Membranous nephropathy:: a family report leading to new pathophysiologic concepts

Membranous glomerulonephritis (MGN) is a major cause of the nephrotic syndrome and chronic renal insufficiency. Studies on the reactivity of nephritogenic antibodies implicated in a case of antenatal MGN led to identify for the first time a target of the immune conflict in glomeruli, neutral endopeptidase (CD10). This enzyme that is restricted to certain tissues, being strongly expressed in the placenta and on glomerular podocytes, is involved in the catabolism of a number of regulatory peptides, particularly those involved in vasomotricity. We showed that the nephritogenic antibodies blocked enzymatic activity and that the mother became immunized at the time of a previous pregnancy because she was neutral endopeptidase-deficient. Two additional families have been identified since then. The pathophysiologic mechanisms that we have unraveled are reminiscent of Rhesus immunization and open up new avenues for therapeutic intervention.