Amagai, Masayuki

写真a

Affiliation

President and Vice-Presidents (Mita)

Position

Vice-President

External Links
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Academic Degrees 【 Display / hide 】

  • 医学博士, Keio University, 1989.11

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Research Areas 【 Display / hide 】

  • Life Science / Dermatology

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Research Keywords 【 Display / hide 】

  • 皮膚免疫学

  • 皮膚診断学

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Books 【 Display / hide 】

  • 慶應義塾大学病院の医師100人と学病気の予習帳

    AMAGAI MASAYUKI, 講談社：東京, 2017.02

    Scope: 186

  • 臨床検査データブック2017-2018

    AMAGAI MASAYUKI, 医学書院：東京, 2017.02

    Scope: 452-453

  • 臨床検査データブック2017-2018

    AMAGAI MASAYUKI, 医学書院：東京, 2017.02

    Scope: 451-452

  • 臨床検査データブック2017-2018

    AMAGAI MASAYUKI, 医学書院：東京, 2017.02

    Scope: 452

  • Immunology of the Skin

    Yamagami, J. Takahashi, H. Amagai, M., Springer: NY, USA, 2016.04

    Scope: 405-417

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Papers 【 Display / hide 】

  • Early symptoms preceding post-infectious irritable bowel syndrome following COVID-19: a retrospective observational study incorporating daily gastrointestinal symptoms

    Yamamoto R., Yamamoto A., Masaoka T., Homma K., Matsuoka T., Takemura R., Wada M., Sasaki J., Kanai T., Amagai M., Saya H., Nishihara H.

    BMC Gastroenterology (BMC Gastroenterology)  23 ( 1 )  2023.12

    　View Summary

    Background: Intestinal microinflammation with immune dysfunction due to severe acute respiratory syndrome coronavirus 2 reportedly precipitates post-infectious irritable bowel syndrome. This study aimed to elucidate potential risk factors for subsequent development of irritable bowel syndrome, hypothesizing that it is associated with specific symptoms or patient backgrounds. Methods: This single-center retrospective observational study (2020–2021) included adults with confirmed coronavirus disease requiring hospital admission and was conducted using real-world data retrieved from a hospital information system. Patient characteristics and detailed gastrointestinal symptoms were obtained and compared between patients with and without coronavirus disease-induced irritable bowel syndrome. Multivariate logistic models were used to validate the risk of developing irritable bowel syndrome. Moreover, daily gastrointestinal symptoms during hospitalization were examined in patients with irritable bowel syndrome. Results: Among the 571 eligible patients, 12 (2.1%) were diagnosed with irritable bowel syndrome following coronavirus disease. While nausea and diarrhea during hospitalization, elevated white blood cell count on admission, and intensive care unit admission were associated with the development of irritable bowel syndrome, nausea and diarrhea were identified as risk factors for its development following coronavirus disease, as revealed by the adjusted analyses (odds ratio, 4.00 [1.01–15.84] and 5.64 [1.21–26.31], respectively). Half of the patients with irritable bowel syndrome had both diarrhea and constipation until discharge, and constipation was frequently followed by diarrhea. Conclusions: While irritable bowel syndrome was rarely diagnosed following coronavirus disease, nausea and diarrhea during hospitalization precede the early signs of irritable bowel syndrome following coronavirus disease.

  • Dissecting skin microbiota and microenvironment for the development of therapeutic strategies

    Ito Y., Amagai M.

    Current Opinion in Microbiology (Current Opinion in Microbiology)  74 2023.08

    ISSN  13695274

    　View Summary

    The skin is a pivotal barrier between the human body and the environment, and is a habitat for numerous microorganisms. While host–microbiota interactions in the skin are essential for homeostasis, disturbances in microbial composition and the abnormal growth of certain bacteria are associated with various diseases. Here, we identify strains and communities of skin commensals that contribute to or impair skin barrier function. Furthermore, we discuss the skin microenvironments suitable for specific microbiota that exert therapeutic effects and suggest focus areas for the prospective development of therapeutic strategies using bacterial agents. Finally, we highlight recent efforts to treat skin diseases associated with live bacteria.

  • Diverse Role of OX40 on T Cells as a Therapeutic Target for Skin Diseases

    Iriki H., Takahashi H., Amagai M.

