Isao Tawara

Isao Tawara

*This is an algorithmically generated author record based on publicly available information.

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Isao Tawara has a total of 141 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Adjuvant Weekly Paclitaxel and Trastuzumab for HER2-Positive Early-Stage Breast Cancer with Preserved Baseline LVEF: Incidence of Cardiotoxicity and Feasibility of Simplified Cardiac Surveillance

    by Akira Tsunoda, Toshiro Mizuno, Shiro Nakamori, Mizuki Ichikawa, Yasutaka Tono, Kanako Saito, Isao Tawara

    Purpose: The incidence of trastuzumab-related cardiotoxicity is low among patients receiving regimens that do not include anthracyclines. We aimed to examine whether cardiac monitoring during paclitaxel and trastuzumab therapy can be simplified in a strictly defined low-risk population. Patients and Methods: We both retrospectively and prospectively assessed the cardiotoxicity incidence among patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer treated with adjuvant paclitaxel and trastuzumab, excluding those with major cardiotoxicity risk factors such as a low baseline left ventricular ejection fraction (LVEF). First, records of patients with HER2-positive early-stage breast cancer treated during 2015– 2021 were retrospectively reviewed. Eligibility criteria were as follows: (1) weekly paclitaxel and trastuzumab followed by trastuzumab; and (2) a baseline LVEF ≥ 55%. Second, patients considered suitable for simplified monitoring were prospectively enrolled. Inclusion criteria were a baseline LVEF ≥ 60%, age ≤ 65 years, and body mass index < 30 kg/m2. Cardiac function was evaluated every 3 months by using global longitudinal strain (GLS), cardiac biomarkers, and the LVEF. Results: Sixty-six patients were included in the retrospective study. No patients developed symptomatic cardiotoxicity (95% confidence interval [CI], 0%– 5.5%). Three patients (4.5%; 95% CI, 1.5%– 12.5%) had an asymptomatic LVEF decline, and all 66 completed the treatment. In the prospective pilot cohort, 9 patients completed therapy, and none developed cardiotoxicity (95% CI, 0%– 29.9%). The median change in the LVEF at 12 months was – 5% (range, – 12% to − 3%), and that in GLS was +2.15% (– 5.5% to +8.3%). No changes in the LVEF or GLS that required treatment interruption occurred, and cardiac biomarkers remained normal. Conclusion: Among patients with HER2-positive early-stage breast cancer who received paclitaxel and trastuzumab, had a preserved baseline LVEF, and had no anthracycline exposure, the cardiotoxicity incidence was low, suggesting that cardiac monitoring may be simplified in this population.

  • New insights into JAK2 germline variant-driven stromal cell alterations and proinflammatory bone marrow niche remodeling in myeloproliferative neoplasms

    by Komei Nishimura, Ryoichi Ono, Keiki Nagaharu, Eiko Ohya, Takuya Tsuji, Makoto Ikejiri, Akihide Nakamura, Tetsuya Nosaka, Isao Tawara, Yuka Sugimoto, et al.

  • Open Access

    Evaluation of Autoimmune FVIII Inhibitor Using Clot Waveform Analysis in Emicizumab-Treated Patients

    by Shigehisa Tamaki, Hideo Wada, Naoki Shinke, Junichiro Nishiki, Ryota Sasao, Atsushi Fujieda, Takeshi Matsumoto, Isao Tawara, Teruto Hashiguchi

    Background/Objectives: Autoimmune factor VIII deficiency (AiFVIIID) is a rare disorder that causes severe bleeding. Emicizumab has recently been found to be effective in treating AiFVIIID; however, monitoring with standard coagulation tests presents challenges. Methods: Clot waveform analysis (CWA), which involves CWA-activated partial thromboplastin time (APTT), the CWA-small amount of tissue factor activation assay (sTF/FIXa), and clotting time using a small amount of thrombin (sTT), was used to both diagnose AiFVIIID and monitor emicizumab. Results: CWA-sTT reflects the residual FVIII activity in patients with AiFVIIID. Several tests were employed, including APTT, FVIII activity, CWA, mixing tests with normal plasma, FVIII inhibitor assays, and anti-FVIII antibody activity for the diagnosis of AiFVIID in three cases. However, the sensitivity of APTT reagents to AiFVIID differed between thrombocheck-APTT and APTT-SP. Emicizumab treatment was effective for major bleeding, and anti-FVIII antibody activity could be measured using CWA-sTT. Conclusions: The sensitivity of APTT reagents to AiFVIID varies. CWA-sTT may provide utility in the diagnosis of AiFVIIID. Emicizumab is useful for the treatment of AiFVIID, and anti-FVIII antibody activity can be measured even in patients treated with emicizumab.

