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Dive into the research topics where Rika Sakai is active.

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Featured researches published by Rika Sakai.


Bone Marrow Transplantation | 2001

Severe cardiac toxicity in hematological stem cell transplantation: predictive value of reduced left ventricular ejection fraction

Katsumichi Fujimaki; Atsuo Maruta; M Yoshida; Rika Sakai; Tanabe J; Hideyuki Koharazawa; Kodama F; S Asahina; M Minamizawa; Michio Matsuzaki; Shin Fujisawa; Heiwa Kanamori; Yoshiaki Ishigatsubo

Eighty patients receiving hematological stem cell transplantation (HCT) with a preparative regimen consisting of total body irradiation (12.5 Gy), cyclophosphamide (4000 or 4500 mg/m2), and thiotepa (400 mg/m2) were evaluated for the development of cardiac toxicity. Patients in whom the pretransplant cumulative dose of anthracycline was more than or equal to 300 mg/m2 showed a lower left ventricular ejection fraction (EF) before HCT compared to patients with less than 300 mg/m2 (0.61 ± 0.09 vs0.67 ± 0.06, P = 0.0010). Patients who had undergone more than or equal to six courses of chemotherapy showed a decreased EF before HCT compared to those after less than six courses (0.67 ± 0.05 vs0.63 ± 0.09, P = 0.03). Three of seven patients (43%) whose pretransplant EF had been less than or equal to 0.55 developed severe cardiac toxicity, characterized by congestive heart failure (CHF) compared with none of 83 patients (0%) whose pretransplant EF had been more than 0.55 (P = 0.00026). Of the three patients who developed severe cardiac toxicity, two were given more than 300 mg/m2 of cumulative anthracycline and underwent 23 courses and six courses of chemotherapy, while the other patient received only two courses of chemotherapy with a total dose of 139 mg/m2 of anthracycline. These results indicate that an increased cumulative dose of anthracycline and number of chemotherapy treatments are correlated with a decrease of the EF and that the EF before HCT is useful for predicting the risk of cardiac complications for recipients who have received chemotherapy. Bone Marrow Transplantation (2001) 27, 307–310.


Leukemia & Lymphoma | 2000

Predictive Factors for Central Nervous System Involvement in Non-Hodgkin's Lymphoma: Significance of Very High Serum LDH Concentrations

Naoto Tomita; Fumio Kodama; Rika Sakai; Hideyuki Koharasawa; Michiko Hattori; Jun Taguchi; Hiroyuki Fujita; Juichi Tanabe; Shin Fujisawa; Hitoshi Fukawa; Hiroshi Harano; Heiwa Kanamori; Hiroko Miyashita; Michio Matsuzaki; Koji Ogawa; Sigeki Motomura; Atsuo Maruta; Yoshiaki Ishigatsubo

Factors predictive for central nervous system (CNS) involvement at presentation were investigated in 152 patients with non-Hodgkins lymphoma (NHL) except for lymphoblastic cell lymphoma and small noncleaved cell lymphoma. Twelve patients developed CNS involvement during their disease course. The incidence was 7.9% of all the patients studied and 17.0% of the patients with serum LDH concentration two times the upper limit of normal (2N). By univariate analysis, stage IV disease (P =. 023), a serum LDH concentration S2N (P =. 009), and bone marrow involvement (P =. 016) were risk factors for CNS involvement. Multivariate logistic regression analysis identified a serum LDH concentration 2 N (P =. 032) as an independent predictor for CNS involvement. All 12 patients who developed CNS involvement were among the 126 patients with diffuse lymphoma, whereas none of the 17 patients with follicular lymphoma developed CNS involvement, although the difference was not statistically significant. The median survival of the patients with CNS involvement was only 4.5 months. We conclude that a serum LDH concentration 2N at presentation is a significant predictive factor for CNS involvement for NHL patients without lymphoblastic lymphoma and small noncleaved cell lymphoma. Therefore, we would suggest that CNS prophylaxis should be considered for patients with a serum LDH concentration 2N at presentation and diffuse lymphoma once a complete remission is achieved.


