Crystal-associated nephropathy in patients with brushite nephrolithiasis

Brushite stone formers combine the interstitial plaque of calcium oxalate stone formers with the collecting duct apatite plugs found in stone formers with intestinal bypass. Collecting duct injury and interstitial fibrosis are severe. Prominent cortical fibrosis, tubule atrophy, and glomerular pathology seem secondary to the collecting duct plugging. We believe crystallization obstructs and destroys terminal collecting duct segments thereby damaging nephrons, perhaps via intranephronal obstruction, and producing a hitherto unrecognized renal disease.