Final answer:
The increase in IgE levels in Michael's serum is a response to exposure to an allergen. IgE binds to mast cells and upon a second exposure, the mast cells release chemical mediators that elicit an allergic reaction.
Step-by-step explanation:
IgE is an antibody that is released in response to exposure to an allergen. On first exposure, B cells produce IgE molecules that bind to mast cells. Upon a second exposure to the same allergen, the antigen binds to the IgE-primed mast cells, causing the release of chemical mediators that elicit an allergic reaction.
This increase in IgE levels is part of the body's immune response to the allergen. The release of histamine and other modulators from the mast cells leads to symptoms of allergy such as vasodilation, edema, rash, hay fever, and asthma.