Pathogenesis of the glomerular abnormality in cyanotic congenital heart disease

We present evidence of 2 distinct glomerular abnormalities in cyanotic cong enital heart disease-vascular and nonvascular-each believed to reflect a di stinct pathogenesis. Glomeruli from both kidneys were studied with light mi croscopy in 13 necropsied cyanotic patients and in 8 controls. The vascular study characterized hilar arteriolar dilatation, capillary diameter, glome rular diameter, and capillary engorgement with red blood cells. The nonvasc ular study characterized juxtaglomerular cellularity, mesangeal cellularity , mesangeal matrix, focal interstitial fibrosis, and megakaryocytic nuclei per cm(2) of renal cortex. There was a significant increase in each of the above vascular and nonvascular items of interest relative to controls. Elec tron microscopy identified whole megakaryocytes with their cytoplasm in glo meruli. The vascular abnormality is believed to result from intraglomerular release of nitric oxide. The nonvascular abnormality is believed to result from platelet-derived growth factor and transforming growth factor-beta. ( C) 2000 by Excerpta Medico, Inc.