Hiromi Koiso

Interleukin-17F gene polymorphism in patients with chronic immune thrombocytopenia

Introduction:  IL‐17F is a novel inflammatory cytokine and plays an important role in some autoimmune diseases. We investigated the association between chronic ITP and the frequency of the single‐nucleotide polymorphism rs763780 (7488T/C), which causes a His‐to‐Arg substitution at amino acid 161.

Circulating plasmacytoid dendritic cells in patients with primary and Helicobacter pylori-associated immune thrombocytopenia.

Objectives:  Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by the production of autoreactive antibodies against platelet antigens. Although dysfunction of multiple aspects of cellular immunity is considered to be important in the pathogenesis of ITP, it has not been clarified which cell types play a principal role.

Interleukin-10 gene polymorphism reflects the severity of chronic immune thrombocytopenia in Japanese patients

Introduction:  T‐helper cell type 1 (Th1) polarization of the immune response has been documented in patients with chronic immune thrombocytopenia (ITP). Interleukin (IL)‐10 is the most important factor regulating Th1 and T‐helper type 2 cytokine synthesis. This study evaluated the impact of IL‐10 polymorphisms on both susceptibility to, and severity of, chronic ITP.

Quantitative analysis of Cyclin D1 and CD23 expression in mantle cell lymphoma and B-chronic lymphocytic leukemia

We studied Cyclin D1 (CyD1) and CD23 mRNA expression with real-time quantitative reverse transcription polymerase chain reaction (RQ-PCR) method. CyD1 expression in peripheral blood of seven mantle cell lymphoma (MCL) patients was found to be 1305.4 times higher than in 24 B-chronic lymphocytic leukemia (CLL) patients. CD23 expression in CLL was found to be 54.8 times higher than in MCL. These differences were statistically significant, and no overlap was found in CyD1 expression intensities between MCL and CLL. RQ-PCR allows rapid, simple and accurate quantification of CyD1 and CD23 expression, even from small samples, and is thus useful for the diagnosis of MCL and CLL.

Successful Treatment of Autoimmune Hemolytic Anemia Associated with Multicentric Castleman Disease by Anti-Interleukin-6 Receptor Antibody (Tocilizumab) Therapy

We describe herein the successful treatment of severe autoimmune hemolytic anemia (AIHA) in a patient with multicentric Castleman disease (MCD) by humanized anti-interleukin-6 (IL-6) receptor antibody (tocilizumab) therapy. Inflammatory anemia is commonly reported; however, AIHA is a very rare complication of MCD. In 1996, a 45-year-old Japanese woman was referred to our hospital because of generalized lymphadenopathy, anemia and skin eruptions. Lymph node biopsy demonstrated MCD. She was treated with prednisolone (1 mg/kg/day), which improved the anemia and skin eruptions. In 2009, she suddenly developed Coombs-positive hemolytic anemia. The blood count was as follows: hemoglobin 4.7 g/dl, platelets 490 × 109/l and white blood cell count 9.8 × 109/l. Both direct and indirect Coombs’ tests were strongly positive. She was treated with 8 mg/kg tocilizumab every 2 weeks. One month later, her hemoglobin levels rose dramatically to 10.9 g/dl and her haptoglobin level, hypergammaglobulinemia and clinical symptoms had also markedly improved. To the best of our knowledge, this is the first report of the efficacy of tocilizumab in AIHA associated with MCD. The well-established role of IL-6 in the pathogenesis of MCD may have been responsible for the improvement in the AIHA associated with MCD. Anti-IL-6 receptor antibody treatment could be an attractive therapeutic approach for AIHA associated with MCD.

Characteristic expansion of CD45RA+ CD27− CD28− CCR7− lymphocytes with stable natural killer (NK) receptor expression in NK‐ and T‐cell type lymphoproliferative disease of granular lymphocytes

We analysed the cell surface expression of chemokine receptors and natural killer receptors (NKRs) in addition to conventional T‐ and natural killer (NK)‐cell markers in patients with lymphoproliferative disease of granular lymphocytes (LDGL), and compared results between NK‐ and T‐LDGL subgroups. The subjects of this study were 15 LDGL patients: four NK‐LDGL and 11 T‐LDGL [six CD8+ T‐cell receptor (TCR) αβ+, four CD4+ TCRαβ+ and one CD8+ TCRγδ+] cases. Flow cytometric analysis showed that the expanding cells had a common phenotype, CD45RA+ CD27− CD28− CCR7−, in NK‐ and T‐LDGL patients irrespective of differences in TCR status. There were no marked differences in the expression patterns of chemokine receptors between NK‐ and T‐LDGL patients. Although restricted NKR subsets were expressed on both NK‐ and T‐large granular lymphocytes (LGLs), CD94 was the most widely expressed marker. These findings may be unique to cells of LDGL cases, because normal CD56dim NK cells frequently express killer cell immunoglobulin‐like receptors. Furthermore, analysis of NKR expression was repeated over an interval of more than 6 months, and fluctuations of NKR repertoire in the LGL clones were minimal.

