Convalescent COVID-19 patients are susceptible to endothelial dysfunction due to persistent immune activation
Florence WJ Chioh, Siew‐Wai Fong, Barnaby Edward Young, Kan Xing Wu, Anthony Siau, Shuba Krishnan, Yi‐Hao Chan, Guillaume Carissimo, Louis LY Teo, Fei Gao, Ru‐San Tan, Liang Zhong, Angela S. Koh, Seow Yen Tan, Paul Anantharajah Tambyah, Laurent Rénia, Lisa F. P. Ng, David Chien Lye, Christine Cheung
Abstract
Numerous reports of vascular events after an initial recovery from COVID-19 form our impetus to investigate the impact of COVID-19 on vascular health of recovered patients. We found elevated levels of circulating endothelial cells (CECs), a biomarker of vascular injury, in COVID-19 convalescents compared to healthy controls. In particular, those with pre-existing conditions (e.g., hypertension, diabetes) had more pronounced endothelial activation hallmarks than non-COVID-19 patients with matched cardiovascular risk. Several proinflammatory and activated T lymphocyte-associated cytokines sustained from acute infection to recovery phase, which correlated positively with CEC measures, implicating cytokine-driven endothelial dysfunction. Notably, we found higher frequency of effector T cells in our COVID-19 convalescents compared to healthy controls. The activation markers detected on CECs mapped to counter receptors found primarily on cytotoxic CD8 + T cells, raising the possibility of cytotoxic effector cells targeting activated endothelial cells. Clinical trials in preventive therapy for post-COVID-19 vascular complications may be needed.