The pathogenesis of IgG4-RD has yet to be fully elucidated (reviewed in (Culver and Chapman, 2016). An oligocolonal expansion of IgG4+ B-cells, plasmablasts and plasma cells suggests that particular antigens may be involved, however no single candidate has been identified. T cells are also seen in disease lesions and are necessary to support a B cell mediated response. Genetic studies have found associations between IgG4-RD and particular HLA alleles or genes with immune regulatory function.
An IgG4 response can be triggered in different scenarios, including the following:
- Repetitive antigen stimulation – when the immune system/repeated white cells come into contact with the same foreign molecule.<
- Parasitic infection.
- Exposures - dust, wood, bee keeping, garage work, and many more.
We still don't know why these can trigger IgG4 but we are gathering up as much data as possible from patients. All this information is entered and stored onto our IgG4-RD LabKey Database.