Abstract: Objective To investigate the relationship between the count of peripheral blood dendritic cells(DCs) and clinical outcome in patients with acute-on-chronic hepatitis B liver failure(ACHBLF).Methods This study included 70 patients with ACHBLF admitted to our hospital from June 2010 to September 2014.These patients were divided into survival group and death group according to their clinical outcomes at 3 months.Multivariatelogistic regression analysis was used to determine the clinical indices as prognostic factors.Flow cytometry was used to measure the number(107) and percentage(%) of subsets of DCs in peripheral blood.Comparison of DCs between the two groups was made by two-independent-samples t test or rank sum test,and linear correlation and multivariate regression analysis was performed to determine whether DCs could be used as an independent predictor of the clinical outcome of ACHBLF.Results Total bilirubin(TBil) was a clinical prognostic factor for ACHBLF at 3 months(OR = 1.008,95% CI: 1.003-1.014,P = 0.003).The number of myeloid DCs(m DCs) in peripheral blood was significantly higher in the survival group than in the death group [(7.3 ± 6.2) × 107vs(4.1 ± 4.0) × 107,t =2.336,P <0.05],and the number of plasmacytoid DCs(p DCs) in peripheral blood was also significantly higher in the survival group than in the death group [(0.8 ± 0.6) × 107vs(0.4 ± 0.5) × 107,t =2.307,P <0.05).There were no significant differences in the percentages of m DCs and p DCs between the two groups(Z =-0.080,P > 0.05; t =-0.248,P > 0.05).The numbers of m DCs and p DCs showed no linear relationship with TBil(R2= 0.009 and 0.059,respectively).The numbers of m DCs and p DCs could be included in the multivariate regression equation,and the results showed that m DCs(OR = 0.789,95% CI: 0.665-0.935,P = 0.006) and TBil(OR = 1.013,95% CI: 1.006-1.020,P < 0.001) were independent prognostic predictors for ACHBLF.Conclusion The numbers of m DCs and p DCs in peripheral blood are higher in surviving patients with ACHBLF than in those who die,and the number of m DCs is an independent prognostic predictor.The number of DCs may be an influencing factor for the clinical outcome of patients with ACHBLF.