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Dive into the research topics where Ryoko Sakai is active.

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Featured researches published by Ryoko Sakai.


The Journal of Rheumatology | 2011

Incidence and Risk Factors for Serious Infection in Patients with Rheumatoid Arthritis Treated with Tumor Necrosis Factor Inhibitors: A Report from the Registry of Japanese Rheumatoid Arthritis Patients for Longterm Safety

Yukiko Komano; Michi Tanaka; Toshihiro Nanki; Ryuji Koike; Ryoko Sakai; Hideto Kameda; Atsuo Nakajima; Kazuyoshi Saito; Mitsuhiro Takeno; Tatsuya Atsumi; Shigeto Tohma; Satoshi Ito; Naoto Tamura; Tetsuji Sawada; Hiroaki Ida; Akira Hashiramoto; Takao Koike; Yoshiaki Ishigatsubo; Katsumi Eguchi; Yoshiya Tanaka; Tsutomu Takeuchi; Nobuyuki Miyasaka; Masayoshi Harigai

Objective. To compare tumor necrosis factor-α (TNF-α) inhibitors to nonbiological disease-modifying antirheumatic drugs (DMARD) for the risk of serious infection in Japanese patients with rheumatoid arthritis (RA). Methods. Serious infections occurring within the first year of the observation period were examined using the records for patients recruited to the Registry of Japanese Rheumatoid Arthritis Patients for Longterm Safety (REAL), a hospital-based prospective cohort of patients with RA. The analysis included 1144 patients, 646 of whom were treated with either infliximab or etanercept [exposed group: 592.4 patient-years (PY)]. The remaining 498 patients received nonbiological DMARD with no biologics (unexposed group: 454.7 PY). Results. In the unexposed group, the incidence rate for all serious adverse events (SAE) was 9.02/100 PY and for serious infections, 2.64/100 PY. In the exposed group, SAE occurred in 16.04/100 PY and serious infections in 6.42/100 PY. The crude incidence rate ratio comparing serious infections in the exposed group with the unexposed group was 2.43 (95% CI 1.27–4.65), a significant increase. A multivariate analysis revealed that the use of TNF inhibitors is a significant independent risk factor for serious infection (relative risk 2.37, 95% CI 1.11–5.05, p = 0.026). Conclusion. Our study has provided the first epidemiological data on Japanese patients with RA for the safety of TNF inhibitors compared to nonbiological DMARD for up to 1 year of treatment. Anti-TNF therapy was associated with a significantly increased risk for serious infections, compared to treatment with nonbiological DMARD.


Arthritis Care and Research | 2012

Time‐dependent increased risk for serious infection from continuous use of tumor necrosis factor antagonists over three years in patients with rheumatoid arthritis

Ryoko Sakai; Yukiko Komano; Michi Tanaka; Toshihiro Nanki; Ryuji Koike; Hayato Nagasawa; Koichi Amano; Atsuo Nakajima; Tatsuya Atsumi; Takao Koike; Atsushi Ihata; Yoshiaki Ishigatsubo; Kazuyoshi Saito; Yoshiya Tanaka; Satoshi Ito; Takayuki Sumida; Shigeto Tohma; Naoto Tamura; Takahiko Sugihara; Atsushi Kawakami; Noboru Hagino; Yukitaka Ueki; Akira Hashiramoto; Kenji Nagasaka; Nobuyuki Miyasaka; Masayoshi Harigai

To investigate associations between continuous treatments with tumor necrosis factor (TNF) antagonists and risk for developing serious infections (SIs) over 3 years in Japanese patients with rheumatoid arthritis (RA) enrolled in the Registry of Japanese RA Patients for Long‐Term Safety (REAL) database.