  • Open Access

    Diagnostic and Prognostic Evaluation of Disseminated Intravascular Coagulation Using the Disseminated Intravascular Coagulation Index

    by Eri Nakano, Hideo Wada, Akitaka Yamamoto, Masaki Tomida, Yuhuko Ichikawa, Katsuya Shiraki, Motomu Shimaoka, Hideto Shimpo, Isao Tawara

    Background: Diagnostic criteria for disseminated intravascular coagulation (DIC) have been established by the Japanese Ministry of Health, Labor, and Welfare (JMHLW), the International Society of Thrombosis Hemostasis (ISTH), and the Japanese Association for Acute Medicine (JAAM). These criteria vary and are complicated, and the cutoff values differ, so a simple and rapid diagnostic approach for DIC is needed. Materials and Methods: The usefulness of the DIC index (prothrombin time-international normalized ratio [PT-INR] x D-dimer/platelet count) for diagnosing DIC and predicting outcomes in 1500 critically ill patients was assessed. Results: The PT-INR, D-dimer level, and DIC index were significantly higher in patients with DIC than in those without DIC, and their platelet count was significantly lower. Receiver operating characteristic (ROC) analyses showed that the diagnostic agreement was the highest for the JMHLW score among the three diagnostic criteria. The PT-INR, D-dimer level, DIC index, and JMHLW, ISTH overt-DIC, and modified JAAM DIC scores were significantly higher in non-survivors than in survivors, and their platelet counts were significantly lower. Although ROC analyses showed that the PT-INR, D-dimer level, platelet count, DIC index, JMHLW, ISTH overt-DIC, and modified JAAM DIC scores were related to the outcome, the cutoff values of the DIC index, and JMHLW, ISTH overt-DIC and modified JAAM DIC scores were low. Conclusions: The DIC index was highly consistent with the three diagnostic criteria for DIC and related outcomes.


  • Open Access

    Expression of Tenascin-C Is Upregulated in the Early Stages of Radiation Pneumonitis/Fibrosis in a Novel Mouse Model

    by Kazuki Omori, Akinori Takada, Yutaka Toyomasu, Isao Tawara, Chihiro Shintoku, Kyoko Imanaka-Yoshida, Hajime Sakuma, Yoshihito Nomoto

    The lung is a major dose-limiting organ for radiation therapy (RT) for cancer in the thoracic region, and the clarification of radiation-induced lung damage (RILD) is important. However, there have been few reports containing a detailed comparison of radiographic images with the pathological findings of radiation pneumonitis (RP)/radiation fibrosis (RF). We recently reported the upregulated expression of tenascin-C (TNC), an inflammation-associated extracellular matrix molecule, in surgically resected lung tissue, and elevated serum levels were elevated in a RILD patient. Therefore, we have developed a novel mouse model of partial lung irradiation and studied it with special attention paid to the computed tomography (CT) images and immunohistological findings. The right lungs of mice (BALB/c) were irradiated locally at 30 Gy/1fr, and the following two groups were created. In Group 1, sequential CT was performed to confirm the time-dependent changes in RILD. In Group 2, the CT images and histopathological findings of the lung were compared. RP findings were detected histologically at 16 weeks after irradiation; they were also observed on the CT images from 20 weeks. The immunostaining of TNC was observed before the appearance of RP on the CT images. The findings suggest that TNC could be an inflammatory marker preceding lung fibrosis.


  • Open Access

    Evaluating Factor VIII Concentrates Using Clot Waveform Analysis

    by Hideo Wada, Katsuya Shiraki, Takeshi Matsumoto, Hideto Shimpo, Yumi Sakano, Hiroko Nishii, Shigehisa Tamaki, Kei Suzuki, Isao Tawara, Yoshiki Yamashita, et al.

    Background/Objectives: FVIII reagent activity varies across different assays, as well as activated partial thromboplastin time (APTT) reagents. The hemostatic ability of various FVIII reagents was examined via clot waveform analysis (CWA). Methods: APTT was measured using 12 APTT reagents, a small amount of tissue factor-induced FIX activation (sTF/FIXa) and a small amount of thrombin time (sTT) in order to examine 10 FVIII reagents and reference plasma (RP) using CWA. FVIII activity was measured using CWA-APTT, a chromogenic assay, or CWA-sTT. Results: Although the peak time (PT) and peak height (PH) of the CWA-APTT were markedly different in different FVIII reagents using several APTT reagents, the PTs of CWA-APTT were generally normal or shortened and the PHs of CWA-APTT were generally lower than those of RP. The FVIII activity varied, as evaluated using APTT, and was higher when using the CWA-sTT method than the APTT or chromogenic methods. CWA-sTT showed an elevated second peak of first DPH in all FVIII reagents, and both CWA-sTF/FIXa and CWA-sTT were enhanced using APTT reagents. Conclusions: Our evaluation of the hemostatic ability of FVIII reagents varied among APTT reagents. CWA-sTT can be used to further evaluate the hemostatic ability of an FVIII concentrate based on thrombin burst.


