中文摘要：

白细胞介素21 （IL-21）是一种主要由活化的CD4＋T淋巴细胞和自然杀伤T淋巴细胞分泌且具有多效性的细胞因子,广泛参与固有免疫和适应性免疫的应答过程.近来研究表明,IL-21在HBV感染过程中能够促进机体多种免疫细胞功能活化,IL-21基因多态性与HBV易感性相关.此外,IL-21表达与HBV基因型、HBV的清除、HBeAg血清学转换、HBV相关的肝硬化、肝衰竭、肝癌及自身免疫性疾病等密切相关.现结合上述内容和IL-21相关临床试验方面的进展进行综述.

英文摘要：

Interleukin-21 （IL-21） is a cytokine mainly secreted by activated CD4＋ T cells and natural killer T cells and has multiple effects.It is involved in innate and adaptive immune responses.Recent studies have shown that IL-21 can promote functional activation of various immune cells in the process of hepatitis B virus （HBV） infection,and the gene polymorphisms of IL-21 is associated with the susceptibility to HBV.In addition,the expression of IL-21 is closely associated with HV genotype,HBV clearance,HBeAg seroconversion,HBV-related liver cirrhosis,liver failure,liver cancer,and autoimmune disease.This article reviews the research advances in clinical trials with reference to the aspects above.