Mechanism of B cell function in elderly patients with sepsis

2015 Fiscal Year Final Research Report

• Project/Area Number: 26861519
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Emergency medicine
• Research Institution: Gifu University
• Principal Investigator: SUZUKI KODAI 岐阜大学, 医学部附属病院, 医員 (80724583)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: 敗血症 / B細胞 / 疲弊

Outline of Final Research Achievements

While B cells are known to play pivotal roles in sepsis, changes in B cell-mediated humoral immunity have not been evaluated. We aimed to investigate changes in humoral immunity caused by defective B cell function during sepsis. Blood was collected to measure B cell subtypes, serum IgM concentration, and CpG-B oligodeoxynucleotide-induced IgM production ex vivo. The fraction of CD21-/low exhausted B cells in septic patients was higher than that observed in healthy donors. Significantly, serum IgM in elderly septic patients was negatively correlated with APACHE II score. Consistently, in B cells stimulated ex vivo, both aging and sepsis induced significant reductions in supernatant IgM. Reduced immunocompetent B cells may be related to increased severity and secondary infection after sepsis, especially in the elderly. Finally, impaired humoral immunity with increased CD21-/low exhausted B cells and insufficient IgM production may be a critical immunological change in sepsis.

Free Research Field

救急・集中治療