    Journal of Investigative Dermatology (Journal of Investigative Dermatology)  143 ( 4 ) 545 - 553 2023.04

    ISSN  0022202X

    　View Summary

    OX40 is an important costimulatory molecule for T-cell expansion and survival. Because OX40 is expressed on most T-cell subsets, it is an attractive therapeutic target for a variety of T-cell‒mediated diseases. Clinical trials are already underway for some skin inflammatory diseases. In this review, we present various observations that improve our understanding of how OX40-targeted therapy can be applied for skin inflammatory diseases, such as atopic dermatitis and psoriasis, T helper (Th)2- and Th17-mediated diseases, respectively. The important OX40/OX40L-mediated interaction between T cells and other immune cells is also discussed in terms of skin autoimmune diseases, such as alopecia areata and pemphigus. Regulatory T cells (Tregs) highly express OX40, and the skin harbors a large Treg population; thus, understanding how OX40-targeted treatment acts on Tregs is vital for the development of therapeutic strategies for various skin diseases.

  • Clinical severity scores as a guide for prediction of initial treatment responses in pemphigus and pemphigoid patients

    Tanaka R., Kurihara Y., Egami S., Saito Y., Ouchi T., Funakoshi T., Takahashi H., Umegaki-Arao N., Kubo A., Tanikawa A., Amagai M., Yamagami J.

    Journal of Dermatology (Journal of Dermatology)  50 ( 2 ) 203 - 211 2023.02

    ISSN  03852407

    　View Summary

    Pemphigus and pemphigoid are autoimmune blistering diseases that affect mucosa and skin. Several clinical scoring systems, including the pemphigus disease area index (PDAI) and the bullous pemphigoid disease area index (BPDAI), have been validated for managing disease activity and severity. Current guidelines recommend that treatment response be evaluated with clinical scores and that additional second-line therapies be considered if initial treatment is insufficient for disease control. However, there have been few studies analyzing correlations between PDAI/BPDAI transitions and initial treatment effects. To investigate whether PDAI/BPDAI transitions during the treatment initiation phase correlate with initial treatment responses and whether such information can be used as a guide for necessary additional treatment, we retrospectively analyzed 67 pemphigus patients and 47 pemphigoid patients who received initial treatment at Keio University between 2012 and 2018. The clinical symptoms were evaluated weekly with PDAI/BPDAI. The patients were divided into two groups: in group A, disease was controlled only with oral corticosteroids and immunosuppressants (initial treatment), whereas in group B additional therapies were required due to insufficient responses. In pemphigus, the PDAI ratio of day 7/day 0 was significantly reduced in group A compared to group B (0.548 vs 0.761, P < 0.01) after initial treatment had started. In pemphigoid, the ratios of day 7/day 0 of BPDAI (erosion/blister) and BPDAI (urticaria/erythema) significantly decreased in group A compared to group B (0.565 vs 0.901 and 0.350 vs 0.760, respectively, P < 0.05). Receiver operating characteristic analyses on PDAI, BPDAI (erosion/blister) and BPDAI (urticaria/erythema) revealed that the cut-off values in the ratios of day 7/day 0 were 0.762, 0.675, and 0.568, respectively. Our results suggest that PDAI/BPDAI transitions during the initial phase of the treatments may be useful to predict the outcome of the treatment provided and the necessity of additional therapies to achieve disease control.

  • Rituximab therapy for intractable pemphigus: A multicenter, open-label, single-arm, prospective study of 20 Japanese patients

    Yamagami J., Kurihara Y., Funakoshi T., Saito Y., Tanaka R., Takahashi H., Ujiie H., Iwata H., Hirai Y., Iwatsuki K., Ishii N., Sakurai J., Abe T., Takemura R., Mashino N., Abe M., Amagai M.

