Characteristics of circulating immune cells in HBV-related acute- on-chronic liver failure following artificial liver treatment

Background: and aim: Liver failure, which is predominantly caused by hepatitis B (HBV) can be improved by an artificial liver support system (ALSS). This study investigated the phenotypic heterogeneity of immunocytes in patients with HBV-related acute-on-chronic liver failure (HBV-ACLF) before and after ALSS therapy. Methods A total of 22 patients with HBV-ACLF who received ALSS therapy were included in the study. Demographic and laboratory data were collected and analyzed during hospitalization. Immunological features of peripheral blood in the patients before and after ALSS were detected by mass cytometry analyses. Results Patients with Grade I according to the ACLF Research Consortium score were considered to have recovered. In total, 12 patients recovered and 10 patients did not. According to the immunological features data after ALSS, the proportion of circulating monocytes was significantly higher in unrecovered patients, but there were fewer γδT cells compared with those in recovered patients. Characterization of 37 cell clusters revealed that the frequency of effector CD8 + T ( P  = 0.003), CD4 + T CM ( P  = 0.033), CD4 + T EM ( P  = 0.039), and inhibitory natural killer (NK) cells ( P  = 0.029) decreased in HBV-ACLF patients after ALSS therapy. Sub group analyses after treatment showed that the recovered patients had higher proportions of CD4 + T CM ( P  = 0.010), CD4 + T EM ( P  = 0.021), and γδT cells ( P  = 0.003) and a lower proportion of monocytes ( P  = 0.012) compared with the unrecovered patients. Conclusions Changes in effector CD8 + T cells, effector and memory CD4 + T cells, and inhibitory NK cells are associated with ALSS treatment of HBV-ACLF. Moreover, monocytes and γδT cells exhibited the main differences when patients obtained different prognoses. The phenotypic heterogeneity of lymphocytes and monocytes may contribute to the prognosis of ALSS and future immunotherapy strategies.