The evaluation of iron status in dialysis patients provides information essential to the planning of adequate rHuEPO treatment. Iron status of the patients can be determined from the recently available measurement of reticulocyte hemoglobin equivalent(RET-He). RET-He is measured by automated fluorescent flow cytometry using a polymethine dye, which in the reticulocyte channel, also measures the mean value of the forward light scatter histogram of mature red blood cells and reticulocytes. These values equate with reticulocyte hemoglobin concentration. In this study, to clarify the accuracy of RET-He in diagnosing iron deficiency in dialysis patients, we initially compared RET-He with such iron parameters as serum ferritin levels, transferrin saturation, and concentration of reticulocyte hemoglobin(CHr)which have been established as indicators of functional iron

Key words：Graft versus host disease, hemolytic anemia, hemoglobinuria, plasma exchange, hemodialysis 〈Abstract〉 A 53-year old man was diagnosed with myelodysplastic syndrome-refractory anemia with excess blasts(MDS-RAEB)in March 1990. In October 1998, as he developed pancytopenia with increasing myeloblasts, he was enrolled as a recipient for hematopoietic stem cell transplantation in the Japanese bone marrow bank. In February 2008, as an HLA-matched yet ABO-blood type mismatched unrelated donor was found, he was admitted to our hospital to receive bone marrow transplantation(BMT). Red blood cells and plasma were fully eliminated from the donor stem cells harvested, following administration of both busulfan and cyclophosphamide as preparative regimens. Cyclosporin A and methotrexate for the prevention of acute graft versus host disease(GVHD)were started from day 1 after BMT. On day 9, as he developed dark-brown colored urine with prominent elevation of