Kumiko Matsui

Recurrent extramedullary relapse of acute myelogenous leukemia after allogeneic hematopoietic stem cell transplantation in a patient with the chromosomal abnormality t(8;21) and CD56-positivity

Isolated extramedullary (EM) relapse of acute myelogenous leukemia (AML) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is rare. Predisposing factors include CD56 expression and the chromosomal abnormality t(8;21). We describe an AML patient showing the chromosomal abnormality t(8;21) and CD56 expression who experienced a unique EM relapse after allo-HSCT. Approximately 10 months after allo-HSCT, he experienced relapse involving the femur and lumbar vertebrae and, subsequently, an EM relapse of the stomach. Although we administered only local radiotherapy and not systemic chemotherapy, he showed no bone marrow relapse on long-term follow-up after achieving complete hematological remission. These findings suggest that the graft-versus-leukemia effect may preferentially maintain marrow remission rather than prevent EM relapse. In addition, our findings show that extended survival is possible after EM relapse following allo-HSCT in patients with marrow hematopoiesis of donor origin, and that augmentation of the graft-versus-leukemia effect may be useful.

A Family with Hemoglobin Hirosaki

A 48-year-old man had a 30-year history of hemolytic anemia of undetermined cause. Spherocytes were not observed, osmotic fragility was normal, and red cell enzyme activities were normal. His brother and daughter also had hemolytic anemia. The brother had previously undergone splenectomy, and the anemia had been ameliorated. In the proband and daughter, no abnormal hemoglobin was apparent in the results of isoelectric focusing and DEAE anion-exchange high-performance liquid chromatography analyses. On evaluation with the isopropanol test, unstable hemoglobin was not observed in the proband but was detected in the daughter. There was also a decreased ratio of β globin/a globin chain production. Analysis of the α2 gene demonstrated the presence of a mutation (α43 [CE1] Phe → Leu), hemoglobin Hirosaki.

PKC iota facilitates insulin-induced glucose transport by phosphorylation of SNARE regulator DOC2b

Double C2 domain protein b (DOC2b), one of the synaptotagmins, has been shown to translocate to the plasma membrane, and to initiate membrane‐fusion processes of vesicles containing glucose transporter 4 proteins on insulin stimulation. However, the mechanism by which DOC2b is regulated remains unclear. Herein, we identified the upstream regulatory factors of DOC2b in insulin signal transduction. We also examined the role of DOC2b on systemic homeostasis using DOC2b knockout (KO) mice.