Minami Yamada

A Distinct Function of STAT Proteins in Erythropoietin Signal Transduction

The Janus kinase (JAK)-signal transducers and activators of transcription (STAT) pathway is an important signaling pathway of interferons and cytokines. We examined the activation of STAT proteins induced by interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), or erythropoietin (EPO) using the human leukemia cell line, UT-7, which requires these cytokines for growth. IL-3, GM-CSF, and EPO induced DNA-binding activity to the oligonucleotides corresponding to the sis-inducible elements (SIE) of c-fos, in addition to the β-casein promoter (β-CAP), SIE- and β-CAP-binding proteins were identical to Stat1α and Stat3 complex and to Stat5 protein, respectively. This indicates that IL-3, GM-CSF, and EPO commonly activated Stat1α, Stat3, and Stat5 proteins in UT-7. However, EPO hardly activated Stat1α and Stat3 in UT-7/GM, which is a subline of UT-7 that grows slightly in response to EPO. Transfection studies revealed that UT-7/GM cells constitutively expressing Stat1α, but not Stat3, can grow as well in response to EPO as GM-CSF, suggesting that Stat1α is involved in the EPO-induced proliferation of UT-7. Thus, although Stat1α, Stat3, and Stat5 proteins are activated by GM-CSF, IL-3, and EPO, our data suggest that each STAT protein has a distinctive role in the actions of cytokines.

Allogeneic hematopoietic stem cell transplant following chemotherapy containing L-asparaginase as a promising treatment for patients with relapsed or refractory extranodal natural killer/T cell lymphoma, nasal type

The prognosis of advanced extranodal NK/T cell lymphoma (ENKTL) is poor. Allogeneic hematopoietic stem cell transplant (allo-HSCT) has been suggested to be a promising treatment for this disease, but its utility has yet to be established. Here we retrospectively analyzed five cases of ENKTL treated with allo-HSCT in our institute. After induction chemotherapy, disease status at allo-HSCT was second CR in three patients and refractory in two patients. All patients received a myeloablative conditioning regimen, and GVHD prophylaxis consisted of tacrolimus or cyclosporine with short-term methotrexate. Only one patient who received conventional induction chemotherapy developed severe complications, which needed long-term treatment, while others who received chemotherapy containing l-asparaginase did not have severe complications. There were no cases of treatment-related mortality, and all patients survived without disease for a median follow-up period of 1911 days. These results suggested that allo-HSCT following l-asparaginase-containing induction chemotherapy might improve the outcome of advanced ENKTL.

Acquired hemophilia A with sigmoid colon cancer : successful treatment with rituximab followed by sigmoidectomy

Acquired hemophilia A is a rare and potentially fatal condition of coagulopathy caused by autoantibodies against clotting factor VIII (factor VIII inhibitor). We report a case of a 63-year-old woman, who presented with a sudden onset of severe hemorrhagic tendency with exclusively prolonged activated partial thromboplastin time (APTT). She was diagnosed with acquired hemophilia A due to a decrease in factor VIII activity and a high titer of factor VIII inhibitor. Hemorrhage was well controlled by recombinant activated factor VII. Although the level of factor VIII inhibitor did not decline with prednisolone and cyclophosphamide, it became undetectable with rituximab. In parallel with controlling hemorrhage, malignancy, which may cause acquired hemophilia A, was searched for and sigmoid colon cancer was found. After the eradication of factor VIII inhibitor, surgical resection was performed uneventfully. Thereafter, acquired hemophilia A has been in complete remission without any additional therapy. The present case suggests the efficacy of rituximab for refractory acquired hemophilia A and the importance of the identification of underlying diseases that can cause acquired hemophilia A.

CD26, together with cell surface adenosine deaminase, is selectively expressed on ALK-positive, but not on ALK-negative, anaplastic large cell lymphoma and Hodgkin's lymphoma

