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Akio Saito,
Akihiko Yokohama,
Yohei Osaki,
Yoshiyuki Ogawa,
Hirotaka Nakahashi,
Kohtaro Toyama,
Takeki Mitsui, Yoko Hashimoto,
Hiromi Koiso,
Hideki Uchiumi,
Takayuki Saitoh,
Hiroshi Handa,
Morio Sawamura,
Masamitsu Karasawa,
Hirokazu Murakami,
Norifumi Tsukamoto,
Yoshihisa Nojima
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ABSTRACT: 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.
We enrolled 46 untreated patients with chronic ITP and 47 healthy adult volunteers, and investigated by flow cytometry the percentage and absolute number of cells in their peripheral blood that participate in the regulation of cellular immunity. These included plasmacytoid dendritic cells (pDCs), myeloid dendritic cells (mDCs), natural killer (NK) cells, natural killer T (NKT) cells, regulatory T (Treg) cells, and Th17 cells.
We found a significant reduction in the absolute number of pDCs, but not of mDCs, in patients with ITP when compared with healthy controls (P < 0.001). Reduced numbers of circulating pDCs were observed in both Helicobacter pylori (H. pylori)-positive and Helicobacter pylori (H. pylori)-negative patients with ITP. In contrast, there were no significant differences in the numbers of circulating Treg cells, Th17 cells, NK cells, or NKT cells. Interestingly, we observed increases in the number of pDCs after H. pylori eradication by antibiotics in responders but not in non-responders, while pDCs and mDCs decreased markedly after prednisolone therapy in both responders and non-responders. In patients without treatment, low pDC numbers persisted during the observational period.
We demonstrated that the number of circulating pDCs is low in patients with primary and H. pylori-associated ITP and that it changes depending on treatment modality. Further investigation is warranted with regard to the role of pDCs in the immunopathogenesis of ITP.
European Journal Of Haematology 04/2012; 88(4):340-9. · 2.61 Impact Factor
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Yoko Hashimoto,
Akihiko Yokohama,
Akio Saitoh,
Hirotaka Nakahashi,
Kohtaro Toyama,
Takeki Mitsui,
Hiromi Koiso,
Takayuki Saitoh,
Hiroshi Handa,
Hideki Uchiumi, [......],
Kayoko Murayama,
Yoshio Tamaki,
Morio Matsumoto,
Morio Sawamura,
Masamitsu Karasawa,
Hirokazu Murakami,
Junko Hirato,
Yoshihisa Nojima,
Masaru Kojima,
Norifumi Tsukamoto
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ABSTRACT: We retrospectively investigated pathological types, clinical backgrounds, treatments and prognoses in 726 adult patients with newly diagnosed malignant lymphoma in Gunma Prefecture. They consisted of 679 patients with non-Hodgkin lymphoma (B-cell type, 603; T- and NK-cell type, 76) of which 376 patients had diffuse large B-cell lymphoma (DLBCL) and 47 patients with Hodgkin lymphoma. When comparing the prognosis of DLBCL between patients receiving rituximab (R-CHOP group; n=212) and not using rituximab (CHOP group; n=126), both 3-year overall survival (73.5% vs 61.7%, p=0.010) and 3-year progression-free survival (65.1% vs 45.8%, p<0.001) were statistically better in the R-CHOP group compared to the CHOP group. Our results suggest that more than half of patients were DLBCL and the rituximab-containing regimen results in an improved prognosis for DLBCL patients.
[Rinshō ketsueki] The Japanese journal of clinical hematology 03/2012; 53(3):329-36.
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ABSTRACT: In Japan, typical hairy cell leukemia (HCL) is rare, and HCL-Japanese variant (HCL-JV) is more common. Hairy B-cell lymphoproliferative disorder (HBLD) is another unusual disorder of polyclonal B-lymphocytosis of hairy cell appearance. In the present study, we analyzed the clinical features of 3 patients with HCL, 3 with HCL-JV, and 3 with HBLD. All HBLD patients had the DRB1*04 allele. As compared with other B-cell lymphoproliferative disorders, CD27 expression on B cells was significantly lower in all patients, ranging from 0.3% to 23.4%. Our results suggest that low CD27 expression may be a distinct feature of these HCL-related disorders.
Pathology & Oncology Research 04/2009; 15(4):615-21. · 1.37 Impact Factor
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Hirotaka Nakahashi,
Norifumi Tsukamoto, Yoko Hashimoto,
Hiromi Koiso,
Akihiko Yokohama,
Takayuki Saitoh,
Hideki Uchiumi,
Hiroshi Handa,
Hirokazu Murakami,
Yoshihisa Nojima,
Masamitsu Karasawa
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ABSTRACT: 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 Science 03/2009; 100(4):671-7. · 3.33 Impact Factor
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Hirotaka Nakahashi, Yoko Hashimoto,
Arito Yamane,
Hiroyuki Irisawa,
Akihiko Yokohama,
Takayuki Saitoh,
Hiroshi Hanada,
Takafumi Matsushima,
Norifumi Tsukamoto,
Masamitsu Karasawa,
Hirokazu Murakamai,
Yoshihisa Nojima
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ABSTRACT: A 72-year-old woman was referred to our hospital for evaluation of leukocytosis revealed by a medical examination. Her physical examination demonstrated no splenomegaly and no palpable lymph nodes. Her white cell count was 10,900/microl with atypical lymphocytosis (84.5%). Her hemoglobin concentration was 10.4 g/dl, and platelet count 151,000/microl. On peripheral blood smears, the atypical lymphocytes had a hairy cell-like appearance, and phase-contrast microscopic and transmission electron microscopic findings revealed the lymphocytes had many long surface microvilli. Flowcytometric analysis of peripheral blood lymphocytes identified expanded B-lymphocytes as having the IgG+, CD5- CD10- CD11c+ CD19+ CD20+ CD23- CD25- and CD103- cell surface phenotype. Serum electrophoresis disclosed polyclonal elevation of IgG and IgM (2620 mg/dl and 840 mg/dl, respectively). No light-chain restriction and a polyclonal VH gene rearrangement pattern indicated the polyclonal proliferation of B cells. The patient was a nonsmoker and had HLA-DR4, as in previous reports which have suggested an association between hairy B-cell lymphoproliferative disorder (HBLD) and HLA-DR4. No chromosome 3 abnormality was observed. These findings were consistent with the characteristics of HBLD, but differed in some respects from those of persistent polyclonal B-cell lymphocytosis (PPBL). Therefore, we diagnosed this patient as having HBLD.
[Rinshō ketsueki] The Japanese journal of clinical hematology 09/2007; 48(8):647-51.