    Journal of Dermatology (Journal of Dermatology)  50 ( 2 ) 175 - 182 2023.02

    ISSN  03852407

    　View Summary

    This was a multicenter clinical trial of rituximab, a chimeric monoclonal IgG antibody directed against CD20, for the treatment of refractory pemphigus vulgaris and pemphigus foliaceus. In total, 20 patients were treated with two doses of rituximab (1000 mg; 2 weeks apart) on days 0 and 14. The primary end point was the proportion of patients who achieved complete or partial remission on day 168 following the first rituximab dose. Of the 20 enrolled patients, 11 (55%) and four (20%) achieved complete and partial remission, respectively; therefore, remission was achieved in a total of 15 patients (75.0% [95% confidence interval, 50.9%–91.3%]). It was demonstrated that the remission rate was greater than the prespecified threshold (5%). In addition, a significant improvement in clinical score (Pemphigus Disease Area Index) and decrease in serum anti-desmoglein antibody level were observed over time. Four serious adverse events (heart failure, pneumonia, radial fracture, and osteonecrosis) were recorded in two patients, of which only pneumonia was considered causally related with rituximab. The level of peripheral blood CD19-positive B lymphocytes was decreased on day 28 after rituximab treatment and remained low throughout the study period until day 168. Our results confirm the efficacy and safety of rituximab therapy for refractory pemphigus in Japanese patients.

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Papers, etc., Registered in KOARA 【 Display / hide 】

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Reviews, Commentaries, etc. 【 Display / hide 】

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Presentations 【 Display / hide 】

  • 免疫チェックポイント阻害薬抵抗の進行期悪性黒色腫に対する殺細胞性抗癌剤の治療効果

    AMAGAI MASAYUKI

    第881回日本皮膚科学会東京地方会 (東京) , 

    2018.09
    , 

    Oral presentation (general)

  • 透析患者においてセクキヌマブが有効であった尋常性乾癬・関節症性乾癬の3例

    AMAGAI MASAYUKI

    第33回日本乾癬学会学術大会 (愛媛) , 

    2018.09
    , 

    Oral presentation (general)

  • 類天疱瘡を合併した尋常性乾癬の3例

    AMAGAI MASAYUKI

    第33回日本乾癬学会学術大会 (愛媛) , 

    2018.09
    , 

    Oral presentation (general)

  • アトピー性皮膚炎患者と健常人の皮膚由来黄色ブドウ球菌株の解析

    AMAGAI MASAYUKI

    第63回日本ブドウ球菌研究会 (鹿児島) , 

    2018.08
    , 

    Oral presentation (general)

  • NCSTN変異を同定したfamilial acne inversaの姉妹例

    AMAGAI MASAYUKI

    第880回日本皮膚科学会東京地方会 (東京) , 

    2018.07
    , 

    Oral presentation (general)

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Research Projects of Competitive Funds, etc. 【 Display / hide 】

  • 皮膚細菌叢と宿主の相互作用理解に基づく炎症性疾患制御法の開発

    2016.10
    -
    2022.03

    日本医療研究開発機構（AMED）CREST, Principal investigator

  • 皮膚・腸内微生物叢解析によるアトピー性皮膚炎発症機序の解明

    2016.04
    -
    2019.03

    日本医療研究開発機構（AMED）, Principal investigator

  • ステロイド治療抵抗性の天疱瘡患者を対象としたリツキシマブの医師主導治験

    2017.04
    -
    2020.03

    日本医療研究開発機構（AMED）, Principal investigator

  • 稀少難治性皮膚疾患に関する調査研究

    2017.04
    -
    2020.03

    Health and Labour Sciences Research Grants, Principal investigator

  • Dissecting mechanisms of functional cell death "corneoptosis" and stratum corneum homeostasis regulated by pH and its clinical application

    2022.04
    -
    2028.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, 基盤研究(S), Principal investigator

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Works 【 Display / hide 】

  • 河北新聞 朝刊 15面「皮膚にぺたり「極薄」電極」

    2017.09
    , 

    Other, Joint

  • 読売新聞 朝刊 25面「肌に貼れる電子回路 スポーツ・医療で応用」

    2017.08
    , 

    Other, Joint

  • 日本経済新聞 朝刊 9面「皮膚に貼り付けるシート状電極開発」

    2017.07
    , 

    Other, Joint

  • 薬事日報 朝刊 8面「極薄ナノメッシュセンサー開発 長期生体計測への応用に期待」

    2017.07
    , 

    Other, Joint

  • フジサンケイビジネスアイ 朝刊 11面「皮膚に水で貼り付け長期測定 JSTなど超軽量ナノメッシュセンサー開発」

    2017.07
    , 

    Other, Joint

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Intellectual Property Rights, etc. 【 Display / hide 】