Long non-coding RNA MALAT1 is an inducible stress response gene associated with extramedullary spread and poor prognosis of multiple myeloma

Extramedullary myeloma (EMM) occurs when myeloma develops outside the bone marrow; it often develops after chemotherapy and is associated with the acquisition of chemo‐resistance and a fatal course. The mechanisms underlying extramedullary spread have not yet been fully elucidated. MALAT1 is a highly abundantly and ubiquitously expressed long non‐coding RNA that plays important roles in cancer metastasis. The aims of this study were to clarify the association of MALAT1 with EMM and to elucidate the underlying mechanism of EMM formation under chemotherapeutic pressure. MALAT1 expression was significantly higher in multiple myeloma (MM) than in monoclonal gammopathy of undetermined significance. Furthermore, MALAT1 expression was markedly higher in EMM compared with that in corresponding intramedullary myeloma cells. A higher MALAT1 level was associated with shorter overall and progression‐free survival. MALAT1 expression level was positively correlated with expression of HSP90AA1, HSP90AB1 and HSP90B1 but not with TP53 expression. MALAT1 was significantly upregulated by bortezomib and doxorubicin. Considering the known functions of MALAT1, our results suggest that it acts as a stress response gene that is upregulated by chemotherapy, thereby linking chemotherapy to EMM formation. Elucidating the biological implication of long non‐coding RNA contributes to deeper understanding concerning the pathogenesis and investigation of novel therapeutic targets for MM.

Characterization of CD56+ dendritic-like cells: a normal counterpart of blastic plasmacytoid dendritic cell neoplasm?

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematological malignancy. Plasmacytoid DCs (pDCs), which are defined as lineage marker (Lin)−HLA−DR+CD56−CD123+CD11c− cells, are considered to be the normal counterpart of BPDCNs. However, BPDCN can be distinguished from pDCs by uniform expression of CD56. In this study, to identify a normal counterpart of BPDCN, we searched for a Lin−HLA−DR+CD56+ population and focused on a minor subpopulation of Lin−DR+CD56+CD123+CD11c− cells that we designated as pDC-like cells (pDLCs). pDLC constituted 0.03% of peripheral blood mononuclear cells (PBMCs), and the pDLC/pDC ratio was higher in bone marrow cells than in PBMCs. pDLC clearly expressed BDCA2, BDCA4, and myeloid antigens, which are frequently expressed by BPDCN. pDLCs exhibited modest expression of Toll-like receptors and produced less interferon-α after CpG stimulation, but presented very low endocytic ability unlike mDCs. These functional differences were attributed to the expression profile of transcriptional factors. After in vitro culture with Flt3-ligand and GM-CSF, pDLCs expressed CD11c and BDCA1. These data suggested that pDLCs are a distinct subpopulation, with an immunophenotype similar to BPDCNs. Moreover, our results indicate that pDLCs might be immature DCs and might contribute to the immunophenotypical diversity of BPDCNs.

Characterization of immunoglobulin heavy and light chain gene expression in chronic lymphocytic leukemia and related disorders.

The incidence of chronic lymphocytic leukemia is low in the Japanese population compared with populations in western countries, suggesting a role for genetic factors in the occurrence of this disease. We have previously shown that chronic lymphocytic leukemia in Japan rarely expresses the immunoglobulin heavy chain variable region (IGHV) 1‐69 gene (1 out of 43 patients, 2.3%), which is a gene most commonly expressed in chronic lymphocytic leukemia cases from western countries. In the current study, we extended the previous study by examining immunoglobulin heavy chain and light chain gene expression in 80 Japanese patients with chronic lymphocytic leukemia and in 52 Japanese patients with other leukemic chronic lymphoproliferative disorders. IGHV1‐69 gene expression was again quite low in our cohort, found in only two patients: one with chronic lymphocytic leukemia and the other with splenic marginal zone lymphoma. The IGHV4‐34 gene was most frequently expressed in chronic lymphocytic leukemia (27.5%), whereas it was rarely found in leukemic chronic lymphoproliferative disorders (7.7%, P = 0.005). There was also a significant difference in the expression of IGLV3‐21 between chronic lymphocytic leukemia and leukemic chronic lymphoproliferative disorders (29.4 vs 4.8%, P = 0.018). The IGLV3‐21 gene in the majority of chronic lymphocytic leukemia cases was associated with homologous complementarity determining region 3 sequences. Recent studies identified subsets of cases expressing almost identical B‐cell receptors. We found that two patients with chronic lymphocytic leukemia and the patient with splenic marginal zone lymphoma expressed IGHV4‐39/IGKV1‐39 and IGHV1‐69/IGKV3‐20, respectively, which belong to these subsets. (Cancer Sci 2009)

DNMT3B7 expression related to MENT expression and its promoter methylation in human lymphomas

DNA methyltransferase (DNMT) 3B7 is the most expressed DNMT3B splice variant. It was reported that the loss of DNMT3B function led to overexpression of the MEthylated in Normal Thymocyes (MENT) and accelerated mouse lymphomagenesis. We investigated the DNMT3B7 expression and its relationship to MENT expression and promoter methylation in human lymphomas. DNMT3B7 and MENT expression were significantly (p<0.0001, p<0.01) higher in lymphomas than in non-malignant. Expression of DNMT3B7 and MENT were associated with MENT promoter hypomethylation. DNMT3B7 overexpression might interfere with the normal DNA methylation mechanism required for silencing the MENT proto-oncogene, and may accelerate human lymphomagenesis.