免疫检查点抑制剂已经改变了癌症治疗的方式。然而，它们与独特的副作用谱相关，被称为免疫相关不良事件（irAEs），如果不及时治疗，可导致明显的发病率，并迅速进展为严重或危及生命的事件。在免疫疗法开始之前，鉴定irAEs的预测性生物标记是一个关键的研究领域。T细胞受体β（TCRB）变量（TRBV）基因内的多态性已被认为与自身免疫性疾病相关，并可能在机制上与irAEs相关联。然而，TCRB基因座的重复性和不完整的基因组组装过去妨碍了对TRBV多态性的评估。我们采用了一种新方法，通过对外周血总RNA中重排的TCRB链进行长片段下一代测序，评估了TRBV多态性与接受免疫疗法治疗癌症患者的irAEs之间的联系。我们采用复合物多聚酶链式反应（multiplex PCR）创建跨越三个β链互补决定区域（CDR）区域的扩增子，用于检测在遗传编码的框架和CDR1、CDR2区域以及CDR3分析中的多态性。通过Ion Torrent测序获得的扩增子序列，构建了每个个体的TRBV等位基因概况，并与irAE注释进行关联，以确定与严重irAEs（≥3级）相关的单倍型。我们的研究包括81名在癌症免疫疗法治疗过程中出现irAEs的患者。通过对这81个TRBV等位基因概况进行主成分分析，然后进行k均值聚类，我们确定了六个主要的TRBV单倍型。令人惊讶的是，我们发现这个患者组有三分之一的人拥有一种TRBV等位基因单倍型，似乎对严重irAEs具有保护作用。数据表明，长片段的TCRB库测序有可能识别与严重irAEs风险相关的TRBV单倍型群体。遗传编码的TRBV多态性可能作为严重irAEs的预测性生物标记。© 作者（或其雇主）2023年授权重复使用CC BY-NC。不允许商业再利用。由BMJ出版。

Immune checkpoint inhibitors have revolutionized cancer treatment. However, they are associated with a unique spectrum of side effects, called immune-related adverse events (irAEs), which can cause significant morbidity and quickly progress to severe or life-threatening events if not treated promptly. Identifying predictive biomarkers for irAEs before immunotherapy initiation is therefore a critical area of research. Polymorphisms within the T-cell receptor beta (TCRB) variable (TRBV) gene have been implicated in autoimmune disease and may be mechanistically linked to irAEs. However, the repetitive nature of the TCRB locus and incomplete genome assembly has hampered the evaluation of TRBV polymorphisms in the past.We used a novel method for long-amplicon next generation sequencing of rearranged TCRB chains from peripheral blood total RNA to evaluate the link between TRBV polymorphisms and irAEs in patients treated with immunotherapy for cancer. We employed multiplex PCR to create amplicons spanning the three beta chain complementarity-determining regions (CDR) regions to enable detection of polymorphism within the germline-encoded framework and CDR1 and CDR2 regions in addition to CDR3 profiling. Resultant amplicons were sequenced via the Ion Torrent and TRBV allele profiles constructed for each individual was correlated with irAE annotations to identify haplotypes associated with severe irAEs (≥ grade 3).Our study included 81 patients who had irAEs when treated with immunotherapy for cancer. By using principal component analysis of the 81 TRBV allele profiles followed by k-means clustering, we identified six major TRBV haplotypes. Strikingly, we found that one-third of this cohort possessed a TRBV allele haplotype that appeared to be protective against severe irAEs.The data suggest that long-amplicon TCRB repertoire sequencing can potentially identify TRBV haplotype groups that correlate with the risk of severe irAEs. Germline-encoded TRBV polymorphisms may serve as a predictive biomarker of severe irAEs.© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.