The Ins And Outs Of Immunology
Research and Innovations Allergy suffererers are all too familiar with battling symptoms—runny noses, severe sniffles and watery eyes. However, there’s an alternative to carrying around a box of tissues.
How does immunotherapy affect the body’s reaction to the most common allergens such as grass, dust mite, cats and dogs and mold?
Allergens such as grass pollen etc. can cause an allergic reaction inside the nose causing inflammation of the tissues and resulting in sneezing, itching, runny nose and congestion. It can be associated with allergic conjunctivitis which is a similar allergic reaction in the eyes.
Allergic Rhinitis has a significant impact on patients’ social lives, as it may worsen their health-related quality of life, may impair their sleep, cognitive functions, work and school performance, may lead to significant economic costs for the affected patient and family.
The inflammation of Allergic Rhinoconjunctivitis can be part of a larger inflammatory process that affects the lungs, ears, and other organs .
In children it can cause learning problems and sleep-related disorders, such as obstructive sleep apnea syndrome, chronic and acute sinusitis, acute otitis media, serous otitis media, aggravation of adenoidal hypertrophy, and asthma.
"Allergic Rhinitis has a significant impact on patients’ social lives, as it may worsen their health-related quality of life, may impair their sleep, cognitive functions, work and school performance, may lead to significant economic costs for the affected patient and family."
Traditionally doctors provide their allergic patients treatments which consist of patient education, allergen avoidance (when possible) , pharmacotherapy for symptom relief and allergen-specific immunotherapy.
Commonly know as shots, allergen- specific immunotherapy consists of a solution containing one or more modified allergens, that the patient is allergic to, and is administered subcutaneously over many weeks.
The dose is increased incrementally and once it reaches a maintenance dose the frequency decreases to monthly injections. The duration and dose administered is crucial to achieve efficacy. This treatment results in reduction of symptoms and /or usage of medications; improvement in patient’s quality of life.
It is the only curative treatment of allergic rhinoconjunctivitis. Overall allergen immunotherapy induces tolerance to the offending allergen by multiple immunological mechanisms; including altering the body’s antibodies to the allergic inflammation, changing the responses of lymphocytes ( member of the white blood cell family) and dampening down the overall allergic inflammatory reaction.
What are the benefits of immunotherapy?
- Significant improvement in allergic symptoms and significant reduction in using over the counter antihistamines, eye drops and prescription drugs.
- In clinical research, studies with antihistamines are better than placebo by more than 12 percent.
- In clinical research trials, nasal steroids used as preventative treatment are better than placebo by 14-20 percent.
- Allergy immunotherapy improves symptoms by over 26 percent. It has powerful anti symptomatic effect starting as early as the first season after treatment onset, as shown in a recent study. Overall improvement was shown in quality of life: increased participation in outdoor activities, sports etc., as well as quality of sleep and less daytime fatigue. It can also result in marked improvement and in some patients change the natural course of the disease. In recent clinical trials, there is the potential of preventing the progression from allergic rhinitis to asthma. Some studies have shown that in allergy immunotherapy can reduce asthma symptoms and use of asthma medications.
How does it work?
There is up regulation of blocking antibody responses and down regulation of allergen specific IgE responses. IgE is the antibody that is responsible for the allergic reaction between the allergen( pollen/cat /yellow jacket) and the patient’s tissues.
T cells(class of lymphocytes) responses and reduction in the numbers and activation of proinflammatory cells (mast cells and eosinophils) are altered allowing the allergen to be to tolerated by the patient’s body. This results in decrease in the sensitivity of the patient’s end organs.
How do you know if immunotherapy is right for you?
The allergist should discuss the treatment options. If the offending allergen is an animal (e.g. cats) , simply removing it from your home can result in improvement. However, it is difficult to remove tree, grass and ragweed pollen / moulds.
The amount of treatment required, concomitant side effects and costs are all factors to be considered. Allergy immunotherapy is time consuming, takes place at a doctor’s office and can be inconvenient for many working patients. There are side effects to be considered, the most serious being a severe allergic reaction and for that reason it should be administered in a medical clinic.
What is the difference between seasonal and pre-seasonal allergies?
Allergic symptoms, in the eyes and upper respiratory system, can occur during the Spring, Summer or Fall depending on which allergen the patient is allergic to (e.g. ragweed). Allergy sufferers experience symptoms from mid August to the end of September.
Other allergens such as house dust mite can provoke symptoms in the late Fall and Winter. Many patients have allergic symptoms to one or more allergens. If the symptoms occur all year round then it is called perennial allergic rhinoconjunctivitis