Absence of Circulating IgG Immone Complexes in C57B1/6 Mice with Age-Associated Renal Igg Deposits

Abstract

The L1210 enzyme-linked immunoassay (ELIA) for circulating immune complexes, previously developed for use in humans, has been adapted for use in mice. The assay detected elevated levels of immune complexes in 100% of NZB/W female mice (6-10 months old) with age-related immune complex-mediated glomerulonephritis. Application of the assay to the serum of one year old C5TB1/6 male mice failed to demonstrate elevated levels of serum immune complexes in spite of the routine finding of renal deposition of IgG plus proteinuria in aged mice of this strain. Since the LI210 ELIA detects all IgG-containing immune complexes, regardless of size or complement fixing capacity, these results suggest that the renal IgG deposits seen in aged C57B1/6 mice are not derived from circulating IgG immune complexes.