The relationship between circulating soluble ntigen-antibody complexes and the production of chronic glomerulonephritis in the rabbit.

Twenty-three rabbits were injected over long periods of time with isotopically labelled bovine serum albumin. Varying injection schedules and primary and secondary responses were studied, but all schedules were designed to preclude the presence of free circulating antibody at any time. All animals became tolerant of injected antigen after a period of 60–80 days. During the intervening period (from 10 to 60 days) large amounts of antigen—antibody complex were shown to be circulating. Proteinuria was intermittent in all animals. Histological examination of the kidneys from 50 days on showed only very minor evidence of renal damage; no animal developed chronic renal disease.