Kinetic analysis of the blood clearance and organ uptake curves of IgG-coated red cells in HLA-typed controls and patients with Wegener's granulomatosis.

Abstract

Reticuloendothelial function and HLA type were studied in 22 controls and 15 patients with Wegener's granulomatosis (WG). IgG-coated red cells were injected intravenously and half-life times of blood disappearance and liver spleen uptake curves were related to the degree of antibody coating. Erythrocytes with 13,990 molecules of IgG per cell gave biexponential blood disappearance curves and were suitable for measuring splenic reticuloendothelial function. Half-life times thus obtained were not significantly different for individuals with the HLA-DR2 or DR3 phenotype. In WG patients with major disease activity, blood clearance of the injected cells was considerably decreased. Kinetic analysis of blood disappearance and spleen uptake curves revealed that this was partly due to a decrease in reversible trapping of the cells in the spleen. This suggests that a blocking effect of circulating immune complexes on splenic Fc receptors is not likely to be the sole cause of the observed hyposplenism.