Respiratory failure and acute kidney injury (AKI) are associated with high mortality in SARS-CoV-2-associated Coronavirus disease 2019 (COVID-19). These manifestations are linked to a hypercoaguable, pro-inflammatory state with persistent, systemic complement activation. Three critical COVID-19 patients recalcitrant to multiple interventions had skin biopsies documenting deposition of the terminal complement component C5b-9, the lectin complement pathway enzyme MASP2, and C4d in microvascular endothelium. Administration of anti-C5 monoclonal antibody eculizumab led to a marked decline in D-dimers and neutrophil counts in all three cases, and normalization of liver functions and creatinine in two. One patient with severe heart failure and AKI had a complete remission. The other two individuals had partial remissions, one with resolution of his AKI but ultimately succumbing to respiratory failure, and another with a significant decline in FiO₂ requirements, but persistent renal failure. In conclusion, anti-complement therapy may be beneficial in at least some patients with critical COVID-19.

呼吸衰竭和急性肾损伤 (AKI) 与 2019 年 SARS-CoV-2 相关冠状病毒病 (COVID-19) 的高死亡率相关。这些表现与高凝、促炎状态和持续的全身补体激活有关。三名不愿接受多种干预的重症 COVID-19 患者进行了皮肤活检，记录了微血管内皮中末端补体成分 C5b-9、凝集素补体途径酶 MASP2 和 C4d 的沉积。给予抗 C5 单克隆抗体依库珠单抗导致所有 3 例患者的 D-二聚体和中性粒细胞计数显着下降，2 例患者的肝功能和肌酐恢复正常。一名患有严重心力衰竭和 AKI 的患者完全缓解。另外两人获得部分缓解，其中一人的 AKI 得到缓解，但最终死于呼吸衰竭，另一人的 FiO ₂需求显着下降，但出现持续性肾衰竭。总之，抗补体治疗至少对某些危重 COVID-19 患者可能有益。