Fig. 4

C3 convertase formation assay and decay assay. a Commercial human CFH exhibits a strong formation-impeding activity of the C3 convertase (C3bBb) assembled on immobilized C3b in a dose-dependent manner. b Commercial human CFH accelerates the decay of the C3 convertase (C3bBb) assembled on immobilized C3b in a dose-dependent manner. c, d Pre-incubated CFH (4 μg/ml) with purified anti-CFH autoantibodies from our patient and the aHUS patient, and total IgG from three healthy control individually at concentrations of 10 μg/ml, 50 μg/ml, and 100 μg/ml, respectively. Anti-CFH autoantibodies purified from our patient showed significantly reduced formation-impeding activities in a dose-dependent manner (c) and no significant effects on the decay-accelerating activities of CFH (d). Notes: P: Our patient; aHUS: the aHUS patient with anti-CFH autoantibodies; HC: healthy controls. Each assay was performed three times, and the data are shown as the mean ± SD