Pathogenicity and antigen of IgG4 antibody in patients with IgG4 related disease

2015 Fiscal Year Final Research Report

• Project/Area Number: 26893123
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Gastroenterology
• Research Institution: Kyoto University
• Principal Investigator: Shiokawa Masahiro 京都大学, 医学(系)研究科(研究院), 医員 (50737880)
• Project Period (FY): 2014-08-29 – 2016-03-31
• Keywords: ＩｇＧ４ / 自己免疫性膵炎 / ＩｇＧ４関連疾患

Outline of Final Research Achievements

Objective: The pathogenic roles of IgGs, including IgG4, in patients with IgG4-RD remain unknown. Design: We examined the pathogenic activity of circulating IgGs in patients with IgG4-RD by injecting their IgGs into neonatal Balb/c mice. Binding of patients’ IgGs to pancreatic tissues was also analyzed in an ex vivo mouse organ culture model and in tissue samples of patients with autoimmune pancreatitis (AIP). Results: Subcutaneous injection of patients’ IgG, but not control IgG, induced pancreatic and salivary gland injuries. Pancreatic injury was also induced by injecting patients’ IgG1 or IgG4, with more destructive change induced by IgG1 than by IgG4. The potent pathogenic activity of patients’ IgG1 was significantly inhibited by simultaneous injection of patients’IgG4.
Conclusions: IgG1 and IgG4 from patients with IgG4-RD have pathogenic activities through binding to affected tissues in neonatal mice.

Free Research Field

消化器内科