Detection of circulating soluble immune complexes in patients with various renal diseases.

Sera from patients with various types of glomerulonephritis (GN) as well as sera from rabbits with acute serum sickness were studied for the presence of circulating immune complexes (IC). The method used is based on the observation that IC inhibit the uptake of IgG aggregates by guinea-pig peritoneal macrophages. Inhibition significantly greater than with normal human sera was found with sera of patients with membranous GN, membranoproliferative GN, focal glomerular sclerosis, minimal change nephrotic syndrome, acute septicaemic glomerular diseases and systemic lupus erythematous. IC were also detected in rabbits with acute serum sickness during the period of immune elimination.