OBJECTIVETo evaluate the efficacy and safety of pegylated interferon alpha 2a (PEG-IFN alpha-2a) in treating patients with chronic hepatitis B.

METHODSeventy-two patients with chronic hepatitis B were assigned to a PEG-IFN alpha-2a (experimental) group (n=42) and an interferon alpha (control) group (n=30) randomly. Each patient in the experimental group received 180 microg PEG-IFN alpha-2a every week. Each patient in the control group received 500 MU interferon alpha every day. All the patients were treated for 48 weeks, and then were followed for another 48 weeks with no treatment.

RESULTSAt the end of the 12th week, the rate of HBeAg negative cases was 30% in the PEG-IFN alpha-2a group, which was much higher than in the control group (x2 = 4.162, P < 0.05). The values of HBeAg and the log value of HBV DNA in the PEG-IFN alpha-2a group were much lower than the values before the treatment (t = 2.689, t = 4.080, P <0.01), but there was no difference between before and after treatment in the control group ( t = 1.229, t = 1.009, P > 0.05). At the end of the 24th week, the rate of HBeAg negative cases in the PEG-IFN alpha-2a group was much higher than that in the control group (x2=6.190, P < 0.05). The value of HBeAg and the log value of HBV DNA in the PEG-IFN alpha-2a group were much lower than in the control group (t=2.215, t=2.122, P < 0.05). At the end of the 48th week, besides the reduction mentioned above, the rate of cases with HBeAg/antiHBe seroconversion and normalization of ALT and complete responsiveness in the PEG-IFN alpha-2a group were all much higher than those in the control group (x2=5.771, x2=5.617, x2=5.308, P < 0.05). At the end of 48 weeks with no treatment, all the parameters mentioned above in the PEG-IFN alpha-2a group were much better than those in the control group and they remained so, but they were different in the control group (x2=11.943, t=3.439, t=6.111, x2=9.930, x2=9.522, x2=7.920, P < 0.01). Nine patients in the PEG-IFN alpha-2a group had liver biopsies before their treatment and also at the end of their treatment. The expressions of HBsAg and HBcAg were decreased at the end of the treatment. The rate of expression of HBsAg in the liver tissues before the treatment was 88.9% but only 22.2% at the end of the treatment (x2=8.001, P < 0.01). The rate of expression of HBcAg in the livers before treatment was 66.7% but only 33.3% at the end of the treatment. Before and at the end of the PEG-IFN alpha-2a treatment, there were no significant changes in the degrees of inflammation and fibrosis and the quantity of collagen in the liver tissues. Three patients in the PEG-IFN alpha-2a group (10%) were HbsAg negative. Two of them were found so at the end of 32 weeks with treatment and one patient was found at the end of 24 weeks with no treatment, but there were no HBsAg negative patients in the control group. The adverse reactions that occurred in the PEG-IFN alpha-2a and in the control groups were similar.

CONCLUSIONPEG-IFN alpha-2a was effective in inhibiting HBV replication. The effect of PEG-IFN alpha-2a was lasting. PEG-IFN alpha-2a was well tolerated during our treatment.