Biology of Blood and Marrow Transplantation | 2011

Long-Term Outcome of Human Herpesvirus-6 Encephalitis after Allogeneic Stem Cell Transplantation

Rika Sakai; Heiwa Kanamori; Kenji Motohashi; Wataru Yamamoto; Shiro Matsuura; Atsuko Fujita; Rika Ohshima; Hideyuki Kuwabara; Masatsugu Tanaka; Hiroyuki Fujita; Atsuo Maruta; Yoshiaki Ishigatsubo; Shin Fujisawa

Human herpesvirus-6 (HHV-6) encephalitis is recognized as a relatively rare, but sometimes lethal, complication of allogeneic hematopoietic stem cell transplantation (HSCT). Although the development of new diagnostic techniques and antiviral therapy has improved, the prognosis of encephalitis is still unclear. We surveyed 197 patients who underwent allogeneic HSCT between January 2004 and March 2008 at our institution, and 8 (4.0%) were diagnosed as having HHV-6 encephalitis. Five were male and 3 were female, with a median age of 40.5 years. The median onset of HHV-6 encephalitis was 18 days after HSCT, and the median duration of antiviral therapy was 41 days. The median survival time from the onset of encephalitis was 23.1 months (range: 2.7-66.7), and 3 patients died of unrelated causes (sepsis in 2 and gastrointestinal tract bleeding in 1). Cord blood transplantation was identified as the only independent risk factor (relative risk [RR] = 4.98; P = .049) by multivariate analysis. There was no statistical significance of survival after HSCT between the patients with HHV-6 encephalitis and those without HHV-6 encephalitis (the 2-year survival rate was 60% and 52.6%, respectively; P = .617). Four of the 5 surviving patients were unable to return to society because of neuropsychological disorders, including anterograde amnesia and seizures with prominent hippocampal atrophy. Although HHV-6 encephalitis occurring after HSCT is now becoming a curable complication, its sequelae, such as neuropsychological disorders, have a marked influence on the quality of life of long-term survivors. Accordingly, it is necessary to identify risk factors for HHV-6 encephalitis and establish methods for prevention of this complication.


Clinical Infectious Diseases | 2015

Monitoring of Hepatitis B Virus (HBV) DNA and Risk of HBV Reactivation in B-Cell Lymphoma: A Prospective Observational Study

Shigeru Kusumoto; Yasuhito Tanaka; Ritsuro Suzuki; Takashi Watanabe; Masanobu Nakata; Hirotaka Takasaki; Noriyasu Fukushima; Takuya Fukushima; Yukiyoshi Moriuchi; Kuniaki Itoh; Kisato Nosaka; Ilseung Choi; Masashi Sawa; Rumiko Okamoto; Hideki Tsujimura; Toshiki Uchida; Sachiko Suzuki; Masataka Okamoto; Tsutomu Takahashi; Isamu Sugiura; Yasushi Onishi; Mika Kohri; Shinichiro Yoshida; Rika Sakai; Minoru Kojima; Hiroyuki Takahashi; Akihiro Tomita; Dai Maruyama; Yoshiko Atsuta; Eiji Tanaka

BACKGROUND There is no standard management of reactivation of hepatitis B virus (HBV) infection in HBV-resolved patients without hepatitis B surface antigen (HBsAg), but with antibodies against hepatitis B core antigen and/or antibodies against HBsAg (anti-HBs). METHODS We conducted a prospective observational study to evaluate the occurrence of HBV reactivation by serial monthly monitoring of HBV DNA and to establish preemptive therapy guided by this monitoring in B-cell non-Hodgkin lymphoma (B-NHL) treated with rituximab plus corticosteroid-containing chemotherapy (R-steroid-chemo). The primary endpoint was the incidence of HBV reactivation defined as quantifiable HBV DNA levels of ≥ 11 IU/mL. RESULTS With a median HBV DNA follow-up of 562 days, HBV reactivation was observed in 21 of the 269 analyzed patients. The incidence of HBV reactivation at 1.5 years was 8.3% (95% confidence interval, 5.5-12.4). No hepatitis due to HBV reactivation was observed in patients who received antiviral treatment when HBV DNA levels were between 11 and 432 IU/mL. An anti-HBs titer of <10 mIU/mL and detectable HBV DNA remaining below the level of quantification at baseline were independent risk factors for HBV reactivation (hazard ratio, 20.6 and 56.2, respectively; P < .001). Even in 6 patients with a rapid increase of HBV due to mutations, the monthly HBV DNA monitoring was effective at preventing HBV-related hepatitis. CONCLUSIONS Monthly monitoring of HBV DNA is useful for preventing HBV reactivation-related hepatitis among B-NHL patients with resolved HBV infection following R-steroid-chemo (UMIN000001299).


