Urinary excretion of glomerular basement membrane antigens in premature infants and the newborn.

25 premature infants, 8 mature newborns and 25 children between 5 and 15 years of age were examined for urinary excretion of glomerular basement membrane (GBM) antigens. For the characterization of the excreted GBM antigen, immunoelectrophoresis was applied. In the group of 25 premature infants 23 showed alpha-1-mobility, in the group of 8 mature newborns all showed alpha-1-mobility, and in the group of the 25 children aged 5--15 years 24 showed migration into the alpha-2-zone. Differentiating, whether the difference between the immature and mature GBM is quantitative or qualitative, the immunoelectrophoretical difference points to the interpretation that the premature GMB shows a unique chemical composition.