Renal Hemosiderosis in the Hemolytic Anemias: Diagnosis by Means of Needle Biopsy

Renal hemosiderosis has been ascertained by needle biopsy in eight patients. Two of them were affected by paroxysmal nocturnal hemoglobinuria, three by autoimmune hemolytic anemia, one by paroxysmal cold hemoglobinuria, one by thalassemia minor, and one by hereditary spherocitosis. Although the extent of the hemosiderin infiltration of the kidney varied, the distribution of this pigment was limited almost exclusively to the proximal convoluted tubule in all cases. Only one patient with autoimmune hemolytic anemia, who had previously received numerous blood transfusions, had hemosiderin infiltration of the liver and spleen. In all other cases hemosiderosis limited to the cells of the proximal convoluted tubule appears to be a histologic sign of hemoglobin reabsorption. This was more evident when intravascular hemolytic episodes were recorded or when a moderate degree of hemoglobinemia suggested the occurrence of a slight, persistent intravascular hemolysis. No significant impairment of tubular function was found, even in patients with most marked hemosiderosis.