Acute stress, though sometimes tough to endure, might be good for the body and its ability to fight off disease.
Ohio State researcher Firdaus Dhabhar completed a decade worth of studies and research on the effects of acute stress and the body’s skin immunity. He presented his findings at the annual American Academy of Dermatology meeting in Washington, D.C. on Feb. 10.
Dhabhar, professor of oral biology and molecular virology, immunology and medical genetics, said, “We define acute stress as that which lasts for a few minutes to a few hours. An example of this would be working on an assignment to meet an upcoming deadline or rushing to get to class,” he said.
“Chronic stress is that which lasts almost continuously for weeks to months to years. An example of this would be enduring an abusive relationship or caring for a chronically ill child or spouse,” Dhabhar said.
Dhabhar also is conducting parallel studies in humans and animals.
“One of my central goals is to apply the knowledge gained from these studies to increase the efficacy of vaccines in order to boost the body’s response when any vaccine is administered,” he said.
He hopes to translate his lab findings into clinically useful applications.
“We have evidence that stress has a similar effect in humans. For example, in a study I conducted at Cornell University, we found that women with a history of childhood abuse show more robust immune responses,” Dharbar said. “One of the factors that mediates this higher immune reactivity may be that these subjects also show a higher reactivity to acute stressors.”
Disadvantages of acute stress exposure include the effects on allergies. If a person has a skin allergy, exposure to acute stress can make them worse, said Ronald Glaser, director of the Institute for Behavioral Medicine Research.
In his studies, rats and mice were divided into two groups. One group received exposure to stress and an antigen. The other group served as the control group and was only be exposed to the antigen.
An antigen is any substance that the body’s immune system reacts to by producing cells and antibodies, Dhabhar said. After exposure, both groups had their skin treated by the chemical or protein antigen.
The antigens used in the study were dinitrofluorobezene and keyhole limpet hemocyanin – both are models for studying a variety of immune reactions, he said.
Exposure to stress in the study was done by keeping the mice in well-ventilated restrainers for at least 30 minutes and up to two hours without causing any pain or compression. The animals could move slightly, but they could not run or walk.
“This triggers the innate escape stress response that rodents have. Such a response is nature’s way of helping them escape from a collapsed burrow. The survival mechanisms of this response are what we study,” Dhabhar said.
The immune system response was measured by looking at the increases in swelling at the site of the antigen exposure using a delayed hypersensitivity skin test, said Margaret Altemus, professor of psychiatry at Cornell University.
“The skin is an easy way to measure,” she said.
The group exposed to the stress and the antigen had a stronger immune response – two to four times greater – than did the control group.
The two groups were re-exposed to the antigen several months later. The control group showed a normal immune system response when re-exposed, while the group that was previously exposed to the stress remained much stronger, Dhabhar said.
He said he does not agree with certain findings of Dhabhar’s research because of the increase in memory cells when the stress is applied.
“I just do not see an increase in something like this to be good for someone,” Glaser said.