Annals of the Rheumatic Diseases | 2012

Drug retention rates and relevant risk factors for drug discontinuation due to adverse events in rheumatoid arthritis patients receiving anticytokine therapy with different target molecules

Ryoko Sakai; Michi Tanaka; Toshihiro Nanki; Kaori Watanabe; Hayato Yamazaki; Ryuji Koike; Hayato Nagasawa; Koichi Amano; Kazuyoshi Saito; Yoshiya Tanaka; Satoshi Ito; Takayuki Sumida; Atsushi Ihata; Yoshiaki Ishigatsubo; Tatsuya Atsumi; Takao Koike; Atsuo Nakajima; Naoto Tamura; Hiroaki Dobashi; Shigeto Tohma; Takahiko Sugihara; Yukitaka Ueki; Akira Hashiramoto; Atsushi Kawakami; Noboru Hagino; Nobuyuki Miyasaka; Masayoshi Harigai

Objective To compare reasons for discontinuation and drug retention rates per reason among anticytokine therapies, infliximab, etanercept and tocilizumab, and the risk of discontinuation of biological agents due to adverse events (AE) in patients with rheumatoid arthritis (RA). Method This prospective cohort study included Japanese RA patients who started infliximab (n=412, 636.0 patient-years (PY)), etanercept (n=442, 765.3 PY), or tocilizumab (n=168, 206.5 PY) as the first biological therapy after their enrolment in the Registry of Japanese Rheumatoid Arthritis Patients for Long-term Safety (REAL) database. Drug retention rates were calculated using the Kaplan–Meier method. To compare risks of drug discontinuation due to AE for patients treated with these biological agents, the Cox proportional hazard model was applied. Results The authors found significant differences among the three therapeutic groups in demography, clinical status, comorbidities and usage of concomitant drugs. Development of AE was the most frequent reason for discontinuation of biological agents in the etanercept and tocilizumab groups, and the second most frequent reason in the infliximab group. Discontinuation due to good control was observed most frequently in the infliximab group. Compared with etanercept, the use of infliximab (HR 1.69; 95% CI 1.14 to 2.51) and tocilizumab (HR 1.98; 95% CI 1.04 to 3.76) was significantly associated with a higher risk of discontinuation of biological agents due to AE. Conclusions Reasons for discontinuation are significantly different among biological agents. The use of infliximab and tocilizumab was significantly associated with treatment discontinuation due to AE compared with etanercept.


Modern Rheumatology | 2016

Risk for malignancy in rheumatoid arthritis patients treated with biological disease-modifying antirheumatic drugs compared to the general population: A nationwide cohort study in Japan

Masayoshi Harigai; Toshihiro Nanki; Ryuji Koike; Michi Tanaka; Kaori Watanabe-Imai; Yukiko Komano; Ryoko Sakai; Hayato Yamazaki; Takao Koike; Nobuyuki Miyasaka

Abstract Objectives: To investigate and compare the risk for malignancy in rheumatoid arthritis (RA) patients treated with biologics in Japan to the general population. Methods: Data for 14,440 patients from 335 institutions who were given infliximab, etanercept, adalimumab, golimumab, tocilizumab, or abatacept were retrieved from the SafEty of biologics in Clinical Use in Japanese patients with RhEumatoid arthritis (SECURE) database. Results: We identified 333 incidents of malignancies in 320 patients during 49,320 patient-years (PY). The age- and sex-standardized incidence rate (ASR) (95% confidence interval [CI]) for overall malignancy of the SECURE cohort was 313.9/105 PY (271.4–361.3), and the standardized incidence rate ratio (SIR) (95% CI) was 0.745 (0.667–0.826). The ASR was decreased compared to the estimated incidence rate of malignancies in the Japanese general population (462.4/105 PY). The SIRs for site-specific nonhematopoietic malignancies of the SECURE cohort were not significantly elevated compared to the Japanese general population. A significant increase of SIR for malignant lymphoma (6.183, 95% CI, 4.809–7.643) was found in the SECURE cohort, similar to or slightly higher than the SIR previously reported from Japanese cohorts for RA patients. Conclusions: Continued vigilance with larger numbers of patients, longer observation periods, and inclusion of different biologics are recommended.


