Do cat allergies keep you from having the pet you would love to have? Or do your allergies force you to cut short visits with friends who have felines? Researchers at McMaster University are hopeful that your itching eyes and running nose may soon be a thing of the past thanks to their new vaccine to treat people with cat allergies.
Having an allergy means your immune system reacts to particles that are known as the allergen. In the case of cats, these particles are usually dead skin cells called dander or dried saliva that gets on the cat’s hair when it grooms itself. When you come in contact with a potential allergen that you are not allergic to, your immune system ignores it. But if you are allergic, your immune system jumps into action to fight off what it believes is an invasion of harmful particles.
When the immune system senses an allergen, a protein in the allergen triggers the body to make antibodies that are targeted against the allergen. These antibodies cause the symptoms we normally associate with allergies including runny nose, itchy and watery eyes, and swelling around the nose and mouth. Touching the allergen can also cause hives or itchy patches on the skin. Cat allergy symptoms often include coughing, wheezing, and shortness of breath. These symptoms can come on as quickly as within 15 to 30 minutes of encountering the allergen. Cat allergies can trigger a severe asthma attack in up to 30 percent of people who have asthma. People with severe cat allergy can also experience a potentially deadly reaction called anaphylaxis which can cause them to stop breathing.
Standard treatment for cat allergies varies based on how severe the allergy is. Some people can get by with taking antihistamine medications. Others find that frequent allergy shots offer the best relief. And many chose to get rid of their cat and try to avoid places where cat dander may be present, even if it means skipping a family visit to a home with cats.
That’s where the work of immunologist Mark Larché comes in. Larché is a professor in the Department of Medicine at the Micheal G. DeGroote School of Medicine and is the Canada Research Chair in Allergy & Immune Tolerance. Over the past 10 years, Larché and his team have worked to create a vaccine against cat allergies that testing shows to be safe and effective with almost no side effects. Their research was published in the January 2011 issue of the Journal of Allergy & Clinical Immunology.
Researchers narrowed their study to a specific protein in cat saliva that causes most allergy symptoms. By breaking down the protein into individual amino acids, they were able to determine which parts of the protein trigger the response from the immune system. This allowed them to create a vaccine known as “peptide immunotherapy” that can keep the immune system from being activated when the real protein is present.
The vaccine is injected into the skin, much like existing allergy shots. But rather than weekly shots, researchers plan to start patients on the new vaccine with four to eight small doses a year. Phase three clinical trials will help isolate the ideal dosage as more allergy sufferers are involved in the testing.
Once the cat vaccine is complete and approved, the team has plans to develop similar peptide immunotherapy treatments for people who are allergic to ragweed, dust mites, grass, birch trees, and molds.
Sources:
Science Daily
Asthma and Allergy Foundation of America
American College of Allergy, Asthma & Immunology
Mayo Clinic