ObjectiveTo investigate the relationship between changes in serum cytokine levels at 72 h after artificial liver therapy (plasma exchange, PE) and clinical prognosis in patients with liver failure. MethodsFifty-eight patients with liver failure, who received PE in Department of Infectious Diseases, The No. 2 People′s Hospital of Lanzhou from April 2011 to April 2012, were included in the investigation; they were divided into improved group and uncured group according to their treatment outcomes. The serum interleukin (IL)-4, IL-6, IL-10, tumor necrosis factor (TNF)α, and interferon (IFN)γ levels before and 72 h after therapy were measured, and the relationship between the changes in these indices and prognosis was observed. The data were expressed in the form of mean ± standard deviation. The baseline values and values after therapy were compared by paired t-test, and the differences between two groups were determined by the t-test for comparison between groups. ResultsAfter PE therapy, 67.24% of all patients (39/58) showed an improvement, while 32.75% (19/58) were not cured. At 72 h after therapy, the improved group had significant changes in serum IL-4, IL-6, IL-10, TNFα, and IFNγ levels (t=2.048-5.163, P＜0.05), and had more decrease in serum IL-4, IL-6, TNFα, and IFNγ and more increase in serum IL-10 level compared with the uncured group. Before therapy, the serum IL-6 and TNFα levels were significantly higher in the uncured group than in the improved group (t=2.024-2.174, P＜0.05). ConclusionArtificial liver therapy can decrease TNFα, IL-4, IL-6, and IFNγ and increase IL-10 in serum and thus is an effective treatment for liver failure. It seems that IL-6 and TNFα play a more important role than other cytokines in immune injury in patients with liver failure.