RESUMEN
BACKGROUND/AIM: Some reports showed encouraging efficacy of immune checkpoint inhibitors among patients who experienced immune-related adverse events (irAEs). Thus, characterization of T-cell repertoire and immune signatures in peripheral blood mononuclear cells (PBMCs) and tumors before and after immune checkpoint inhibitors treatment should contribute to better understanding of irAE-provoked anticancer immune responses. MATERIALS AND METHODS: We applied expression analysis of immune-related genes and T-cell receptor sequencing in tumor and PBMCs from five patients with renal cell carcinoma before combined immunotherapy and at the onset of severe irAEs. RESULTS: We found that the cluster of differentiation 8 (CD8)/forkhead box P3(FOXP3), granzyme B(GZMB)/CD3, perforin 1(PRF1)/CD3 and programmed cell death 1(PD1)/CD8 expression ratios were significantly elevated in PBMCs at the onset of irAEs. In addition, we found expansion of certain T-cell clones in metastatic tissue after irAEs, which were already increased in peripheral blood at the onset of irAEs. CONCLUSION: irAE-provoked T-cells may also circulate and attack distant tumors, leading to durable response in patients with irAEs.
