Elevated IgG immune complexes in children with atopic eczema

The levels of serum IgG complement-fixing immune complexes were studied in 20 children with atopic eczema and in 10 children with allergic rhinitis as control subjects with the use of a Raji cell assay. Immune-complex levels were strikingly elevated in those with eczema, 50 +/- 10 SE micrograms/ml, compared to control subjects 11 +/- 9 micrograms/ml (p less than 0.0047), the latter falling within the range for nonallergic subjects. Levels tended to be higher in those subjects with more severe eczema, but there was no statistically significant correlation, nor were levels correlated with serum IgE. Sucrose-density gradient analysis demonstrated the immune complexes to be present in two peaks, 8 to 10S and 21S or higher. High-molecular-weight IgG immune complexes that are complement-fixing may promote the characteristic pruritus of eczema by formation of anaphylactic complement fragments and the release of inflammatory substances from cutaneous mast cells, as well as contributing to the impaired cell-mediated immunity associated with the disease.