [(11.45 +/- 5.27)%, P < 0.01] and higher than that of the patients with chronic severe hepatitis B [(13.59 +/- 6.44)%, P < 0.01].
Conclusion: HBV infection induces apoptosis of PBMC. AICD may be one of the important mechanisms of peripheral immune tolerance in HBV chronic infection.