Peripheral Immune Landscape of Human Liver Allograft Rejection

Peripheral blood mononuclear cell (PBMC) samples were collected from a cohort of liver transplant recipients. The cohort included post-transplant blood samples from 44 patients, comprising 23 cases without rejection (non-rejection, NR) and 21 cases with pathologically confirmed T cell–mediated rejection (TCMR, R). All TCMR samples were obtained prior to anti-rejection therapy. Diagnoses were established according to the Banff criteria and independently reviewed by two senior pathologists. The study was approved by the institutional ethics committee, and informed consent was obtained from all participants. To characterize the circulating immune landscape during liver allograft rejection, high-dimensional single-cell profiling was performed using cytometry by time-of-flight (CyTOF). PBMC suspensions were stained with a customized 35-plex heavy metal-labeled antibody panel. Data acquisition was subsequently conducted on a Lunarion mass cytometer (Polaris Biology). After stringent quality control and data processing, a total of 4,124,622 live single cells were retained and annotated into 31 distinct immune cell types for downstream analysis.