  • Open Access

    Bahcc1 is critical for the aberrant epigenetic program in a mouse model of MLL-ENL–mediated leukemia

    by Akihide Nakamura, Masahiro Masuya, Makoto Shinmei, Isao Tawara, Tetsuya Nosaka, Ryoichi Ono

    In leukemogenesis, genotoxic stress in hematopoietic stem and progenitor cells (HSPCs) drives individual context-dependent programs of malignant transformation. In light of the various differentiation stages of HSPCs based on a recently revised definition using CD150/CD48, our analyses showed that a subpopulation of long-term repopulating HSCs was most susceptible to MLL-ENL–mediated transformation. An analysis of the molecular mechanism identified Bromo-adjacent homology domain and coiled-coil containing 1 (Bahcc1), which encodes a reader molecule of trimethylated histone H3 lysine 27 (H3K27me3), as a candidate gene involved in distinct susceptibility to leukemic transformation. Interestingly, Bahcc1 was previously reported to be highly expressed in acute myeloid leukemia (AML) with an unfavorable prognosis, including some cases of MLL-rearranged AML. We found that MLL-ENL upregulated Bahcc1 through binding to its promoter, and that Bahcc1 was involved in MLL-ENL–mediated immortalization at least partly through repression of H3K27me3-marked Cdkn1c. Analyses using bone marrow transplantation in mice showed that depletion of Bahcc1 suppressed the leukemogenic activity of MLL-ENL. In a public database, high BAHCC1 expression was found to be associated with a poor prognosis in pediatric AML, in which BAHCC1 expression was significantly lower in MLL-AF9-AML than in other MLL-fusion-AML. These findings shed light on the distinct immortalization potential of HSPCs and suggest a novel MLL-fusion-Bahcc1 axis, which may lead to development of molecular targeted therapy against MLL-fusion–mediated leukemia.


  • Open Access

    The Evaluation of Clot Waveform Analyses for Assessing Hypercoagulability in Patients Treated with Factor VIII Concentrate

    by Takeshi Matsumoto, Hideo Wada, Katsuya Shiraki, Kei Suzuki, Yoshiki Yamashita, Isao Tawara, Hideto Shimpo, Motomu Shimaoka

    Background: Regular prophylactic therapy has become an increasingly common treatment for severe hemophilia. Therefore, hypercoagulability—a potential risk factor of thrombosis—is a cause for concern in hemophilic patients treated with a high dose of FVIII concentrate. In clot waveform analysis (CWA)-thrombin time (TT), a small amount of thrombin activates clotting factor VIII (FVIII) instead of fibrinogen, resulting in FVIII measurements using CWA-TT with a small amount of thrombin. Methods: The coagulation ability of patients treated with FVIII concentrate or emicizumab was evaluated using activated partial thromboplastin time (APTT), TT and a small amount of tissue factor-induced FIX activation assay (sTF/FIXa) using CWA. Results: The FVIII activity based on CWA-TT was significantly greater than that based on the CWA-APTT or chromogenic assay. FVIII or FVIII-like activities based on the three assays in plasma without emicizumab were closely correlated; those in plasma with emicizumab based on CWA-TT and chromogenic assays were also closely correlated. CWA-APTT and CWA-TT showed different patterns in patients treated with FVIII concentrates compared to those treated with emicizumab. In particular, CWA-TT in patients treated with FVIII concentrate showed markedly higher peaks in platelet-rich plasma than in platelet-poor plasma. CWA-APTT showed lower coagulability in hemophilic patients treated with FVIII concentrate than in healthy volunteers, whereas CWA-sTF/FIXa did not. In contrast, CWA-TT showed hypercoagulability in hemophilic patients treated with FVIII concentrate. Conclusions: CWA-TT can be used to evaluate the thrombin bursts that cause hypercoagulability in patients treated with emicizumab. Although routine APTT evaluations demonstrated low coagulation ability in patients treated with FVIII concentrate, CWA-TT showed hypercoagulability in these patients, suggesting that the evaluation of coagulation ability may be useful when using multiple assays.


