Next generation sequencing reveals novel alterations in B-cell heavy chain receptor repertoires associated with acute-on-chronic liver failure

Acute-on-chronic liver failure (ACLF) is a newly-defined serious syndrome with major features of acute decompensation (AD) of hepatic cirrhosis, liver failure and failure of multiple other organs. To date, the mechanism underlying the development and progression of ACLF remains to be fully elucidated. It has been noted that ACLF is associated with immune dysregulation. However, studies have mainly focused on T-cell responses. The present study aimed to determine the composition and alterations of B-cell receptor (BCR) heavy chain repertoires associated with ACLF using next generation sequencing (NGS). A total of six patients with hepatitis B virus (HBV)-related ACLF and six healthy control subjects were prospectively enrolled in the present study. The B-cell immunoglobulin heavy chain (IGH) repertoires in peripheral blood mononuclear cells (PBMCs) obtained from the patients with HBV-related ACLF and the control subjects were analyzed using NGS, coupled with multiplex polymerase chain reaction, were Illumina sequenced, and were further characterized using the international ImMunoGeneTics database. The distribution of the BCR complementarity-determining region 3 (CDR3) variable (V), diversity (D) and joining (J) and V-J gene segments were found to be comparable between the ACLF and control groups. Of note, the degree of clonal expansion in the ACLF group was significantly higher than that in the control group (P<0.05). Furthermore, a t-test of the distribution ratio of the V, D, J and V-J combinations in patients with ACLF and control subjects revealed differentially expressed genes. In total, six genes were upregulated and 19 genes were downregulated in response to ACLF. The difference between these two groups was statistically significant (P<0.05). The approach used in the present study was feasible and effective for analyzing peripheral B-cell repertoires in HBV-related ACLF. These results provide direct evidence that the BCR repertoire is important in immune responses, autoimmunity and alloreactivity, and that there is a link between the BCR repertoire and HBV-ACLF. Therefore, ACLF-specific BCR CDR3 sequences hold promise for therapeutic benefit to HBV-ACLF in the future.