Pre-opsonisation with human SAP rescued and increased C3 deposition in both IgG- (% of increase, 1 min, 87.9 ± 25.2%, P = 0.022; 20 min, 139.6 ± 14.6%, P < 0.0001) and SAP-depleted (1 min, 14.3 ± 4.4%; 20 min, 144.5 ± 23.8%, P = 0.001) plasma as well as in the control (1 min, 75.0 ± 43.4%; 20 min, 36.1 ± 13.3%, P = 0.008) (Fig. 3g), thus suggesting an effect of SAP in promoting complement activation on A. fumigatus under mimed immunosuppressive conditions of antibody deficiencies. This evidence concerns the gene C3 and agammaglobulinemia.