肺炎克雷伯菌肝脓肿继发血流感染患者NK细胞免疫表型与功能特征研究OA

To analyze the immunophenotypic and functional characteristics of natural killer(NK)cells in the peripheral blood of patients with secondary bloodstream infection of Klebsiella pneumoniae liver abscess(KPLABSI),and to explore the role of NK cells in the immune response to infection as well as the impact of diabetes mellitus on NK cells,this study included 18 patients diagnosed with KPLABSI at Peking University Third Hospital during the period October 2022 to May 2024.Blood samples and clinical data were collected from the patients,and flow cytometry was used to detect the immunophenotypes and functional markers of NK cells.Blood samples from 10 healthy individuals collected during the same period served as controls.Correlations between NK cell indicators and laboratory test results were analyzed,and differences between KPLABSI patients with and without diabetes mellitus were compared.The results showed that KPLABSI pa-tients exhibited significant hyperinflammatory responses,liver parenchymal damage,and impaired liver syn-thetic function.Meanwhile,NK cells in these patients exhibited remarkable immunophenotypic and func-tional changes:CD158e expression was significantly lower than that in the healthy control group(P＜0.000 1),and perforin(PFN)expression was significantly reduced in KPLABSI patients with diabetes mellitus compared with those without(P=0.023).Further correlation analysis revealed that NK cells are involved in the complex immune-metabolic interactions during the occurrence and development of KPLABSI.This study preliminarily suggests that NK cells play a crucial role in the anti-infective immunity among KPLABSI patients,and that hyperglycemia promotes the occurrence and progression of KPLABSI by affecting the expression level of PFN in NK cells.