Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Jun Ichi Tamaru is active.

Publication


Featured researches published by Jun Ichi Tamaru.


Leukemia & Lymphoma | 2012

Clinicopathological analyses in patients with other iatrogenic immunodeficiency-associated lymphoproliferative diseases and rheumatoid arthritis

Michihide Tokuhira; Reiko Watanabe; Tomoe Nemoto; Morihiko Sagawa; Tatsuki Tomikawa; Jun Ichi Tamaru; Shinji Itoyama; Hayato Nagasawa; Koichi Amano; Hideto Kameda; Tsutomu Takeuchi; Shigehisa Mori; Masahiro Kizaki

Abstract Despite numerous attempts to uncover the mechanism of other iatrogenic immunodeficiency-associated lymphoproliferative diseases (OIIA-LPDs), this mechanism remains poorly understood, especially in rheumatoid arthritis (RA) patients. We analyzed the data on 23 patients with LPDs and RA. Patients were categorized into three groups according to whether they had methotrexate (MTX); MTX-regressive LPDs, MTX-persistent LPDs or other drugs-mediated LPDs. The LPDs seen in OIIA-LPDs-RA might have a unique behavior to think about several rare phenotypes. The overall survival of all patients was 74% at 5 years, and those of the three groups were 100%, 64% and 60%, respectively. Among the 6 patients who died, 4 had LPDs that were detected late, and thus adequate treatment was not given. In addition, several patients with diffuse large B cell lymphoma with a complex karyotype achieved complete remission (CR). Only one among the 17 patients who achieved CR relapsed. OIIA-LPDs-RA appeared to have a better prognosis than other more common types of lymphomas. Regarding RA treatment, various anti-RA drugs were given to the patients after developing LPDs, including MTX, but no recurrent patients were documented.


Clinical Rheumatology | 2007

Lymphomatoid granulomatosis and diffuse alveolar damage associated with methotrexate therapy in a patient with rheumatoid arthritis

Hideto Kameda; Ayumi Okuyama; Jun Ichi Tamaru; Shinji Itoyama; Atsushi Iizuka; Tsutomu Takeuchi

We report on a patient of rheumatoid arthritis (RA) who sequentially developed an axillary mass and a fatal interstitial pneumonia during a 2-year course of methotrexate (MTX) therapy. Autopsy revealed a systemic lymph node involvement and the diagnosis of Epstein–Barr virus (EBV)-related lymphoproliferative disease (LPD) with the features of lymphomatoid granulomatosis was made. The lung tissue specimens revealed a typical diffuse alveolar damage (DAD), and small nodules consisting of atypical B lymphocytes showing positive staining for EBV were sparsely recognized only in basal lungs. This is the first report of a RA patient receiving MTX therapy sequentially developing MTX-associated lymphomatoid granulomatosis and DAD.


Leukemia & Lymphoma | 2003

Consolidation radiotherapy following brief chemotherapy for localized diffuse large B-cell lymphoma: A prospective study

Kouichi Isobe; Hiroyuki Kawakami; Jun Ichi Tamaru; Shigeo Yasuda; Takashi Uno; Takashi Aruga; Tetsuya Kawata; Naoyuki Shigematsu; Kazuo Hatano; Toshiyuki Takagi; Atsuo Mikata; Hisao Ito

Abstract Many physicians administer involved field radiation therapy (RT) following brief chemotherapy for localized aggressive non-Hodgki ns lymphoma. Involved field irradiation usually implies treatment to the involved nodal regions with and without the contiguous lymphatic region, however, there is no agreements about its definition. Here we assess the appropriateness of RT irrespective of lymph node regions (localized field) following chemotherapy for patients with early stage diffuse large B-cell lymphoma. The localized field encompassed all original gross tumor volumes before chemotherapy with at least a 2- to 3-cm margin irrespective of lymphatic regions. We also evaluated the suitable radiation dose on the basis of response to chemotherapy. Twenty five eligible patients were treated with 3 cycles of chemotherapy (CHOP) followed by RT. All 25 patients had disease confined to Waldeye rs ring and/or cervical lymph nodes. Twenty two patients in complete response following chemotherapy received 30 Gy, and the remaining 3 in partial response received 40 Gy. With a median follow up of 42 months, both event free and overall survival rates at 2 years were 96.0%. There were no in-field recurrences, however, two patients experienced relapses. One developed central nervous system involvement and subsequently died of his disease. The other had mediastinal and submental lymph node relapse at 32 months, and is alive after salvage chemotherapy. Our study demonstrated that it should be possible to reduce treatment volume to less than the conventional involved field, and to limit the dose of RT in the range of 30–40 Gy.


