ObjectivesTo systematically review the efficacy and safety of pegylated interferon α-2a (Peg-IFNα-2a) combined with entecavir (ETV) versus Peg-IFNα-2a alone in treatment of HBeAg-positive chronic hepatitis B (CHB) patients.MethodsThe Cochrane Library, PubMed, Web of Science, EMbase, CNKI, VIP and WanFang Data databases were electronically searched to collect randomized controlled trials (RCTs) on Peg-IFNα-2a combined with ETV for HBeAg-positive CHB from inception to March, 2019. Two reviewers independently screened literature, extracted data and assessed risk of bias of included studies. Then, meta-analysis was performed by using RevMan 5.3 software.ResultsA total of 12 RCTs involving 1 130 patients were included. The results of meta-analysis showed that: compared with Peg-IFNα-2a monotherapy, Peg-IFNα-2a combined with ETV could improve the rate of serum HBV-DNA clearance (RR=2.55, 95%CI 1.83 to 3.55, P<0.000 01), ALT normalization (RR=2.37, 95%CI 1.76 to 3.20, P<0.000 01) and HBeAg seroconversion (RR=2.88, 95%CI 1.18 to 7.03, P=0.02) after 12 weeks of treatment. Additionally, it could improve the rate of serum HBV-DNA clearance (RR=2.10, 95%CI 1.74 to 2.53, P<0.000 01), AST normalization (RR=1.87, 95%CI 1.15 to 3.04, P=0.01), ALT normalization (RR=1.70, 95%CI 1.46 to 1.99, P<0.000 01), serum HBeAg clearance (RR=2.14, 95%CI 1.62 to 2.83, P<0.000 01), HBeAg seroconversion (RR=2.51, 95%CI 1.65 to 3.82, P<0.000 01) and serum HBsAg clearance (RR=2.78, 95%CI 1.06 to 7.31, P=0.04) after 24 weeks of treatment. It could also improve the rate of serum HBV-DNA clearance (RR=1.63, 95%CI 1.32 to 2.02, P<0.000 01), AST normalization (RR=2.75, 95%CI 1.82 to 4.16, P<0.000 01), ALT normalization (RR=1.47, 95%CI 1.33 to 1.63, P<0.000 01), serum HBeAg clearance (RR=1.65, 95%CI 1.42 to 1.91, P<0.000 01), HBeAg seroconversion (RR=1.91, 95%CI 1.51 to 2.41, P<0.000 01) and serum HBsAg clearance (RR=1.57, 95%CI 1.07 to 2.31, P=0.02) after 48 weeks of treatment. There was no statistically significance of adverse reactions in groups.ConclusionsCurrent evidence shows that Peg-IFNα-2a combined with ETV is superior to Peg-IFNα-2a monotherapy in the treatment of HBeAg-positive CHB, and does not increase the incidence of adverse reactions. Due to the limited quality and quantity of the included studies, more high quality studies are required to verify the above conclusion.