CD26/dipeptidyl peptidase IV is a cell surface antigen with multiple biological functions. Although its involvement in tumor biology has been suggested, the significance of its expression in malignant lymphoma has not been clarified in detail. This study examined the expression of CD26 and cell surface adenosine deaminase (ADA) in 42 cases of Hodgkins lymphoma (HL) and T-cell lymphoma by immunohistochemistry on frozen sections. CD26 was expressed in three of 14 cases of HL, in four of eight cases of anaplastic large cell lymphoma (ALCL), in two of nine cases of peripheral T-cell lymphoma, in one of six cases of lymphoblastic lymphoma and in none of three cases of adult T-cell lymphoma/leukemia. Expression of cell surface ADA was fully correlated with the expression of CD26 and expression of CD26/ADA in ALCL and HL was also completely correlated with the expression of p80 and epithelial membrane antigen. Of 10 CD26-positive patients, seven had fever and elevated CRP at initial diagnosis and over a median follow-up of 61 months (range, 7 – 152 months) only three survived. This study suggested that CD26 is selectively expressed on ALK-positive, but not on ALK-negative, ALCL and HL. This is also the first report to demonstrate that ADA is coexpressed with CD26 on the cell surface of malignant neoplasms in vivo.

Autoimmune neutropenia in pregnant women causing neonatal neutropenia

Autoimmune neutropenia (AIN) can occur during pregnancy. However, neonatal neutropenia occurring in an infant born to a mother with AIN has only rarely been documented. Recently, we have experienced two cases of AIN during pregnancy, both of which caused severe yet transient neonatal neutropenia (< 0·3 × 109/l), probably as a result of transplacental maternal anti‐neutrophil autoantibodies. The anti‐neutrophil antibodies seemed to be against antigens other than NA1/NA2 because the autoantibodies did not bind to neutrophils of specific NA types selectively in the granulocyte indirect immunofluorescence test. Although AIN is a relatively uncommon disease, neonatal neutropenia caused by maternal AIN may not be quite as rare.

Clonal evolution from trisomy into tetrasomy of chromosome 8 associated with the development of acute myeloid leukemia from myelodysplastic syndrome

Tetrasomy 8, though rare, is usually associated with trisomy 8, a far more common chromosomal abnormality in acute myeloid leukemia (AML). Yet the clonal relationship between trisomy 8 and tetrasomy 8 in the cases with these chromosomal abnormalities has been unclear. Here, we report a case of a 17-year-old male, diagnosed as having a myelodysplastic syndrome (MDS). Chromosome analysis showed the presence of trisomy 8. Five years later, he developed overt AML exhibiting tetrasomy 8 only. After chemotherapy, the blast cells in the bone marrow decreased to 3.4%, and the karyotype showed trisomy 8 alone. Fluorescence in situ hybridization using a probe specific for chromosome 8 showed that the percentages of cells exhibiting 2/ 3 /4 signals were 7.8/89.2/2.0 at the MDS stage, 20.5/36.1/41.0 when overt AML developed and 24.0/72.1/2.4 after chemotherapy. These results suggested that tetrasomy 8 is derived from the AML clone, possibly evolved from the MDS clone with trisomy 8. To our knowledge, this is the first detailed case report of clonal evolution from trisomy 8 into tetrasomy 8 associated with the development of AML from MDS.

Expression analyses and transcriptional regulation of mouse nucleolar spindle-associated protein gene in erythroid cells: essential role of NF-Y.

Nucleolar spindle‐associated protein (NuSAP), a recently characterised microtubule‐associated protein, appears to participate in cell cycle regulation. It has been demonstrated that NuSAP is expressed preferentially in the erythroid lineage in haematopoietic cells. To characterise its role in erythropoiesis, we examined the expression profile of the NuSAP gene. In fractionated murine erythroblasts, NuSAP mRNA was remarkably more abundant in the subset corresponding to immature erythroblasts (TER119+CD71high) than mature erythroblasts (TER119+CD71low), and it was significantly increased in TER119+ cells from in vivo phlebotomised mice compared with control mice. Furthermore, during erythroid maturation of mouse erythroleukaemia (MEL) cells by dimethylsulfoxide, NuSAP mRNA was increased at 24–72 h. These results suggested that the NuSAP gene might contribute to the expansion of immature erythroblast pool. The regulatory mechanism of NuSAP gene was investigated using MEL cells. Sequence analysis revealed that NuSAP promoter has four CCAAT boxes, an Sp1 element, a GATA‐like element, a CACCC element, a Myb element and lacks a TATA box. Promoter analyses demonstrated that duplicated CCAAT boxes located at −81/−85 and −30/−34 were essential for promoter activity. Furthermore, the promoter was trans‐activated by NF‐YA through these elements. These results suggest that NuSAP might play an important role in erythroid proliferation under the control of NF‐Y.

