Surgery/anesthesia may cause monocytes to promote tumor development.

Background: The immune system of patients undergoing major surgery usually has obvious immune responses during the perioperative period, and the patient's immune status would affect the patient's prognosis. In this study single-cell sequencing technology was used to investigate the effect of surgery/anesthesia on peripheral blood mononuclear cells (PBMCs) in depth during the perioperative period.

Methods: We performed an in-depth analysis of our previously published data, which included a total of 4 patients were recruited in this study. Their peripheral blood samples were collected pre operation, 0, 24, and 48 h post operation, and then PBMCs were extracted, followed by single cell sequencing. The results of sequencing were analyzed with R packages seurat and scSTAR. Finally, RT-PCR technology was used to verify the expression of key genes in monocyte.

Results: The ratio of CD4⁺ and CD8⁺ T cells and Tregs showed little change, and the function of CD4⁺ and CD8⁺ T cells recovered soon. The function of Treg had not been restored 48 h post operation. Non-classical monocyte was impressed after surgery and showed no recovery trend within 48 h. Similar to scRNA-seq, the expression levels of MDM2 and SESN1 in patients with tumor increased significantly after surgery.

Conclusions: Surgery/anesthesia had little effect on CD4⁺ and CD8⁺ T cells, and continued to affect the functional changes of Treg. It had more impact on monocytes, which may cause them to promote tumor development to a certain extent.