C5 and acute kidney injury: Reasons for not applying C5 inhibitor treatment (provided for 28 of 56 patients) included mild clinical presentation characterised by the absence of acute kidney injury requiring dialysis (n = 13), no relapse after plasma exchange (n = 5), delayed diagnosis (n = 4), delays in national drug approval (n = 3), advanced chronic kidney disease (CKD) at presentation (n = 2), and financial constraints (n = 1) (not shown).