Terminal complement inhibition dampens the inflammation during COVID-19.

Emerging evidence suggests that activation of the complement system is critical in the pathogenesis of the novel coronavirus, SARS-CoV-2, the causative agent of COVID-19 related lung injury. Inhibition of the terminal complement pathway by targeting complement protein 5 (C5) may be an effective therapeutic intervention in CoV-mediated disease.1 Paroxysmal nocturnal haemoglobinuria (PNH) is a rare, acquired hematopoietic stem cell (HSC) disease characterized by intravascular haemolysis, increased thromboembolic risk and bone marrow failure.2.