Leukemia & Lymphoma | 2018

Clinicopathologic investigation of methotrexate-induced lymphoproliferative disorders, with a focus on regression

Michihide Tokuhira; Shuntaro Saito; Ayumi Okuyama; Katsuya Suzuki; Morihiro Higashi; Shuji Momose; Takayuki Shimizu; Takehiko Mori; Tomoe Anan-Nemoto; Koichi Amano; Shinichiro Okamoto; Tsutomu Takeuchi; Jun Ichi Tamaru; Masahiro Kizaki

Abstract Although recent accumulative data reveal the clinicopathogenesis of regression in methotrexate-induced lymphoproliferative disorders (MTX-LPDs), the precise understanding including this category remains controversial. In this study, we analyzed 62 patients with MTX-LPD. Forty-three patients showed regression (Reg group), with high rates of Hodgkin lymphoma (HL) and LPD (90 and 88%, respectively). Among the 43 patients of the Reg group, 14 patients (33%) relapsed. The median duration before relapse in the Reg group was 10.6 months. Although the difference of OS between the Reg and Non-Reg groups was not significantly different, relapse-free patients in the Reg group had a superior overall survival (OS). MTX duration had a significant impact on Epstein–Barr virus (EBV) infection (pu2009=u2009.00131). Furthermore, EBV infection was significantly related to clinical manifestations, including spleen invasion, in the regression phenomenon. Some human leukocyte antigens (HLA) alleles might affect MTX-LPD development via EBV infection, although A*2402 and DRB1*0405 might be affected as fundamental factors.


International Journal of Hematology | 2008

Severe degenerative change of multiple organs mediated by chronic active Epstein-Barr virus infection with infected T-cell expansion

Michihide Tokuhira; Atsushi Iizuka; Reiko Watanabe; Naoya Sekiguchi; Norihide Sato; Chen Kang Chien; Yasunobu Sekiguchi; Tomoe Nemoto; Kyoko Hanzawa; Jun Ichi Tamaru; Shinji Itoyama; Hiroshi Suzuki; Tsutomu Takeuchi; Shigehisa Mori; Masahiro Kizaki

We here report the case of a young Japanese woman diagnosed with chronic active Epstein–Barr virus (EBV) infection. Intensive therapy with the CHOP regimen was partially able to control virus expansion, but various central nervous system symptoms appeared and gradually progressed. EBV-encoded RNA, detected using in situ hybridization, disclosed the presence of EBV in liver and bone marrow tissue, and real-time PCR revealed the presence of EBV in the cerebrospinal fluid (CSF) and serum. CD3+CD4+CD8−CD56− T-cell expansion in the peripheral blood (PB) and CSF was also observed. Atrophic brain changes were progressive, and the patient died of central nervous system disturbance and pulmonary hemorrhage a year after diagnosis. Autopsy revealed that EBV-infected T lymphocytes with a phenotype similar to those seen in PB and CSF had infiltrated multiple organs: the lymph nodes, bone marrow, endocardium, pericardium, myocardium, spleen, liver, and spinal cord. There have been few previous reports of severe degenerative changes in the myocardium, liver, and spinal cord in patients with EBV infection. Although EBV occasionally infiltrates the central nervous system and brain, atrophic changes mediated by EBV are rare. The autopsy results of this case suggest the possibility of EBV-mediated, severe degenerative changes in multiple organs.


Journal of Hematology & Oncology | 2009

Co-existence of acute myeloid leukemia with multilineage dysplasia and Epstein-Barr virus-associated T-cell lymphoproliferative disorder in a patient with rheumatoid arthritis: a case report

Michihide Tokuhira; Kyoko Hanzawa; Reiko Watanabe; Yasunobu Sekiguchi; Tomoe Nemoto; Yasuo Toyozumi; Jun Ichi Tamaru; Shinji Itoyama; Katsuya Suzuki; Hideto Kameda; Shigehisa Mori; Masahiro Kizaki

Rheumatoid arthritis (RA) is an autoimmune disease mediated by inflammatory processes mainly at the joints. Recently, awareness of Epstein-Barr virus (EBV)-associated T-cell lymphoproliferative disorder (T-LPD) has been heightened for its association with methotraxate usage in RA patients. In the contrary, acute myeloid leukemia with multilineage dysplasia (AML-MLD) has never been documented to be present concomitantly with the above two conditions. In this report we present a case of an autopsy-proven co-existence of AML-MLD and EBV-associated T-LPD in a patient with RA.


