The evaluation of relationship between severity of sepsis and the deposition of complement on erythrocyte in sepsis patients

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K09278
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 55060:Emergency medicine-related
• Research Institution: Kansai Medical University
• Principal Investigator: MUROYA Takashi 関西医科大学, 医学部, 講師 (20528434)
• Co-Investigator(Kenkyū-buntansha): 鍬方 安行 関西医科大学, 医学部, 教授 (50273678) ; 池側 均 関西医科大学, 医学部, 准教授 (80379198) ; 中村 文子 関西医科大学, 医学部, 助教 (80701721)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 補体 / 重症度 / 赤血球

Outline of Final Research Achievements

Twenty-one patients suffered from sepsis who were transferred to critical care center were analyzed. Their erythrocytes had more C4d deposition compared to the erythrocytes from healthy donors. The volume of C4d deposition and SOFA score, showed a loose correlation, and the results suggest that C4d deposition may predict patients’ severity. In addition, total 86 patients that included other diseases who were transferred to critical care center were analyzed. Although no statistical differences were observed in the amount of complement deposition by disease, correlations were observed with biomarkers such as serum lactate levels on admission. A slight correlation was also observed in the APACHE II score and SOFA score, which indicate the severity of the patient. Deposition of C4d on erythrocytes was shown to reflect patient severity.

Free Research Field

救急医学

Academic Significance and Societal Importance of the Research Achievements

補体成分C4dが自己の細胞である赤血球表面上に沈着していることは、補体がいちど活性化したことの足跡であると考えられる。それはまさに補体の活性化の証である。敗血症やその他の重症患者で補体が沈着していることを測定することにより、免疫の活性化の程度を定量することにつながる意義深い発見である。C4dの沈着は腎臓内の組織などの報告は多くあるが、赤血球表面上の沈着に対する報告は本邦にはごく少なく革新的であると考える。また、検体の採取という意味においても組織採取ではなく血液検査で検体が得られ、低侵襲であり患者への負担も小さく社会的に意義深いものと考えられる。