The B-cell side of Allergy and Chronic Inflammatory Disease: Studies on the source of IgE and IgG4

In allergic disease, IgE is the antibody which can bind to non-pathogenic allergens such as pollens, house dust mite or peanut epitopes and thereby elicits the allergic reaction. Although serum IgE has been widely used in the diagnosis of allergic disease, still very little is known about the cells producing IgE as these are scarce and difficult to detect. A small subset of B-lymphocytes, i.e. memory B cells, express surface IgE and terminally differentiated B-cells, plasma cells, can secrete IgE. In this thesis, we developed new assays to examine IgE+ B cells and plasma cells in cellular and molecular detail, and assessed how these were different between healthy individuals and patients with allergic disease. Moreover, we adapted these assays to assess IgG4-expressing B cells, as this IgG4 isotype is associated with amelioration of allergic disease following immunotherapy, while also a being a major disease marker in patients with the chronic inflammatory condition IgG4-related disease (IgG4-RD)