Change Study Of Tumor Infiltrating Lymphocyte Subpopulations In Perioperative Period Of Associating Liver Partition And Portal Vein Ligation For Staged Hepatectomy(ALPPS) In The Treatment Of Massive Hepatocellular Carcinoma Of Right Lobe

ObjectiveTo evaluate the safety and effectiveness of clinical application of associating liver partition and portal vein ligation for staged hepatectomy（ALPPS）by exploring the component change of tumor infiltrating lymphocyte（TIL）subpopulations in perioperative period of ALPPS in the treatment of massive hepatocellular carcinoma（HCC）of right lobe,and analyzing the role of TIL subpopulations in HCC microenvironment.MethodsClinical data and pathological tissue specimens were collected in 15patients with massive HCC of right lobe who underwent ALPPS treatment and46 patients who underwent right hemihepatectomy during the same period from August 2018 to August 2019 in the department of hepatobiliary surgery in the First Affiliated Hospital of Guangxi Medical University.Propensity score matching（PSM）was used to match patients in the ALPPS group and the right hemihepatectomy group.Quantitative analysis of TIL in cancer and adjacent tissues between the two groups was performed by multi-color labeling immunofluorescence staining and multi-spectral imaging techniques.The TIL subpopulations include CD3⁺T cells,CD8⁺T cells,and CD4⁺T cells,Foxp3⁺Treg cells,CD20⁺B cells and CD56⁺NK cells,and the relationship between these TILs and tumor necrosis was analyze after ALPPS-Ⅰoperation.At the same time,the change trend of peripheral blood immune components was compared between two groups before and after operation 1,3,5,and 7 days.The immune components include CD3⁺T cells,CD8⁺T cells,CD4⁺T cells,CD19⁺B Cells,Treg cells,NK cells,interleukin-6,complement（C1q,C3,C4）and immunoglobulins（Ig A,Ig G,Ig M）.ResultsThe TIL expression rate was compared between the matched right hepatectomy group and the ALPPS group（including stageⅠand stageⅡ）.Except for the expression rate of Treg cells of the right hepatectomy group in the cancer tissue was higher than that in the adjacent tissue（P=0.043）,there was no statistically significant difference in the remaining TIL between the ALPPS group stage I and II,the right hepatectomy group and the ALPPS group,or between the same group in cancer and adjacent tissues.The proportion of tumor necrosis volume on the 7^th day after ALPPS-Ⅰsurgery was significantly higher than that before surgery（P=0.024）through continuous measurement of tumor volume and tumor necrosis volume.However,there was no significant difference in the proportion of tumor necrosis volume between the ALPPS-Ⅰpreoperation and 3^rd day after operation,3^rd and 7^th day after operation.In the perioperative period of ALPPS-Ⅰ,the proportion of tumor necrosis volume in the high CD8⁺T cell infiltration group was significantly higher than that in the low CD8⁺T cell infiltration group（P=0.048）.In the monitoring of peripheral blood immune components before and after surgery,the content of component C1q and C3 in ALPPS-Ⅰstage was significantly higher than stageⅡ（C1q:P=0.007,C3:P=0.047）.However,peripheral blood lymphocyte subpopulations,immune effector molecules,IL-6and other immune components between the right hemihepatectomy group,ALPPS-ⅠandⅡstage had all no statistical difference before and after operation1,3,5,and 7 days.ConclusionsDuring the perioperative period of ALPPS,the TIL infiltration level maintained a dynamic balance.Compared with right hemihepatectomy,the ALPPS procedure itself did not cause a decrease in TIL infiltration and pathological changes in immune components of peripheral blood,which cannot result in a severe immunosuppression.From the perspective of immunology,ALPPS is safe and feasible for the treatment of massive HCC.In addition,high CD8⁺T cell infiltration was associated with increasing tumor necrosis in the perioperative period of ALPPS.