International Journal of Hematology | 2011

Incidence, risk factors and outcomes of bronchiolitis obliterans after allogeneic stem cell transplantation

Chiaki Nakaseko; Shinichi Ozawa; Emiko Sakaida; Miwa Sakai; Yoshinobu Kanda; Kumi Oshima; Mineo Kurokawa; Satoshi Takahashi; Jun Ooi; Takayuki Shimizu; Akira Yokota; Fumiaki Yoshiba; Katsumichi Fujimaki; Heiwa Kanamori; Rika Sakai; Takayuki Saitoh; Tohru Sakura; Atsuo Maruta; Hisashi Sakamaki; Shinichiro Okamoto

Bronchiolitis obliterans (BO) after allogeneic stem cell transplantation (allo-SCT) is a late-onset, life-threatening respiratory complication that significantly reduces a patient’s quality of life. We retrospectively analysed the incidence of and risk factors for BO in allo-SCT recipients. In 2087 patients who underwent allo-SCT between January 1994 and June 2005 and survived >90 days after transplantation, 57 patients developed BO with a 5-year cumulative incidence of 2.8%. The median time interval from transplantation to BO diagnosis was 335 days (range 83–907 days). The 5-year cumulative incidence of BO was 1.62% in bone marrow transplantation (BMT) from related donors, 3.83% in peripheral blood stem cell transplantation (PBSCT) from related donors (R-PBSCT), 2.91% in BMT from unrelated donors and 2.65% in unrelated cord blood transplantation. The incidence of BO after R-PBSCT was significantly higher than that after any other type of allo-SCT (p = 0.02). R-PBSCT (p = 0.019) and preceding chronic graft-versus-host disease (GVHD) (p < 0.001) were BO-associated risk factors. Overall 5-year survival of patients with BO from the time of diagnosis was 45.4%, significantly less than those without (77.5% from day 335, p < 0.001). R-PBSCT recipients with existent chronic GVHD have a high risk of developing BO, and need extensive care and repeated pulmonary function tests.


European Journal of Haematology | 2014

Peripheral blood absolute lymphocyte/monocyte ratio as a useful prognostic factor in diffuse large B-cell lymphoma in the rituximab era

Reina Watanabe; Naoto Tomita; Megumi Itabashi; Daisuke Ishibashi; Eri Yamamoto; Satoshi Koyama; Kazuho Miyashita; Hiroyuki Takahashi; Yuki Nakajima; Yukako Hattori; Kenji Motohashi; Hirotaka Takasaki; Rika Ohshima; Chizuko Hashimoto; Etsuko Yamazaki; Katsumichi Fujimaki; Rika Sakai; Shin Fujisawa; Shigeki Motomura; Yoshiaki Ishigatsubo

The tumor microenvironment, including tumor‐infiltrating lymphocytes and myeloid‐derived cells, is an important factor in the pathogenesis and clinical behavior of malignant lymphoma. However, the prognostic significance of peripheral lymphocytes and monocytes in lymphoma remains unclear.


