Every spring, flowers bloom all across Ithaca, filling the air with a faint floral aroma. But then you walk into class and the room is filled with sniffles and sneezes as everyone’s seasonal allergies kick in. Allergies are a serious concern for many people, and the Center for Disease Control and Prevention (CDC) named allergies as the sixth highest cause of chronic illness in the US.
To understand the many causes of allergies, we first have to understand what allergies are. Allergies are caused by the immune system’s response to a foreign substance, called an allergen, even though this substance isn’t actually harmful. Common allergens include pollen, dust, and animal fur. Allergens can be inhaled, ingested, or absorbed through the skin. An allergic reaction is how our bodies respond to an allergen and can range from minor irritation to a life-threatening emergency.
Common allergic reactions like asthma, hives, and hay fever have been linked to a specific antibody called immunoglobulin E (IgE), which is produced by our body in response to an allergen. This antibody only reacts with certain allergens, meaning that someone could be allergic to one type of pollen, but not another. Once IgE is produced by the immune system, it triggers the release of histamine into the bloodstream. Histamine is a chemical that stimulates blood flow in parts of the body where the allergen is active, and causes itching, inflammation, muscle contractions, and blood vessel dilation. People experiencing an allergic reaction may take antihistamine medications, such as Benadryl, to block the effects histamine has on the body.
Many researchers are studying cells and genes within the immune system to understand why allergies occur. For instance, scientists at the Benaroya Research Institute (BRI) in Seattle are monitoring the progression of allergies and studying the immune response during allergic reactions in order to develop vaccines against allergies. Through this research, scientists at BRI have found that a special type of immune cell, called Th2A cells, play a role in all allergic reactions, regardless of the allergen. They hope to find a mechanism that will allow them to target these cells to stop allergic reactions from occurring.
Researchers at the University of Pennsylvania also had a major breakthrough in June 2023, when they found that small mutations altering the function of a protein called ETS1 can lead to an increased chance of inflammatory allergic reactions. This happens because the ETS1 protein controls a type of immune cell that coordinates and activates other immune cells, thereby moderating the immune response. In principle, altering the level of ETS1 could control allergic reactions.
According to data from the CDC’s National Center for Health Statistics, nearly one hundred million Americans show allergy symptoms, including seasonal allergies, food allergies, and eczema. With future advances in research and science, we may see the production of allergy vaccines in the next several years, which would significantly improve the lives of millions of people, and reduce the sniffles that we hear every spring in the hallways of IHS.