Arthritis Research & Therapy | 2015

Head-to-head comparison of the safety of tocilizumab and tumor necrosis factor inhibitors in rheumatoid arthritis patients (RA) in clinical practice: results from the registry of Japanese RA patients on biologics for long-term safety (REAL) registry

Ryoko Sakai; Soo-Kyung Cho; Toshihiro Nanki; Kaori Watanabe; Hayato Yamazaki; Michi Tanaka; Ryuji Koike; Yoshiya Tanaka; Kazuyoshi Saito; Shintaro Hirata; Koichi Amano; Hayato Nagasawa; Takayuki Sumida; Taichi Hayashi; Takahiko Sugihara; Hiroaki Dobashi; Shinsuke Yasuda; Tetsuji Sawada; Kazuhiko Ezawa; Atsuhisa Ueda; Kiyoshi Migita; Nobuyuki Miyasaka; Masayoshi Harigai

IntroductionThe objective of this study was to directly compare the safety of tocilizumab (TCZ) and TNF inhibitors (TNFIs) in rheumatoid arthritis (RA) patients in clinical practice.MethodsThis prospective cohort study included RA patients starting TCZ [TCZ group, n = 302, 224.68 patient-years (PY)] or TNFIs [TNFI group, n = 304, 231.01 PY] from 2008 to 2011 in the registry of Japanese RA patients on biologics for long-term safety registry. We assessed types and incidence rates (IRs) of serious adverse events (SAEs) and serious infections (SIs) during the first year of treatment. Risks of the biologics for SAEs or SIs were calculated using the Cox regression hazard analysis.ResultsPatients in the TCZ group had longer disease duration (P <0.001), higher disease activity (P = 0.019) and more frequently used concomitant corticosteroids (P <0.001) than those in the TNFI group. The crude IR (/100 PY) of SIs [TCZ 10.68 vs. TNFI 3.03; IR ratio (95% confidence interval [CI]), 3.53 (1.52 to 8.18)], but not SAEs [21.36 vs. 14.72; 1.45 (0.94 to 2.25)], was significantly higher in the TCZ group compared with the TNFI group. However, after adjusting for covariates using the Cox regression hazard analysis, treatment with TCZ was not associated with higher risk for SAEs [hazard ratio (HR) 1.28, 95% CI 0.75 to 2.19] or SIs (HR 2.23, 95% CI 0.93 to 5.37).ConclusionsThe adjusted risks for SAEs and SIs were not significantly different between TCZ and TNFIs, indicating an influence of clinical characteristics of the patients on the safety profile of the biologics in clinical practice.


Modern Rheumatology | 2016

High prevalence of cardiovascular comorbidities in patients with rheumatoid arthritis from a population-based cross-sectional study of a Japanese health insurance database

Ryoko Sakai; Fumio Hirano; Mari Kihara; Waka Yokoyama; Hayato Yamazaki; Sayoko Harada; Toshihiro Nanki; Ryuji Koike; Nobuyuki Miyasaka; Masayoshi Harigai

Abstract Objective: To reveal any association between rheumatoid arthritis (RA) and cardiovascular comorbidities using a Japanese health insurance database. Method: This population-based cross-sectional study was conducted using health insurance data provided by the Japan Medical Data Center Co., Ltd. We identified 2762 RA subjects having RA diagnostic codes (ICD10 codes; M05, M060, M062–63, M068–069) with at least two physician visits more than two months apart between June 2011 and May 2012 (RA group, n = 2762). We selected age- (±5 years), sex-, and study period-matched non-RA subjects (non-RA group, n = 27,620). We compared the prevalence of cardiovascular and related comorbidities (ischemic heart diseases [IHD], cerebral infarction, hypertension [HT], dyslipidemia [DL], and diabetes mellitus [DM]) between these groups and investigated the association between RA and cardiovascular comorbidities using a conditional logistic regression analysis. Results: The prevalence of all the investigated comorbidities in the RA group was significantly higher compared to the non-RA group. Odds ratios [95% confidence interval] of RA for IHD and cerebral infarction were 2.0 [1.5–2.5] and 3.1 [2.2–4.2] respectively, after adjusting for HT, DL, and DM. Conclusions: This study revealed for the first time in the Japanese population that RA was significantly associated with cardiovascular comorbidities.


