Defective In Vivo Fc- and C3b-Receptor Function in IgA Nephropathy

Abstract

Reticuloendothelial function was assessed in 17 patients with IgA nephropathy, using 99Tc-labeled autologous erythrocytes coated with either C3B or IgG. Results were compared with clearances in 14 normal control subjects and with a group of 14 patients with idiopathic mesangial proliferative glomerulonephritis without IgA deposition. The half-life of IgG-coated red cells in the IgA group was 69.8 ± 32.5 minutes (control 42.2 ± 9.0 minutes, P = 0.001). The half-life in the non-IgA mesangial proliferative group, 77.9 ± 31.3 minutes, was not significantly different from that of the IgA patients. Clearance of C3b-coated cells, expressed as the percentage of cells cleared at 30 minutes, was 7.1% ..