T-cell receptor repertoires as potential diagnostic markers for patients with COVID-19

Objective: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is an ongoing global health emergency. T-cell receptors (TCRs) are crucial mediators of antiviral adaptive immunity. This study sought to comprehensively characterize the TCR repertoire changes in patients with COVID-19. Methods: A large sample size multi-center randomized controlled trial was implemented to study the features of the TCR repertoire and identify COVID-19 disease-related TCR sequences. Results: It was found that some T-cell receptor beta chain (TCR beta) features differed markedly between COVID-19 patients and healthy controls, including decreased repertoire diversity, longer complementarity-determining region 3 (CDR3) length, skewed utilization of the TCR beta variable gene/joining gene (TRBV/J), and a high degree of TCR beta sharing in COVID-19 patients. Moreover, this analysis showed that TCR repertoire diversity declines with aging, which may be a cause of the higher infection and mortality rates in elderly patients. Importantly, a set of TCR beta clones that can distinguish COVID-19 patients from healthy controls with high accuracy was identified. Notably, this diagnostic model demonstrates 100% specificity and 82.68% sensitivity at 0-3 days post diagnosis. Conclusions: This study lays the foundation for immunodiagnosis and the development of medicines and vaccines for COVID-19 patients. (C) 2021 The Author(s). Published by Elsevier Ltd on behalf of International Society for Infectious Diseases.