Modern Rheumatology | 2014

A comparison of incidence and risk factors for serious adverse events in rheumatoid arthritis patients with etanercept or adalimumab in Korea and Japan

Soo-Kyung Cho; Ryoko Sakai; Toshihiro Nanki; Ryuji Koike; Kaori Watanabe; Hayato Yamazaki; Hayato Nagasawa; Yoshiya Tanaka; Atsuo Nakajima; Shinsuke Yasuda; Atsushi Ihata; Kazuhiko Ezawa; Soyoung Won; Chan-Bum Choi; Yoon-Kyoung Sung; Tae-Hwan Kim; Jae-Bum Jun; Dae-Hyun Yoo; Nobuyuki Miyasaka; Sang-Cheol Bae; Masayoshi Harigai

Abstract Objective. To compare the incidence and risk factors of serious adverse events (SAEs) in rheumatoid arthritis (RA) patients treated with etanercept (ETN) or adalimumab (ADA) between Korean and Japanese registries. Methods. We recruited 416 RA patients [505.2 patient-years (PYs)] who started ETN or ADA from Korean registry and 537 RA patients (762.0 PY) from Japanese registry. The patient background, incidence rate (IR) of SAE in 2 years, and risk factors for SAEs were compared. Results. Korean patients were younger and used more nonbiologic DMARDs, higher doses of methotrexate, and lower doses of prednisolone (PSL). The IR of SAEs (/100 PY) was higher in the Japanese registry compared to the Korean [13.65 vs. 6.73]. In both registries, infection was the most frequently reported SAE. The only significant risk factor for SAEs in Korean registry was age by decade [1.45]. In Japanese registry, age by decade [1.54], previous use of nonbiologic DMARDs ≥ 4 [1.93], and concomitant use of oral PSL ≥ 5 mg/day [2.20] were identified as risk factors for SAEs. Conclusions. The IR of SAE in Japan, especially infection, was higher than that of Korea, which was attributed to the difference of demographic and clinical characteristics of RA patients and treatment profiles.


The Journal of Rheumatology | 2015

Pneumocystis Jirovecii Pneumonia in Japanese Patients with Rheumatoid Arthritis Treated with Tumor Necrosis Factor Inhibitors: A Pooled Analysis of 3 Agents

Michi Tanaka; Ryoko Sakai; Ryuji Koike; Masayoshi Harigai

To the Editor: Pneumocystis jirovecii pneumonia (PCP) is an infectious fungal disease caused by P. jirovecii , which has attracted the attention of physicians treating patients with human immunodeficiency virus infection1, as well as those with connective tissue diseases, malignancies, and organ transplantation2. In patients with rheumatoid arthritis (RA), PCP used to be an uncommon infectious disease, but the number of case reports of PCP in patients with RA has increased since the introduction of low-dose methotrexate as an anchor drug for RA in the 1980s3. Moreover, with the introduction of anti-tumor necrosis factor (TNF) therapy, a further increase of incidence of PCP in patients with RA has been noticed, especially in Japan where strict postmarketing surveillance (PMS) programs have been conducted for patients with RA treated with TNF inhibitors4,5,6. The numbers of patients with RA with PCP in these PMS programs who were treated with infliximab (IFX), etanercept (ETN), or adalimumab (ADA) were 22 (0.4%) out of 50004, 25 (0.18%) out of 13,8945, and 25 (0.33%) out of 7469 patients6, respectively. Notably, these incidence rates of PCP in Japan are higher than the corresponding figure (0.01%) reported from the United States. Therefore, we previously analyzed the clinical characteristics and risk factors for PCP in patients with RA in Japan treated with these 3 TNF inhibitors7,8,9,10 … Address correspondence to Dr. M. Harigai, Department of Pharmacovigilance, Tokyo Medical and Dental University Graduate School, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan. E-mail: mharigai.mpha{at}tmd.ac.jp


The Journal of Rheumatology | 2015

Assessment of Risks of Pulmonary Infection During 12 Months Following Immunosuppressive Treatment for Active Connective Tissue Diseases: A Large-scale Prospective Cohort Study

Hayato Yamazaki; Ryoko Sakai; Ryuji Koike; Yasunari Miyazaki; Michi Tanaka; Toshihiro Nanki; Kaori Watanabe; Shinsuke Yasuda; Takashi Kurita; Yuko Kaneko; Yoshiya Tanaka; Yasuhiko Nishioka; Yoshinari Takasaki; Kenji Nagasaka; Hayato Nagasawa; Shigeto Tohma; Makoto Dohi; Takahiko Sugihara; Haruhito Sugiyama; Yasushi Kawaguchi; Naohiko Inase; Sae Ochi; Hiroyuki Hagiyama; Hitoshi Kohsaka; Nobuyuki Miyasaka; Masayoshi Harigai

