本文运用系统评价方式，探讨血清白细胞介素-21(interleukin-21，IL-21)在核苷(酸)类似物(nucleotide analogues，NAs)治疗慢性乙型肝炎(chronic hepatitis B，CHB)患者病毒学应答、乙型肝炎E抗原(hepatitis B E antigen，HBeAg)血清学转换及病毒复发等状态下的水平变化。检索PubMed、Cochrane Library、EMbase、Web of Science、Springer Link、中国知网、中国生物医学文献数据库(China Biology Medicine disc，CBM)、万方数据库、维普系列数据库、独秀数据库等，设置检索时间为2010年01月—2024年11月，依据纳排标准进行文献筛选、数据提取及质量评价，采用Review Manager 5.4软件进行Meta分析。结果显示，HBV DNA完全应答组IL-21水平显著高于HBV DNA不全应答组(RR＝24.94, 95%CI为[20.09, 29.80 ]，Z＝10.07，P＜0.01)；HBeAg转阴组IL-21水平显著高于HBeAg未转阴组(RR＝34.22，95%CI为[29.01, 39.44]，Z＝12.86，P＜0.01)；病毒学持续应答组IL-21显著高于病毒学复发组(RR＝－13.07，95%CI为[－15.51, －10.62]，Z＝10.47，P＜0.01)。血清IL-21可作为评估患者疗效、协助调整抗病毒方案及评估预后的有效生物学标志物。

This study aimed to investigate the changes of serum interleukin-21 (IL-21) levels in patients with chronic hepatitis B (CHB) under the conditions of virological response, hepatitis B E antigen (HBeAg) seroconversion and viral relapse after treatment with nucleoside (acid) analogues (NAs). It searched PubMed, Cochrane Library, Embase, Web of Science, Springer Link, CNKI, CBM, Wanfang, WIP, Duxiu, and other databases from January 2010 to October 2024. Literature screening, data extraction and quality evaluation were carried out according to the inclusion criteria, and Meta-analysis was conducted by Review Manager 5.4 software. The level of IL-21 in HBV DNA complete response group was significantly higher than that in HBV DNA incomplete response group (RR ＝ 24.94, 95% CI [20.09, 29.80 ], Z ＝ 10.07, P<0.01), and the level of IL-21 in HBeAg negative group was significantly higher than that in HBeAg positive group (RR ＝ 34.22, 95% CI [29.01, 39.44]，Z＝12.86，P＜0.01), IL-21 was significantly higher in the virological sustained response group than in the virological relapse group (RR ＝－13.07, 95% CI [－15.51, －10.62], Z＝10.47, P<0.01). Serum IL-21 can be used as an effective biomarker to evaluate the therapeutic effect of patients, to assist in the adjustment of antiviral therapy and to evaluate the prognosis of patients.