A retrospective analysis of bortezomib therapy for Japanese patients with relapsed or refractory multiple myeloma: β2-microglobulin associated with time to progression

Bortezomib is approved for the treatment of patients with relapsed or refractory multiple myeloma (MM), but only a few clinical studies for Japanese patients who were treated with bortezomib have been reported. We retrospectively analyzed 40 patients with relapsed or refractory MM who have received bortezomib at three collaborating centers in Miyagi prefecture in Japan. All the patients have been received bortezomib in combination with dexamethasone. Responses were determined using International Myeloma Working Group uniform response criteria. The overall response was observed in 30 patients (75%), including very good partial response in 8 patients (20%), and partial response in 22 patients (55%). The median time to disease progression was 8.7 months, and the median overall survival has not been reached. The factors affecting time to disease progression were International Staging System stage, serum β2-microglobulin level, and number of treatment cycles. The most common grade 3 and 4 adverse events were thrombocytopenia (50%), peripheral neuropathy (25%), leukopenia (25%), and herpes zoster infection (25%). Thus, bortezomib is well tolerated and effective for Japanese patients with relapsed or refractory MM. Our results suggest that serum β2-microglobulin level may be a marker of prognosis on bortezomib therapy for patients with relapsed or refractory MM although further studies are needed.

Myeloablative Cord Blood Transplantation for Adults With Hematological Malignancies Using Tacrolimus and Short-Term Methotrexate for Graft-Versus-Host Disease Prophylaxis: Single-Institution Analysis

We studied clinical outcomes of 25 adult patients with hematological malignancies who underwent cord blood transplantation (CBT) after a myeloablative conditioning regimen, including high-dose cytosine arabinoside (CA) (8 g/m(2)), cyclophosphamide (CY) (120 mg/kg), and total-body irradiation (TBI) (12 Gy). For graft-versus-host disease (GVHD) prophylaxis, all patients received a combination of tacrolimus and short-term methotrexate (sMTX). Neutrophil engraftment was achieved in 20 of 25 patients. Of the 22 evaluable patients, 2 and 7 had grades I and II acute GVHD, respectively, and only 1 developed grade III acute GVHD after discontinuation of tacrolimus due to encephalopathy. Chronic GVHD developed in 13 of 19 evaluable patients, including 4 with the extensive type. However, the Karnofsky scores of survivors at 1 year after CBT were 90% or 100%. Eight of 25 patients died of nonrelapse causes (n = 4) and relapse/progressive disease (n = 4); 17 patients are currently alive with 15 free of disease at the present time (median follow-up, 24 months). The probability of disease-free survival at 2 years among patients with standard risk was 89% and that of high-risk patients was 30%. Transplantation-related mortality within 100 days was 12%. These results suggested that the CA/CY/TBI combination is a promising conditioning regimen for myeloablative CBT. Furthermore, tacrolimus and sMTX seemed to have suppressed severe acute GVHD and chronic GVHD, which may also contribute to the favorable results.

Fludarabine- and cyclophosphamide-based nonmyeloablative conditioning regimen for transplantation of chronic granulomatous disease: possible correlation with prolonged pure red cell aplasia.

An 18-year-old patient with chronic granulomatous disease who had had at least 2 episodes of life-threatening Aspergillus pneumonia was treated with nonmyeloablative allogeneic stem cell transplantation (NSCT) from an HLA-identical and major ABO-incompatible sibling. The conditioning regimen consisted of cyclophosphamide at a dose of 60 mg/kg (days -5, -4) and fludarabine at a dose of 30 mg/m2 (days -5, -4, -3, -2, -1). Full donor T-cell engraftment was attained on day 28, and full myeloid engraftment was established by day 150 after tacrolimus withdrawal.The bacteriocidal activity of neutrophils, as indicated by flow cytometry with the use of a dichlorofluorescein diacetate oxidation assay, remained low until 150 days after transplantation, but no infection was detected, a finding that suggests mixed chimerism of granulocytes controlled infection. Graftversus-host disease and severe regimen-related toxicity (grade 3 or greater) were not observed. This patient developed prolonged pure red cell aplasia, possibly caused by persistent antidonor isohemagglutinin produced by the residual host B-cells. The aplasia resolved with the combination of erythropoietin, double filtration plasmapheresis, and rituximab. In the setting of major ABO-incompatible NSCT, a fludarabine- and cyclophosphamide-based conditioning regimen may lead to prolonged PRCA.