Objective. Pulmonary infections (PI) are leading causes of death in patients with connective tissue diseases (CTD). The PREVENT study (Pulmonary infections in patients REceiving immunosuppressiVE treatmeNT for CTD) assessed risk of PI in patients with active CTD in the contemporary era of advanced immunosuppressive therapy. Methods. In patients who started corticosteroids (n = 763), conventional immunosuppressants or biologics for active CTD were enrolled. Clinical and laboratory data, usage of drugs, and occurrence of PI were collected for 12 months. Baseline risk factors were investigated using Cox regression analysis. A nested case-control (NCC) study was performed with 1:2 matched case-control pairs to assess the risk for each drug category. Results. During the observation period, 32 patients died (4.2%) and 66 patients were lost to followup (8.6%). Patients with PI (n = 61, 8%) had a significantly worse accumulated survival rate than patients without (p < 0.01). Cox hazard regression analysis using baseline data showed that these factors were significantly associated with PI: age ≥ 65 years (HR 3.87, 95% CI 2.22–6.74), ≥ 20 pack-years of smoking (2.63, 1.37–5.04), higher serum creatinine level (1.21, 1.05–1.41 per 1.0 mg/dl increase), and maximum prednisolone (PSL) dose during the first 2 weeks of treatment (2.81, 1.35–5.86 per 1.0 mg/kg/day increase). Logistic regression analysis by an NCC study revealed that maximum PSL dose within 14 days before PI (OR 4.82, 95% CI 1.36–17.01 per 1.0 mg/dl increase; 2.57, 1.28–5.16 if ≥ 0.5 mg/kg/day) was significantly associated with the events, while other immunosuppressants were not. Conclusion. Physicians should be aware of the higher risks for corticosteroids of PI than other immunosuppressants and assess these risk factors before immunosuppressive treatment, to prevent PI.


The Journal of Rheumatology | 2017

Association Between Medications and Herpes Zoster in Japanese Patients with Rheumatoid Arthritis: A 5-year Prospective Cohort Study

Sayoko Harada; Ryoko Sakai; Fumio Hirano; Nobuyuki Miyasaka; Masayoshi Harigai

Objective. To investigate the association between medications and herpes zoster (HZ) in patients with rheumatoid arthritis (RA) given biological disease-modifying antirheumatic drugs (bDMARD) or conventional synthetic DMARD in the clinical setting during 5 years using the Registry of Japanese Rheumatoid Arthritis Patients on Biologics for Longterm Safety (REAL) database. Methods. We calculated the crude incidence rate (IR) of HZ treated with systemic antiviral medications in 1987 patients from the REAL database. To estimate the association between HZ and medications, a nested case control study was performed with 1:5 case-control pairs matched for age, sex, observation start year, and comorbidity (HZ case group, n = 43; control group, n = 214). We calculated OR and 95% CI of the use of bDMARD, methotrexate (MTX), and corticosteroids for the occurrence of HZ using a conditional logistic regression analysis. Results. The median patient age was 60.0 years, female proportion was 81.5%, and median disease duration was 6.0 years. The crude IR (95% CI) of HZ was 6.66 (4.92–8.83)/1000 person-years. The OR (95% CI) of medication use were 2.28 (1.09–4.76) for tumor necrosis factor inhibitor (TNFi) and 1.13 (1.03–1.23) for oral corticosteroids dosage (per 1 mg prednisolone increment), both of which were significantly elevated. The OR of non-TNFi and MTX usage were not elevated. Conclusion. TNFi use and higher corticosteroids dosage were significantly associated with HZ in Japanese patients with RA in the clinical setting.

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Masayoshi Harigai

Tokyo Medical and Dental University

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Nobuyuki Miyasaka

Tokyo Medical and Dental University

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Ryuji Koike

Tokyo Medical and Dental University

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Hayato Yamazaki

Tokyo Medical and Dental University

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Toshihiro Nanki

Tokyo Medical and Dental University

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Michi Tanaka

Tokyo Medical and Dental University

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Fumio Hirano

Tokyo Medical and Dental University

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Kazuyoshi Saito

University of Occupational and Environmental Health Japan

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Yoshiya Tanaka

University of Occupational and Environmental Health Japan

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Kaori Watanabe

Tokyo Medical and Dental University

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