Leukemia Research | 2012

Clinical significance of minimal residual disease detected by multidimensional flow cytometry: Serial monitoring after allogeneic stem cell transplantation for acute leukemia

Takuya Miyazaki; Hiroyuki Fujita; Katsumichi Fujimaki; Takeshi Hosoyama; Reina Watanabe; Takayoshi Tachibana; Atsuko Fujita; Kenji Matsumoto; Masatsugu Tanaka; Hideyuki Koharazawa; Jun Taguchi; Naoto Tomita; Rika Sakai; Shin Fujisawa; Heiwa Kanamori; Yoshiaki Ishigatsubo

We analyzed minimal residual disease (MRD) by multidimensional flow cytometry (MFC) after allogeneic stem cell transplantation in 41 patients with acute myeloid leukemia (AML) (n=31) or acute lymphoblastic leukemia (ALL) (n=10). Aberrant antigen expression was compared with the results of quantitative PCR for WT1 mRNA (n=41) and leukemia-specific fusion transcripts (n=12; AML in seven, ALL in five). There was a significant correlation between detection of MRD by MFC and WT1 mRNA, as well as between MFC and fusion transcripts. Serial monitoring of MRD by the three techniques correlated in parallel to the clinical course in most of the patients, but three patients were only positive for WT1 during hematological remission. The overall survival time of patients with complete remission was significantly associated with the appearance of aberrant expression after transplantation. In conclusion, MFC is valuable for clinical management decisions after transplantation.


International Journal of Hematology | 2011

Pretransplant serum ferritin is associated with bloodstream infections within 100 days of allogeneic stem cell transplantation for myeloid malignancies

Takayoshi Tachibana; Masatsugu Tanaka; Hirotaka Takasaki; Ayumi Numata; Satomi Ito; Reina Watanabe; Rie Hyo; Rika Ohshima; Maki Hagihara; Rika Sakai; Shin Fujisawa; Naoto Tomita; Hiroyuki Fujita; Atsuo Maruta; Yoshiaki Ishigatsubo; Heiwa Kanamori

We retrospectively studied the association between iron overload and bloodstream infections (BSI) in the 100-day period following allogeneic hematopoietic stem cell transplantation (allo-HSCT) for acute myeloid leukemia or myelodysplastic syndromes. Serum ferritin was measured before transplantation to evaluate iron overload. Of 114 adult patients who underwent transplantation between 2000 and 2008, 36 (32%) developed BSI. Of the 44 isolates, 63% were Gram-positive bacteria, 32% were Gram-negative bacteria, and 4% were fungi. The median time to the onset of the first BSI was day 28 (range day 0–95) after transplantation. Univariate analysis revealed a significantly higher incidence of BSI in the high (≥1,000 ng/ml, n = 57) than in the low (<1,000 ng/ml, n = 57) ferritin group (42.1 versus 21.1%, respectively, P = 0.017). Peripheral blood stem cell transplantation (PBSCT) (n = 23) showed a greater protective effect against BSI compared with bone marrow (n = 71) and cord blood (n = 20) transplantation. Pretransplantation serum ferritin (HR = 2.844, 95% CI: 1.180–6.859, P = 0.020) and PBSCT (HR = 0.135, 95% CI: 0.025–0.717, P = 0.019) were significant factors on multivariate analysis. In conclusion, pretransplantation serum ferritin significantly predicts BSI within the 100-day period after allo-HSCT.


Hematological Oncology | 2009

The therapeutic effect of rituximab on CD5-positive and CD5-negative diffuse large B-cell lymphoma

Rie Hyo; Naoto Tomita; Kengo Takeuchi; Tomohiro Aoshima; Atsuko Fujita; Hideyuki Kuwabara; Chizuko Hashimoto; Sachiya Takemura; Jun Taguchi; Rika Sakai; Hiroyuki Fujita; Shin Fujisawa; Koji Ogawa; Shigeki Motomura; Ritsuro Suzuki; Yoshiaki Ishigatsubo