  • Open Access

    The Evaluation of the FVIII Activity and Hypercoagulability in Patients Treated With FVIII Concentrate Using a Clot Waveform Analysis

    by Takeshi Matsumoto, Hideo Wada, Katsuya Shiraki, Kei Suzuki, Yoshiki Yamashita, Isao Tawara, Hideto Shimpo, Motomu Shimaoka

    Background: Although the use of regular replacement therapy including emicizumab for severe hemophilia has been spread, the assessment of the hemostatic ability using routine activated partial thromboplastin time (APTT) is still difficult in patients being treated with emicizumab. Methods: The hemostatic ability in patients treated with FVIII concentrate or emicizumab was evaluated by APTT, thrombin time (TT) and a small amount of tissue factor induced FIX activation assay (sTF/FIXa) using a clot waveform analysis (CWA). Results: FVIII activities based on a CWA-TT were significantly higher than those based on a CWA-APTT or chromogenic assay. FVIII activities based on the three assays in plasma without emicizumab were closely correlated, and those in plasma with emicizumab based on a CWA-TT and chromogenic assays were also closely correlated. The CWA-APTT and CWA-TT showed different patterns in patients treated with FVIII concentrates from those treated with emicizumab. In particular, the CWA-TT in patients treated with FVIII concentrate showed that the peak heights were significantly higher in platelet-rich plasma than in platelet-poor plasma. In plasma with approximately 16% of FVIII activity based on APTT assay from patients treated with FVIII concentrate, the peak height on the CWA-sTF/FIXa showed a higher hemostatic abilitythan normal plasma. Conclusions: The CWA-TT can measure the FVIII activity in patients treated with emicizumab. Although routine APTT evaluations demonstrate a low hemostatic ability in patients treated with FVIII concentrate, the CWA-TT and CWA-sTF/FIXa show hypercoagulability in those patients.


  • Open Access

    Discordance of light chain isotypes between serum and glomerular deposits in proliferative glomerulonephritis with monoclonal IgG deposits: a case report and review of the literature

    by Shoko Miura, Kan Katayama, Yuka Sugimoto, Fumika Tanaka, Mutsuki Mori, Daisuke Takahashi, Ryosuke Saiki, Yosuke Hirabayashi, Tomohiro Murata, Isao Tawara, et al.

    Background: Proliferative glomerulonephritis with monoclonal immunoglobulin G (IgG) deposits (PGNMID) is a disease entity with nonorganized granular glomerular deposition with monoclonal proteins of both heavy and light chains. Dysproteinemia was observed in only 30% of the patients with PGNMID. We herein report a case of PGNMID with discrepancy between serum and glomerular deposits. Case presentation: The patient was a 50-year-old man who had been followed at a local clinic due to hypertension, type 2 diabetes, hyperlipidemia, hyperuricemia, fatty liver, and obesity. Proteinuria had been noted five years previously, and he had been referred to a hematology department due to hyperproteinemia, high gamma globulin, and κ Bence-Jones protein (BJP) positivity one year previously. Bone marrow aspiration showed 5% plasma cells, and he was referred to the nephrology department to evaluate persistent proteinuria. He was hypertensive, and his estimated glomerular filtration rate was 54.2 ml/min/1.73 m2. His urinary protein level was 0.84 g/g⋅Cr. Urine and serum immunofixation showed BJP-κ type and IgG-κ type, respectively. Kidney biopsy showed an increase in mesangial cells and matrix without nodular lesions under a light microscope. Immunofluorescence microscopy showed granular deposits of IgG and C3 on the capillary wall and weak positivity for C1q. IgG3 was predominant among the IgG subclasses, and intraglomerular κ and λ staining was negative for κ and positive for λ. Direct fast scarlet staining was negative. Electron microscopy showed lumpy deposits without a fibrillar structure in the subepithelial area. Based on the above findings, a diagnosis of membranous nephropathy-type PGNMID was made. Since proteinuria increased gradually after three years of treatment with valsartan (40 mg, daily), oral prednisolone (30 mg, daily) was initiated, which led to decreased proteinuria. The dose of oral prednisolone was gradually tapered to 10 mg per day. At that time, proteinuria was 0.88 g/g⋅Cr. We found 204 cases in 81 articles in the PubMed database, among which 8 showed discrepancy in the heavy and/or light chains between serum and kidney. Conclusions: We experienced a case of membranous nephropathy-type PGNMID with discrepancy in light chains between serum and kidney that was successfully treated with oral prednisolone.