[Early onset of anti- erythropoietin antibody-mediated pure red cell aplasia after commencement of subcutaneous administration of epoetin-β].

We report a 73-year-old Japanese man with early onset pure red cell aplasia (PRCA) caused by subcutaneous administration of recombinant epoetin-β. Two months after the start of epoetin therapy, he developed PRCA. Anti-erythropoietin (EPO) antibody, detected in the patient's serum by enzyme immunoassay and radioimmunoprecipitation method, inhibited EPO-dependent growth of AS-E2 cells in vitro.

Oral low-dose tacrolimus therapy for refractory hemophagocytic syndrome associated with systemic lupus erythematosus.

Hemophagocytic syndrome (HPS) is an unusual disorder associated with systemic lupus erythematosus (SLE). A 64-year-old woman was admitted because of fever and urticarial vasculitis. Laboratory data revealed pancytopenia and immunological abnormalities, suggesting elevated disease activity.

[Plasma cell leukemia presenting with cleaved nuclei and a monocytoid appearance].

A 74-year-old man presented with anemia, thrombocytopenia and leukocytosis with 41% abnormal cells having cleaved and monocytoid nuclei. The bone marrow was infiltrated with 43.6% abnormal cells that were negative for peroxidase staining and positive for PAS staining.

[Vitamin K2 therapy for myelodysplastic syndrome].

Vitamin K2 is reported to induce apoptosis or differentiation of leukemic cell lines in vitro. We administered a vitamin K2 analog, menatetrenone, at 45 mg daily to 23 patients with myelodysplastic syndrome (MDS): 13 patients with RA, 2 with RARS, 6 with RAEB and 2 with RAEB-T. Good response (GR) and partial response (PR) were defined as an increase of hemoglobin concentration exceeding 2 g/dl and 1-2 g/dl without transfusion, respectively.