Membranoproliferative glomerulonephritis in childhood cirrhosis associated with alpha1-antitrypsin deficiency.

Three alpha1-antitrypsin (alpha1AT) deficient, protease inhibitor type ZZ children who died from cirrhosis and its complications had membranoproliferative glomerulonephritis at postmortem examination. During life, all three had clinical and laboratory evidence of renal disease which became apparent when hepatic decompensation developed. Immunofluorescence studies and electron microscopy performed in one patient revealed subendothelial deposits of alpha1AT, complement, and immune globulins along the glomerular basement membrane. The pathogenesis of these renal lesions is speculative. Glomerular lesions were not observed in kidney sections of 16 children who died from cirrhosis but who were not alpha1AT-deficient. The present study suggests that renal involvement may be yet another manifestation of disease associated with alpha1AT deficiency.