COVID-19, the disease caused by the SARS-CoV-2 virus, can progress to multi-system organ failure and viral sepsis characterized by respiratory failure, arrhythmias, thromboembolic complications, and shock with high mortality. Autopsy and pre-clinical evidence implicate aberrant complement activation in endothelial injury and organ failure. Erythrocytes express complement receptors and are capable of binding immune complexes; therefore, we investigated complement activation in COVID-19 patients using erythrocytes as a tool to diagnose complement activation. We discovered enhanced C3b and C4d deposition on erythrocytes in COVID-19 sepsis patients and non-COVID sepsis patients compared with healthy controls, supporting the role of complement in sepsis-associated organ injury. Our data suggest that erythrocytes may contribute to a precision medicine approach to sepsis and have diagnostic value in monitoring complement dysregulation in COVID-19-sepsis and non-COVID sepsis and identifying patients who may benefit from complement targeted therapies.

中文翻译：

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红细胞识别 COVID-19 患者的补体激活

COVID-19 是由 SARS-CoV-2 病毒引起的疾病，可发展为多系统器官衰竭和病毒性败血症，其特征是呼吸衰竭、心律失常、血栓栓塞并发症和休克，死亡率很高。尸检和临床前证据表明，异常补体激活会导致内皮损伤和器官衰竭。红细胞表达补体受体并能够结合免疫复合物；因此，我们使用红细胞作为诊断补体激活的工具，研究了 COVID-19 患者的补体激活。我们发现与健康对照组相比，COVID-19 脓毒症患者和非 COVID 脓毒症患者的红细胞 C3b 和 C4d 沉积增强，支持补体在脓毒症相关器官损伤中的作用。