Investigation of the light chain in IgA nephropathy aiming at tailor-made medicine

• Project/Area Number: 16K19492
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Kidney internal medicine
• Research Institution: Nagasaki University
• Principal Investigator: KITAMURA Mineaki 長崎大学, 病院(医学系), 助教 (70646835)
• Research Collaborator: NISHINO Tomoya ; OBATA Yoko
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2018: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2017: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2016: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
• Keywords: IgA腎症 / 軽鎖 / 感染関連腎炎 / 上皮下deposit / 内科 / 病理学

Outline of Final Research Achievements

We examined 464 cases of IgA nephropathy diagnosed at Nagasaki University. In general, the λ chain is considered to be dominant, but the number of non-dominant cases is about 1/3 of total cases. In the case of λ chain nondominant cases, the proportion of cases with subepithelial deposits in electron microscopy, including hump-like structure, was high. Furthermore, there were many cases presenting endocapillary proliferation, which was considered to resemble the pathological features of infection-related glomerulonephritis. Cases diagnosed with IgA nephropathy are considered a heterogeneous population and treatment needs to be reviewed on a case-by-case background. Light chain staining was considered to be effective for screening for atypical IgA nephropathy, and was considered to be a tool for comprehensively suggesting the treatment method along with other pathological findings.

Academic Significance and Societal Importance of the Research Achievements

IgA腎症における軽鎖染色の意義について検討した。IgA腎症の軽鎖染色の研究が盛んに行われていた30年程前には、IgAが陽性の感染関連腎炎という概念が提唱されていなかった。今回の我々の検討では、IgA腎症と診断された症例の中でもλ鎖の染色性が弱い症例では、病歴を含めた感染関連腎炎に関する検討が必要であることを示唆しており、IgA腎症の診療における軽鎖染色の意義が高まったものと考えられる。

Research Products

• [Journal Article] Significance of subepithelial deposits in patients diagnosed with IgA nephropathy. (2019)
  • Author(s): Mineaki Kitamura
  • Journal Title: PLoS ONE Volume: 14(2) Issue: 2 Pages: e0211812-e0211812
  • DOI: 10.1371/journal.pone.0211812
  • NAID: 120006987794
  • Peer Reviewed / Open Access
• [Journal Article] IgA腎症における軽鎖染色の意義 (2017)
  • Author(s): 北村 峰昭
  • Journal Title: BIO Clinica Volume: VOL.32 No5 Pages: 77-81
• [Presentation] 上皮下高電子密度沈着物を伴うIgA腎症の臨床病理学的特徴 (2018)
  • Author(s): 北村 峰昭
  • Organizer: 日本腎臓学会
• [Presentation] IgA腎症と紫斑病性腎炎における上皮下depositについての検討 (2017)
  • Author(s): 北村 峰昭
  • Organizer: 日本腎臓学会
• [Presentation] Clinicopathological findings of IgA nephropathy with subepithelial deposits (2017)
  • Author(s): Mineaki Kitamura
  • Organizer: American society of Nephrology
  • Int'l Joint Research