Neutrophils play an immune defense role by releasing the proteases such as neutrophil elastase and myeloperoxidase to form neutrophil extracellular trap （NET） and participate in the inflammatory response of various liver diseases， but the excessive release of NET may worsen liver tissue damage and has thus become one of the risk factors for liver diseases. In recent years， studies have shown that the excessive release of NET can promote the progression of liver diseases （such as viral hepatitis， nonalcoholic steatohepatitis， and hepatic ischemia-reperfusion injury） to liver cancer， and clarifying the mechanism of action of NET is of great importance for the diagnosis and progression of liver diseases. Therefore， this article elaborates on the latest research advances in NET in liver diseases， so as to provide new insights into the diagnosis and treatment of liver diseases and the prevention of liver cancer.

Objective To investigate the expression of neutrophil extracellular traps (NETs) and phagocytic function in the peripheral blood of patients with hepatic alveolar echinococcosis (HAE), and to examine their correlations with clinical inflamma tory indicators and liver functions. Methods A total of 50 patients with HAE admitted to Department of Hepatobiliary and Pancreatic Surgery, The Affiliated Hospital of Qinghai University from August 2022 to June 2023 were enrolled, while 50 age- and gender-matched healthy individuals from the Centre for Healthy Examinations of the hospital during the same period served as controls. The levels of NETs markers neutrophil myeloperoxidase (MPO) and neutrophil elastase (NE) were measured using enzyme-linked immunosorbent assay (ELISA). Peripheral blood neutrophils were isolated using density gradient centrifugation, stimulated in vitro using phorbol 12-myristate 13 acetate (PMA), and the levels of MPO and citrullination histone H3 (CitH3) released by neutrophils were quantified using flow cytometry. The phagocytic functions of neutrophils were examined using flow cytometry. In addition, the correlations of MPO and NE levels with clinical inflammatory indicators and liver biochemical indicators were examined using Spearman correlation analysis among HAE patients. Results The peripheral blood plasma MPO［(417.15 ± 76.08) ng/mL vs. (255.70 ± 80.84) ng/mL; t = 10.28, P < 0.05］, NE［(23.16 ± 6.75) ng/mL vs. (11.92 ± 3.17) ng/mL; t = 10.65, P < 0.05］and CitH3 levels［(33.93 ± 18.93) ng/mL vs. (19.52 ± 13.89) ng/mL; t = 4.34, P < 0.05］were all significantly higher among HAE patients than among healthy controls, and a lower phagocytosis rate of neutrophils was detected among HAE patients than among healthy controls［(70.85 ± 7.32)% vs. (94.04 ± 3.90)%; t = 20.18, P < 0.05］, and the ability to produce NETs by neutrophils was higher among HAE patients than among healthy controls following in vitro PMA stimulation. Pearson correlation analysis showed that the phagocytosis rate of neutrophils correlated negatively with platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), interleukin-6 (IL-6) level and C-reactive protein (CRP) level (r_s = −0.515 to −0.392, all P values < 0.05), and the MPO and NE levels positively correlated with inflammatory markers NLR, PLR, CRP and IL-6 (r_s = 0.333 to 0.445, all P values < 0.05) and clinical liver biochemical indicators aspartic transaminase, alanine aminotransferase, direct bilirubin and total bilirubin among HAE patients (r_s = 0.290 to 0.628, all P values < 0.001). Conclusions Excessive formation of NETs is found among HAE patients, which affects the phagocytic ability of neutrophils and results in elevated levels of inflammatory indicators. NETs markers may be promising novel biomarkers for early diagnosis, monitoring, and severity assessment of liver disease.