  • 自然発症皮膚炎の新規原因因子及び皮膚疾患モデル動物

    Date applied： 特願 2012-047521  2012.03 

    Date announced： 特開2013-179920  2013.09 

    Date issued： 特許第5959235号  2016.07

    Patent, Joint

  • 毛乳頭細胞の培養方法

    Date applied： PCT/JP2009/063920  2009.08 

    Date announced： WO2010/021245  2010.02 

    Patent, Joint

  • アレルギー疾患モデル動物

    Date applied： 特願2010-511897  2009.05 

    Date announced： WO2009/139191  2009.11 

    Date issued： 特許第5606907号  2014.09

    Patent, Joint

  • Allergic Disease Model Animals

    Date applied： PCT/JP2009/002161  2009.05 

    Date announced： WO2009/139191  2009.11 

    Date issued： US8350118  2013.01

    Patent, Joint

  • Drug Delivery to Human Tissues by Single Chain Variable Region Antibody Fragments Cloned by Phage Display

    Date applied： PCT/US2008/00288  2008.01 

    Date announced： WO/2008/085987  2008.07 

    Date issued： US2011/0200601  2011.08

    Patent, Joint

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Awards 【 Display / hide 】

  • 皆見省吾記念賞

    1990.04, 日本皮膚科学会, Partial cDNA cloning of the 230 ‐ kD mouse bullous pem- phigoid antigen by use of a human monoclonal antibase- mentmembrane zone antibody.

    Type of Award： Award from Japanese society, conference, symposium, etc.

  • JSID賞

    AMAGAI MASAYUKI, 2000.09, 日本研究皮膚科学会

    Type of Award： Award from Japanese society, conference, symposium, etc.

  • Alfred Marchionini Research Award

    Amagai Masayuki, 2002.07, World Congress of Dermatology, 自己免疫性疾患、天疱瘡の病態解明に関する一連の卓越した業績に対して贈られた

    Type of Award： International academic award (Japan or overseas)

  • Morris H Samitz Lectureship Award

    2002.11, University of Pennsylvania

    Type of Award： Other

  • William Montagna Lectureship Award

    AMAGAI MASAYUKI, 2003.05, The Society for Investigative Dermatology, Pemphigus: A simple logic behind a complex disease

    Type of Award： International academic award (Japan or overseas)

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Courses Taught 【 Display / hide 】

  • LECTURE SERIES, DERMATOLOGY

    2025

  • DERMATOLOGY: SEMINAR

    2025

  • DERMATOLOGY: PRACTICE

    2025

  • DERMATOLOGY

    2025

  • CLINICAL ONCOLOGY: SEMINAR

    2025

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Courses Previously Taught 【 Display / hide 】

  • 皮膚科学講義「皮膚科学総論・皮疹の診方」

    Keio University

    2017.04
    -
    2018.03
    , 

    Lecture, Within own ｆaculty

  • 免疫学講義「皮膚免疫」

    Keio University

    2017.04
    -
    2018.03
    , 

    Lecture

  • 大学院生主科目講義　医学特別講義「Skin as an immune organ」

    Keio University

    2017.04
    -
    2018.03
    , 

    Lecture

  • 皮膚科学講義「皮膚疾患の診断と治療・皮膚科学の今後の展望」

    Keio University

    2017.04
    -
    2018.03
    , 

    Lecture, Within own ｆaculty

  • 皮膚科学講義「水疱症」

    Keio University

    2016.04
    -
    2017.03
    , 

    Lecture, Within own ｆaculty

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Social Activities 【 Display / hide 】

  • 内閣府 日本学術会議 会員

    2017.10
    -
    2023.09

  • 内閣府 日本学術会議 連携会員

    2006.08
    -
    2017.09

  • 厚生科学審議会疾病対策部会　リウマチ・アレルギー対策委員会　 アレルギー疾患対策作業班委員

    2011.01
    -
    2012.03

  • 日本学術振興会　学術システム研究センター研究員

    2010.04
    -
    2013.03

  • 厚生労働省　難治性疾患克服研究評価委員会　小委員会委員

    2010.02
    -
    2012.02

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Memberships in Academic Societies 【 Display / hide 】

  • National Academy of Medicine

    　

  • American Dermatological Association

    　

  • 日本皮膚科学会

    　

  • 日本研究皮膚科学会

    　

  • 日本臨床皮膚科医会

    　

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