Scientists have few hard and fast answers to many of the questions raised by allergies. For instance: Why can one person eat a bag of peanuts to no ill effect, while another can die from merely breathing a little peanut dust? Why do people develop allergies at different ages? Or why can some people be allergic to raw apples, but okay with apple pie?
Visiting Assistant Professor of Chemistry Lesa Offermann admits, "There are lots of things we just don't know...yet!"
Offermann is part of a group of scientists around the globe who are trying to discern the answers to the questions that plague allergy sufferers and the medical profession.
As a structural biochemist, Offermann investigates the structural and functional relationships of several allergens–the substances that cause allergic reactions. She is conducting research with collaborators at the University of South Carolina, where she received her doctoral degree, at the U.S. Department of Agriculture, and overseas in Vienna, Italy and Poland.
Offermann noted that the current lack of structural information available on allergens drives her research. Her contribution to the effort involves purifying, crystallizing and determining the three-dimensional structures of allergens.
A depiction of some of Offermann's work appeared recently on the cover of the weekly publication Journal of Biochemistry. The background image of closely packed, spiky balls is ragweed pollen, while the red, white and blue ribbons represent the structure of the ragweed allergen, determined by the researchers to come from the pollen.
The cover illustration is associated with a paper inside the journal that Offermann authored about her successful work to determine the molecular structure of allergens from ragweed and mugwort.
Of the 13 different ragweed allergens known, Offermann said, only two ragweed allergens have their structures determined and deposited to the Protein Data Bank. The article presents the structures of another ragweed allergen, as well as the structure of a mugwort allergen.
The American Academy of Allergy, Asthma and Immunology reported last year that 20 percent of Americans suffer from allergies. Another study indicates that 15 million Americans and Canadians suffer from seasonal allergies, primarily from ragweed. Symptoms of allergic reactions, such as runny nose, swelling, rash or itching represent the immune system's defense mechanisms against allergens. Currently, there are no medications or vaccinations to prevent allergic reactions, though over-the-counter antihistamines can help alleviate symptoms.
While some allergens don't pose a serious health threat, others can cause life-threatening reactions in some people. The most common food allergens include "The Big-8"–milk, eggs, fish, shellfish, tree nuts, peanuts, wheat and soybeans. These eight account for approximately 90 percent of all food allergies in the United States. Because of their hazardous nature, any food containing the Big-8 are required by law to be properly labeled.
Many people who have severe reactions to certain foods carry EpiPens to inject themselves with medical grade epinephrine in case they face a serious allergic reaction.
Other common allergens are from pollen, dust mites, pet dander, insect bites and mold.
"The ultimate goal would be to figure out a way to prevent these allergic reactions from happening altogether," Offermann said. "But first you need to conduct basic research to find out what exactly is going on."
She and her colleagues have enjoyed some success.
"With different projects we've been able to determine which regions of the allergen interact with which regions of a specific antibody," Offermann said. "This gives us a clearer understanding of what's happening at the molecular level."
Offermann noted that of the approximately 800 allergens officially registered by the World Health Organization, only a small percentage have had their structures determined.
"That's where we come in," she said. "So far only about 100 allergens have their structures determined. So there's no lack of work for us to do."
Four Davidson students have been involved in Offermann's research; this fall one of them is investigating proteins from Sorghum bicolor, a grass grown for its grain.
So why is the number of people suffering from allergies on the rise? One increasingly accepted theory, the "hygiene hypothesis," contends that allergic reactions are caused by a lack of exposure to germs during childhood. Offermann agrees.
"We live in a much more sterile environment than in the past," she said.
Children should be exposed to microorganisms early on in order to promote proper immune system development, Offermann said, noting that some studies encourage introducing children to food allergens earlier than what was previously recommended by pediatricians.
"Any and all data we can collect, from basic research to clinical studies, will eventually allow us to answer the hard questions that aren't fully understood...yet," she said.