IgG vs IgE
When you talk about food allergies and some other types of allergic reactions, you may wonder why your allergologist or family doctor prescribes that you undergo tests like the IgG and IgE tests. These technical terms are actually acronyms for two different types of immunoglobulins, popularly known as antibodies. These Y-shaped fighters help fight against invading pathogens and are classified into five divisions in which IgG and IgE belong to.
The IgG immunoglobulin is probably what your common concept of an antibody is. Although they are smaller than other fighters, they are nonetheless the most in terms of numbers. This antibody is unique in the sense that it can pass through the placenta to offer fetal protection. Even after giving birth to a newborn child, IgGs are still around to help combat viral or bacterial infections. They serve as a preliminary line of defense before the immune cells will finally aid them in the immune response process.
On the contrary, the IgE immunoglobulin is located in other areas of the body like the skin, mucous membranes, and lungs. These fighters are more abundant in people who usually experience allergies. They are specifically tasked with responding to cases of pet dander allergies, fungal spore infections, and other pollen-related concerns. This also performs a vital role in helminth parasitic disorders.
If one is able to carefully monitor the levels of these immunoglobulins, a radical increase or decrease of either one may mean the presence of an ongoing pathology. IgG level increases with liver disease, rheumatoid arthritis, and malnutrition. It will decrease in the presence of some rare disorders like lymphoid aplasia, chromic lymphoblastic leukemia, Bence Jones proteinemia, and IgA myeloma. On the contrary, the IgE level elevates in the presence of eczema, asthma, anaphylactic shock, and hay fever. It diminishes in cases like hypogammaglobulinemia and congenital agammaglobulinemia.
Traditional food allergy tests focuses on the presence of purely IgE reactions, and that’s why it’s dubbed as the most common test for allergies. This can be observed almost instantly after allergen ingestion or direct contact. This type of reaction manifests with a swollen tongue and lips, abdominal bloating and pain, sudden diarrhea, and also hives although this can be accompanied by non-allergy-caused symptoms. However, most food allergies are IgG in nature and not IgE which can take place several hours after the onset of the reaction.
Summary:
1.The IgG immunoglobulin is smaller in size compared to the IgE.
2.The IgG are more in number than the IgE.
3.IgG can cross the placental barrier of pregnant mothers and can offer additional protection to the growing fetus.
4.Most food allergies are IgG in nature.
5.IgE has immediate symptoms unlike the delayed appearance in IgG reactions.