To the Editor.
—We read with interest the article by Engel et al that appeared in a recent issue of the Archives (1982;142:287-288) and the editorial by Dr Crosby (233-235). These and other observations make it clear that bone marrow iron may not always reflect body iron stores in some patients' conditions. Many of these patients' conditions are characterized by sequestered deposits of iron that are unavailable for hematopoiesis, as in paroxysmal nocturnal hemoglobinuria (PNH)1 and idiopathic pulmonary hemosiderosis.2 Whether the serum ferritin levels would be reflective of the sequestered stores of iron has not been investigated. Our recent experience with a patient with PNH and iron deficiency anemia prompted this letter.
Report of a Case.
—A 25-year-old man was admitted to Cook County Hospital, Chicago, on Feb 23, 1981, for evaluation of anemia. A diagnosis of aplastic anemia had been made ten years earlier at another hospital,