Urologic Manifestations of Paroxysmal Nocturnal Hemoglobinuria

Abstract

A long-term study of 17 patients with paroxysmal nocturnal hemoglobinuria revealed an unexpectedly high incidence of functional and anatomic renal abnormalities. All patients demonstrated varying degrees of hematuria and proteinuria distinct from hemoglobinuria. All patients also had granular casts in multiple urinalyses. Evaluation of renal function revealed hyposthenuria, abnormal tubular function and declining creatinine clearance. Radiologically, one or more of these demonstrated enlarged kidneys, renal cortical infarcts and thinning, papillary necrosis, acute renal atrophy, retroperitoneal hematoma and ureteral infarction, which were confirmed by autopsy studies. Hypertension developed in 7 patients. Urinary tract infection was uncommon and no patient had a clinical history compatible with chronic or acute pyelonephritis. Contrary to usual opinion our studies clearly showed evidence of frequent and widespread renal pathology in paroxysmal nocturnal hemoglobinuria most likely due to repeated microvascular thromboses similar to the venous thrombosis involving other organs in this disorder. Since most of these patients present initially to urologists knowledge of this entity is mandatory.