The Effect of Iron Therapy in Paroxysmal Nocturnal Hemoglobinuria

Two patients with paroxysmal nocturnal hemoglobinuria who were iron deficient were treated with parenteral iron compounds. In both instances, a marked increase in hemoglobinuria followed, beginning 4 days after the first administration of the iron compound. The rise in hemolysis paralleled the rise in reticulocyte count. When erythropoiesis was suppressed with transfusion, the administration of iron did not bring about an increase in hemolysis. This indicates that the effect of iron in bringing about hemolysis in patients with paroxysmal nocturnal hemoglobinuria is due to an increase in erythropoiesis, resulting in the production of excessive numbers of complement-sensitive cells.