Development and heterogeneity of antigens in the immature nephron. Reactivity with human antiglomerular basement membrane autoantibodies.

Indirect immunofluorescence microscopy was performed with 15 human anti-glomerular basement membrane (GBM) antibodies and mouse monoclonal antibodies to Type IV collagen (MBM4) and renal basement membranes (MBM15) on renal tissue from 6 fetuses (gestational age, 15-23 weeks), 8 infants (age, 1-21 days), and 8 children and adults (ages, 3-27 years). Of the 15 human anti-GBM antibodies that react with GBM in adult glomeruli, only 4 identified antigens in the GBM of fetal and infant glomeruli. In contrast, the monoclonal antibodies bound to basement membranes in the uninduced nephron and the GBM throughout all development stages of the fetal kidney. These studies demonstrate that the reactivity of human autoantibodies with GBM is developmentally and gestationally related--some identifying an antigen(s) in fetal glomeruli with early capillary loop formation and others reacting only with GBM in fully mature kidneys.