As reported in a One Health Initiative news letter, researchers, including veterinarians and doctors, are working to better understand diseases in animals and humans . A major study involves how Immune systems in horses and people react to certain triggers that cause airway inflammation and tightening of the associated muscles.
Making a heaves in horses, asthma in humans connection
Apparently some genetic factors, combined with exposure to environmental factors, result in human asthma and equine inflammatory airway disease and heaves, also called recurrent airway obstruction.
Since many of the triggers such as dust, debris from mites, weather are the same researchers hope to determine why the immune system reacts the way it does in some people and some horses.
Apparently some genetic factors, combined with exposure to certain environmental factors, result in human asthma and equine inflammatory airway disease and heaves, also called recurrent airway obstruction. Dr. Virginia Buechner-Maxwell is investigating what causes the diseases and how to prevent long-term damage from the diseases and the treatments. The goal is better treatments or cures.
"Horses are superb models for studying airway diseases because they develop these illnesses spontaneously, like humans,” explains Buechner-Maxwell, a professor of large animal internal medicine in the Virginia-Maryland Regional College of Veterinary Medicine at Virginia Tech. “They also are the only animals besides people that experience chronic changes of the disease as they age.”
Asthma and heaves often are the immune system’s response to an allergy, especially to airborne particles. “Allergies in general are a good example of what happens when the immune response is disproportionately intense relative
She is studying both the reasons for the inflammation of the airways and the changes associated with it, how the treatments affect the immune response, and the long-term disease/treatment ramifications.
Heaves in horses is much like asthma in adult humans, especially older people, because they may have worsen-worsening disease and long-term lung damage from the disease. Inflammatory airway disease in horses is more like pediatric asthma. In either case, horses and people can be treated the same ways — by keeping them away from the triggers as much as possible and taking some of the same drugs.
Horses have been fitted with surgical mask-type devices so that they can inhale the medication just like people. Inhaled corticosteroids to minimize inflammation and bronchodilators to open constricted airways are the standard medication now for long-term control of asthma to relieve inflammation.
One bronchodilator that is used is albuterol, a beta2–agonist that provides fast-acting relief of airway constriction and often is taken through an inhaler before participating in sports.
According to Buechner-Maxwell, new research in human medicine suggests that this medication also may influence the nature of the body’s inflammatory response associated with asthma .
She is studying the receptor that binds with beta2–agonists to determine whether-whethers these drugs affect inflammatory response in heavy horses as well. Specifically, she is investigating if albuterol affects the types of cytokines that immune cells produce after exposure to an allergen or irritant.
Cytokines are small proteins that signal cells to react in different ways. In the case of asthma or heaves, the cytokines produced by immune cells following allergen exposure differ from those that normal people and horses synthesize. Ultimately, these cytokines sig-signal events that result in airway inflammation experienced by affected horses and humans.
Horses age faster than humans, so immune re-response, drug effects, and long-term disease progression can be studied faster than in human patients.
The horse used as a model for asthma is also important because cell samples can be taken for testing of the immune response without harming the horse. In addition, horses age faster than humans so results of immune responses, drug effects, and long-term disease progression can be studied faster than in human patients.
This is an especially important factor when one of the research goals is to better understand chronic lung and bronchial tube changes that occur in people and animals with life-long airway disease.