Late recovery of renal function in a woman with the hemolytic uremic syndrome

A case of hemolytic uremic syndrome (HUS) is reported in a woman taking oral contraceptives. A first renal biopsy showed the typical lesions of thrombotic microangiopathy. Some arterioles showed fibrinoid necrosis of the walls. Concentric intimal proliferation with narrowing and sometimes occlusion of the lumina of vessels was observed. Many glomeruli showed a moderate increase of the mesangium, mild mesangial proliferation and thickening of capillary walls due to splitting of basement membranes. Other glomeruli appeared contracted with severe narrowing of the capillary lumina. Diffuse and severe tubular necrosis was present. Immunofluorescence showed intense fibrin deposition in vessels and glomerular capillaries. No immunoglobulin or complement deposits were found. She was treated with heparin, dipyridamole and hemodialysis; and after more than three months, her urinary output rose above 500 ml; and six monsths after the onset of anuria, dialysis treatment was stopped. This case emphasizes the possibility that HUS in adults is not invariably irreversible and that, despite prolonged oliguria, recovery of renal function can be obtained. Therefore, in adult patients affected by HUS, dialysis should not be discontinued prematurely; moreover, bilateral nephrectomy, for treatment of severe hypertension and microangiopathic hemolytic anemia, should be performed with caution.