Characteristics of profiling the peripheral blood T‐cell receptor repertoire in patients with diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin’s lymphoma with strong heterogeneity and high invasiveness. The high-throughput sequencing of peripheral blood T cell receptor (TCR) can analyze the individual's immune response and directly reflect the immune status. This study aimed to detect the TCR β chain in peripheral blood of DLBCL patients and the control group, and also to analyze the characteristics of the TCR CDR3 immune repertoire of DLBCL patients before and after chemotherapy. We found that the diversity of the baseline TCR repertoire in DLBCL samples were significantly reduced than those in the control group, while there was no difference in diversity before and after chemotherapy. Patients with 53.5 years or older, stage III-IV, high IPI score and ECOG performance showed a limited TCR CDR3 repertoire. The baseline TCR diversity of patients who achieved complete remission (CR) was higher than that of the non-remission (Non-CR) group. Comparing the V gene and J gene of the CR group and the Non-CR group, it was found that the two Vβ genes have the potential to predict the therapeutic effect. In addition, standard first-line chemotherapy regimen caused changes in the frequency of T cell clones in DLBCL patients. The similarity index of CR group was lower, indicating that more changes in TCR clones occurred after chemotherapy. This study revealed the unique TCR CDR3 immune repertoire of DLBCL patients and its relationship with clinical characteristics. Dynamic monitoring of TCR diversity can more accurately predict clinical benefit.