Factor H inhibits complement activation induced by liposomal and micellar drugs and the therapeutic antibody rituximab in vitro

Various classes of nanomedicine, including liposomal and micellar drugs and therapeutic antibodies, can trigger complement activation in blood and cause complement activation-related pseudoallergy (CARPA), one of the main underlying phenomena resulting in hypersensitivity reactions to infused or i.v. injected medications. In our study, we demonstrate that the alternative complement pathway regulator factor H and its engineered artificial derivative mini-factor H inhibit complement activation induced by liposomes, cremophore EL micelles and the therapeutic antibody rituximab. The results point to a major role of the alternative complement pathway and suggest that alternative pathway inhibitors could potentially be used to prevent these reactions.253