Journal of Clinical and Experimental Hematopathology | 2015

Lymphocyte-Rich Classical Hodgkin Lymphoma::A Case with Difficulty in Distinguishing from Nodular Lymphocyte-Predominant Hodgkin Lymphoma

Jun Sakai; Ken Tanae; Naoki Takahashi; Koji Nagata; Tadashi Yoshino; Jun Ichi Tamaru; Nozomi Niitsu

A 35-year-old man was referred to our hospital because of left supraclavicular and cervical lymphadenopathies. Histopathological examination of the lymph nodes revealed reactive lymphadenopathy. He visited our hospital three years after the initial diagnosis because of enlarged left cervical lymph nodes. Histopathologically, both Hodgkin/Reed-Sternberg (H/RS) and lymphocyte-predominant (LP) cells were found in the lymph node. We first suspected nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL), because these cells were CD15(-) and CD30(-). However, the diagnosis of lymphocyte-rich classical Hodgkin lymphoma (LRCHL) was finally confirmed, because these cells were found to be CD20(-), Bob.1(+), Oct.2(-), and BCL6(-) by additional immunostaining. The patient was treated with six cycles of ABVD chemotherapy, and a complete response was achieved. However, he underwent autologous stem-cell transplantation after high-dose chemotherapy owing to a relapse 10 months after primary treatment. Distingushing LRCHL from NLPHL was difficult in this patient, because histopathological examination showed both H/RS and LP cells, and immunostaining revealed these cells to be triple negative (CD15(-), CD30(-) and CD20(-)). Accumulation of such cases are necessary to establish better criteria for the differential diagnosis and assessment of clinical behavior.


Frontiers in Immunology | 2018

Restoration of decreased T helper 1 and CD8+ T cell subsets is associated with regression of lymphoproliferative disorders developed during methotrexate treatment

Shuntaro Saito; Katsuya Suzuki; Keiko Yoshimoto; Yuko Kaneko; Kunihiro Yamaoka; Takayuki Shimizu; Takehiko Mori; Shinichiro Okamoto; Kaori Kameyama; Koichi Amano; Jun Ichi Tamaru; Michihide Tokuhira; Tsutomu Takeuchi

Background Lymphoproliferative disorder (LPD), including malignant lymphoma, is a relatively rare but life-threatening complication in RA patients under methotrexate (MTX) therapy. Spontaneous regression of LPD after MTX withdrawal is regarded as a distinct characteristic in part of such LPDs. Objective The present study aimed to investigate the immunological difference in regressive LPD and persistent LPD. Methods We studied RA patients who developed LPD during MTX administration (nu2009=u200935) and clinically matched controls (nu2009=u200935). The time of MTX cessation was defined as week 0, and LPD patients were divided into two groups according to LPD status at week 12: regressive group (nu2009=u200922) and persistent group (nu2009=u200913). Flow cytometric analysis of whole blood samples and serum cytokine assays were conducted for LPD (nu2009=u200910) and control patients (nu2009=u200910) at weeks 0, 4, and 12. Results There was a significant decrease in peripheral lymphocytes and the proportion of T helper 1 cells (Th1u2009cells), effector memory CD8+ T cells (EMCD8+ T) and Epstein–Barr virus (EBV)-specific CD8+ T cells at the time of LPD diagnosis, and a significant increase after MTX cessation was observed in the regressive group but not in the persistent group. The expansion of Th1u2009cells and EMCD8+ T cells significantly correlated with an increase in serum interferon (IFN)-γ concentration. Conclusion Changes in Th1u2009cells, EMCD8+ T cells and EBV-specific CD8+ T cells, which coincided with an increase in IFN-γ, were significantly different between regressive LPD and persistent LPD after MTX cessation.


The Journal of Rheumatology | 2007

Lymphoproliferative disorders in rheumatoid arthritis: Clinicopathological analysis of 76 cases in relation to methotrexate medication

Yoshihiko Hoshida; Jing Xian Xu; Shigeki Fujita; Itsuko Nakamichi; Jun-ichiro Ikeda; Yasuhiko Tomita; Shin-ichi Nakatsuka; Jun Ichi Tamaru; Atsushi Iizuka; Tsutomu Takeuchi; Katsuyuki Aozasa


Rheumatology | 2010

IgG4-positive multi-organ lymphoproliferative syndrome manifesting as chronic symmetrical sclerosing dacryo-sialadenitis with subsequent secondary portal hypertension and remarkable IgG4-linked IL-4 elevation

Katsuya Suzuki; Jun Ichi Tamaru; Ayumi Okuyama; Hideto Kameda; Koichi Amano; Hayato Nagasawa; Eiko Nishi; Keiko Yoshimoto; Yumiko Setoyama; Keiko Kaneko; Hisato Osada; Norinari Honda; Yasutsuna Sasaki; Shinji Itoyama; Kensei Tsuzaka; Tsutomu Takeuchi

Collaboration


Dive into the Jun Ichi Tamaru's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Shinji Itoyama

Saitama Medical University

View shared research outputs
Top Co-Authors

Avatar

Atsushi Iizuka

Saitama Medical University

View shared research outputs
Top Co-Authors

Avatar

Hideto Kameda

Saitama Medical University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Koichi Amano

Saitama Medical University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Reiko Watanabe

Saitama Medical University

View shared research outputs
Top Co-Authors

Avatar

Shigehisa Mori

Saitama Medical University

View shared research outputs
Researchain Logo
Decentralizing Knowledge