EXPERIMENTAL GLOMERULONEPHRITIS

TLDR

Injecting foreign serum proteins into rabbits induces glomerulonephritis that mimics acute, subacute, and chronic human disease. The severity and type of glomerulonephritis depend on the antibody response: high titers cause acute, self‑limited disease, while low titers lead to subacute or chronic lesions driven by circulating antigen‑antibody complexes that deposit in the renal basement membrane and persist even after antigen withdrawal, providing an antigen‑driven model distinct from nephrotoxic serum nephritis.

Abstract

Daily injections of any one of several foreign serum proteins produced in rabbits functional and morphological alterations similar to those seen in acute, subacute, and chronic human glomerulonephritis. The critical factor determining whether a rabbit would develop renal disease and the type of disease developed was the amount of antibody the rabbit formed. Those responding with much antibody were likely to develop an acute, self-limited glomerulonephritis and to be subsequently immune to further renal damage. Those responding with antibody barely sufficient to neutralize the antigen injected developed subacute and chronic glomerulonephritis. In the circulation of the rabbits with chronic glomerulonephritis, there was a daily recurring antigen-antibody reaction in the region of near antigen excess to near antibody excess which presumably led to the disease. Antigen apparently in the form of antigen-antibody complexes was deposited along the renal capillary basement membranes coincident with the development of subacute and chronic glomerulonephritis. Once developed, the morphologic stigmata of chronic glomerulonephritis persisted even after injections of antigen were stopped. However, in milder instances the renal function recovered in part after stopping antigen. This experimental model has several implications: first, the renal injury is precipitated by antigens with no known affinity for, or immunologic relationship to, kidney; second, antigen antibody complexes localize in the kidney, apparently on the basis of non-immunologic factors, and may be an etiologic agent of renal injury; third, severe hypersensitivity disorders can be related specifically to relatively poor as well as to good antibody responses; and finally, the pathogenesis suggested here offers an alternative to that of nephrotoxic serum nephritis for the experimental approach to the study of human glomerulonephritis.