IT IS fitting that the shape of a sickled red blood cell (RBC) should resemble that of a kidney. The patient with sickle cell trait or disease is liable to experience several types of sickle cell nephropathy. The best known of these is gross hematuria, seen most often with the trait. The bleeding arises just beneath the pelvic mucosa, where masses of sharp-pointed sickled RBCs engorge and rupture venules. The low oxygen pressure and interstitial hypertonicity, which are characteristic of the renal medulla, undoubtedly favor the formation of these sickle cell masses.
The same concept applies to the second of the nephropathies, papillary necrosis. This is a slowly developing process affecting one papilla at a time and is not associated with acute renal failure. The third nephropathy is the nephrotic syndrome, associated with glomerular microinfarcts resulting from plugs of sickled RBCs. It is uncommon and unresponsive to steroid therapy. The