Fetal Microchimerism in Pregnancy with Systemic Lupus Erythematosus

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K17421
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 54020:Connective tissue disease and allergy-related
• Research Institution: The University of Tokyo
• Principal Investigator: Tsuchida Yumi 東京大学, 医学部附属病院, 助教 (90793597)
• Project Period (FY): 2020-04-01 – 2022-03-31
• Keywords: 全身性エリテマトーデス / 妊娠 / マイクロキメリズム

Outline of Final Research Achievements

During pregnancy, fetal cells cross the placenta and enter the maternal body, where it may persist for decades. This phenomenon is known as fetal microchimerism, and the incidence of many autoimmune diseases is higher in females compared to males, and fetal microchimerism is often presumed to be one of the possible causes for the sex difference in the incidence of autoimmune diseases. In this research, we first sought to determine the percentage of cells derived from the fetus in various immune cell subsets of peripheral blood from non-pregnant female patients. The percentage of cell expressing genes on the Y chromosome, which is presumed to reflect cells from male fetus, were high in B cells, especially CD27-IgD- B cells and IgD-CD27+ memory B cells; however, the percentages were similar between patients with autoimmune diseases compared to healthy controls. Additional investigation including the function of those chimeric cells are needed in the future.

Free Research Field

膠原病

Academic Significance and Societal Importance of the Research Achievements

本研究では、自己免疫疾患女性と健常女性の末梢血において、免疫細胞のサブセット毎での胎児性マイクロキメリズムの定量を試みた。B細胞、特にCD27-IgD-B細胞やIgD-CD27+メモリーB細胞でにおいて、マイクロキメリズムを起こしている細胞が多いことが推測された。全身性エリテマトーデスをはじめとした自己免疫疾患女性と健常女性の間で、その量についての違いは明らかでなかった。今後は、シングルセルRNAseqなどの手法を用いて、これらの細胞の機能なども含めて解析することにより、自己免疫疾患女性の妊娠における妊娠合併症の予防、妊娠に伴う減量の再燃予防などに有用な知見が得られると思われる。