The clearance of heterologous antibodies in experimental antibasement membrane antibody mediated glomerulonephritis

Abstract

A study of the clearance of anti GBM antibodies is important for an understanding of the pathogenesis of Goodpasture's syndrome. This paper reports a study of the sequential clearance of heterologous anti-glomerular basement membrane antibodies in the neonatal rat. A single intraperitoneal injection was followed by rapid and linear binding of injected antibodies to glomerular basement membranes, particularly to those glomeruli in the corticomedullary region. GBM bound antibodies were cleared gradually through the mesangium and significant amounts of antibodies still remained bound after 6 months. Subsequent injections of antibodies failed to provoke morphological abnormalities. These experiments have shown that the glomerular basement membrane of neonatal and adult rats possesses similar antigenic sites. The mesangium plays a major role in the clearance of injected heterologous antibodies. The slow clearance of antibodies from the GBM indicates a strong affinity of antibodies to antigenic sites and that the removal of antibodies is intimately related to the slow metabolic turnover of the glomerular basement membrane. The findings help to explain some of the observations in human antibasement membrane antibody mediated disease of the Goodpasture's type.