Th1/Th2 Cells and Associated Cytokines in Acute Hepatitis E and Related Acute Liver Failure

Abstract

Background and Aims. The involvement of cellular immunity in the development of hepatitis E virus (HEV) infection is rare. We aimed to study the roles of viral load and Th cell responses in acute hepatitis E (AHE) and HEV-related acute liver failure (HEV-ALF). Methods. We evaluated viral load and Th1/Th2 cytokine levels in 34 patients with HEV infection, including 17 each with AHE or HEV-ALF. Seventeen healthy controls (HCs) were also included who were negative for anti-HEV IgM and IgG. Results. There was no significant difference in viral load and HEV RNA in the AHE and HEV-ALF groups (both $P>0.05$ ). The Th lymphocyte levels (CD3+, CD4+) in the AHE and HEV-ALF groups were significantly higher than those in the HC group (both $P<0.05$ ), but there was no significant difference between the AHE and HEV-ALF groups ( $P>0.05$ ). Both IFN-γ and IL-10 showed gradual upward trend from the HC group to the AHE (both $P<0.01$ ), but IFN-γ showed a sharp downward trend from the AHE group to the HEV-ALF group ( $P<0.01$ ) and IL-4 showed gradual upward trend from the AHE group to the HEV-ALF group ( $P<0.01$ ).There was no significant difference in Th1 and Th2 cytokines between the HEV RNA(+) group and HEV RNA(-) group (all $P>0.05$ ). Th2 bias was observed from the AHE ( $\text{ratio}=58.65$ ) to HEV-ALF ( $\text{ratio}=1.20$ ) groups. The level of IFN-γ was associated with the outcome of HEV-ALF patients. Conclusions. HEV viral load was not associated with aggravation of AHE, and the HEV-ALF patients showed significant Th2 bias, which may be involved in the aggravation of AHE.