The prognosis of diffuse large B‐cell lymphoma (DLBCL) has improved markedly in recent years of rituximab era. The prognosis of de novo CD5‐positive DLBCL is reported to be poor, but the effect of rituximab on this type of lymphoma remains unclear. To investigate the effect of rituximab on CD5‐positive DLBCL, we collected DLBCL patients and analysed prognostic factors. A total of 157 patients with DLBCL who were immunophenotyped with flow‐cytometry (FCM) and treated with chemotherapy were subjected to analysis. Those treated with radiotherapy alone or with supportive therapy only were not included. Patients diagnosed in 2003 or later were treated with rituximab combined chemotherapy. There were 95 males and 62 females. Their age ranged from 20 to 91 years old, and the median was 65 years. Nineteen patients were diagnosed as having de novo CD5‐positive DLBCL. Rituximab was given alongside chemotherapy in 85 patients. Of these, 11 were positive for CD5 and 74 were negative. The addition of rituximab improved the overall survival (OS) of DLBCL patients (2‐year OS: 82% vs. 70%, p = 0.01). For CD5‐negative DLBCL, patients treated with rituximab showed 2‐year OS of 84%, which was significantly better than those treated without rituximab (70%, p = 0.008). However, for CD5‐positive DLBCL, the prognosis was not statistically different between the patients treated with and without rituximab (59% vs. 50%, p = 0.72). Although rituximab improved the prognosis of DLBCL, such improvement was restricted to the CD5‐negative group. Further investigation is required to improve the prognosis of patients with CD5‐positive DLBCL. Copyright


Modern Pathology | 2015

Genomic and immunohistochemical profiles of enteropathy-associated T-cell lymphoma in Japan

Sakura Tomita; Yara Yukie Kikuti; Joaquim Carreras; Minoru Kojima; Kiyoshi Ando; Hirotaka Takasaki; Rika Sakai; Katsuyoshi Takata; Tadashi Yoshino; Sílvia Beà; Elias Campo; Naoya Nakamura

Enteropathy-associated T-cell lymphoma (EATL) is a rare primary T-cell lymphoma of the digestive tract. EATL is classified as either Type I, which is frequently associated with and thought to arise from celiac disease and is primarily observed in Northern Europe, and Type II, which occurs de novo and is distributed all over the world with predominance in Asia. The pathogenesis of EATL in Asia is unknown. We aimed to clarify the histological and genomic profiles of EATL in Japan in a homogeneous series of 20 cases. The cases were characterized by immunohistochemistry, high-resolution oligonucleotide microarray, and fluorescence in situ hybridization (FISH) at five different loci: 1q21.3 (CKS1B), 6q16.3 (HACE1), 7p22.3 (MAFK), 9q33.3 (PPP6C), and 9q34.3 (ASS1, CARD9) using formalin-fixed paraffin-embedded sections. The histological appearance of EATL ranged from medium- to large-sized cells in 13 cases (65%), small- to medium-sized cells in five cases (25%), and medium-sized in two cases (10%). The immunophenotype was CD2+ (60%), CD3ɛ+ (100%), CD4+ (10%), CD7+ (95%), CD8+ (80%), CD56+ (85%), TIA-1+ (100%), Granzyme B+ (25%), T-cell receptor (TCR)β+ (10%), TCRγ+ (35%), TCRγδ+ (50%), and double negative for TCR (six cases, 30%). All cases were EBER−. The genomic profile showed recurrent copy number gains of 1q32.3, 4p15.1, 5q34, 7q34, 8p11.23, 9q22.31, 9q33.2, 9q34.13, and 12p13.31, and losses of 7p14.1. FISH showed 15 patients (75%) with a gain of 9q34.3 with good correlation with array comparative genomic hybridization. EATL in Japan is characterized by non-monomorphic cells with a cytotoxic CD8+ CD56+ phenotype similar to EATL Type II. The genomic profile is comparable to EATL of Western countries, with more similarity to Type I (gain of 1q and 5q) rather than Type II (gain of 8q24, including MYC). The 9q34.3 gain was the most frequent change confirmed by FISH irrespective of the cell origin of αβ-T-cells and γδ-T-cells.

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Shin Fujisawa

Yokohama City University Medical Center

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Naoto Tomita

Yokohama City University

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Heiwa Kanamori

Yokohama City University

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Atsuo Maruta

Yokohama City University

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Chizuko Hashimoto

Yokohama City University Medical Center

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