[Characteristics of IgH-CDR3 repertoire of peripheral B cells in a patient with primary biliary cholangitis: a preliminary study using high-throughput sequencing].

Objective To analyze the characteristics of immunoglobulin heavy chain complementarity-determining region (IgH-CDR3) repertoire of peripheral B cells in a patient with primary biliary cholangitis (PBC) and to investigate the diversity of the immune system. Methods Arm-PCR was used to amplify the IgH-CDR3 region of circulating B cells isolated from a PBC patient, and high-throughput sequencing was used to analyze the amplified product. The characteristics of immune repertoire were analyzed by bioinformatics. Results In total, 329219 sequence reads were generated from the sample, with 325540 total CDR3 sequences and 72774 distinct CDR3 sequences, and the D50 of IGH-CDR3 was 7.7. The dominant CDR3 length of the sample was 45 nt (9.6%); the N addition with the highest frequency ranged from 13 to 14 nt (5.25%); the J trimming with the highest frequency was 0 nt (12.7%); the three most frequent V alleles were V4-59 (9.5%), V3-23 (8.1%), and V1-69 (6.4%). Conclusion The diversity of IgH-CDR3 repertoire is relatively low in this patient with PBC, with several B-cell clonal expansions. The specificity needs to be further verified after increasing the sample size. Key words: Liver cirrhosis, biliary; B cell receptor; IGH-CDR3 repertoire