Allergy, Asthma and Immunotherapy

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Allergy, Asthma and Immunotherapy
Give Your Patients Back Their Lives
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Facts Figures

• Over 60 million people in the US suffer from
  allergies
• If you have allergies, you may have undiagnosed
  asthma or be at risk for developing it
• Asthma is diagnosed in 7 of the population and
  is on the rise
• 80 of patients with asthma have allergic
  symptoms
• More than 20 of children with allergic symptoms
  develop asthma
• Allergy and asthma are more common in
  industrialized nations
• Asthma is the 6th most common primary care
  diagnosis

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How Does Allergy Work?

• The type of antibody responsible for allergy is
  IgE.
• IgE is thought to have evolved to recognize
  parasitic infections, such as intestinal worms.
• Bacterial infections are recognized by another
  antibody, IgG, which has a different,
  non-allergic, response.
• So, to an allergic immune system, a harmless
  protiean is the same thing as a parasitic
  infection.
• This is referred to as a Type I Allergy
  (IgE-Antibody-Dependent)
• There are other types of allergy (Type II, III,
  etc), but these have different mechanisms and are
  not relevant to our topic.

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Type I Allergy Sensitization (Complex View)

• Initial immune exposure
• Allergen encountered
• T cells activated (Th2)
• IgE produced towards allergen
• Mast cells bind circulating IgE
• Subsequent exposure
• Allergen binds IgE on mast cells
• Mast cells release chemicals that cause immune
  response
• Histamine
• Leukotrienes
• prostaglandins
• Organ-specific reaction (local)
• Peripheral reaction (systemic)

symptoms
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The Hygiene Hypothesis The cause?

• Based on global population studies, rates of
  allergy are much lower in poor countries that
  lack advanced sanitation and have more parasitic
  infections.
• When advanced sanitation is developed, these
  infections decline.
• However, the bodys ability to recognize and
  respond to these infections does not disappear.
  Instead, IgE simply reacts to other proteins the
  body is exposed to (pollen, cat hair, etc).
• This leads to a widespread pattern of unnecessary
  immune responses (allergy) in societies that have
  advanced sanitation.
• Therefore, rates of allergy and asthma are much
  higher in modern, wealthy societies.

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What is Asthma

• An inflammatory disease of the airways
• Triggered by many factors including allergens,
  environment, infections, and other irritants
• Most common symptoms
• Wheezing and dry cough
• Increased mucus production
• Bronchospasm and airway constriction
• Severity levels vary and can be measured by
  degree of decreased pulmonary function

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Diagnosing Asthma Severity

• Mild intermittent asthma Symptoms rarely occur
  and only after above normal levels of activity
• Mild persistent asthma Symptoms occur lt1/day and
  only exacerbated by activity
• Moderate persistent asthma Daily symptoms and
  routine activities become difficult. Oral
  corticosteroids needed.
• Severe persistent asthma Continual symptoms,
  must limit activity and many attacks occur.
  Additional daily treatments needed.

• Krouse, J, et al. OTO Head Neck Surgery
  2007136S75-S106

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Differential Diagnosis

• These conditions can be confused with asthma
  symptoms and should be considered during
  evaluation
• COPD
• Pulmonary fibrosis
• Tumors
• Infections
• GERD

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Between 1980 and 1998, reported cases of asthma
doubled in the U.S. The prevalence of asthma is
consistently higher in children.
CDC, Forecasted state-specific estimates of
self-reported asthma prevalence United States,
1998 MMWR 199847(47)1022-1025.
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The Cost of Asthma

• In 2007, the average annual medical cost for an
  asthmatic patient was 1,300 and continues to
  rise.
• While only 10-20 of patients have severe asthma,
  this accounts for over 50 of all asthma costs.
• Annual medical costs are 46 higher in patients
  with associated asthma and allergic rhinitis.
• In any given 12-month period there are
• 14 million lost school days
• 20 million missed work days
• 20 million outpatient visits
• 1.8 million ED visits
• 5,000 deaths

• Krouse, J, et al. OTO Head Neck Surgery
  2007136S75-S106

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Is Asthma Really Under Control?

• Relying on patient reports could overestimate the
  level of control.
• Patients often overestimate their pulmonary
  function when compared to peak flow results.
  This affects compliance with medication.
• Symptom management often misses underlying issues
  like allergies.
• Be Proactive. Dont wait for symptoms to present
  themselves.

• Krouse, J, et al. OTO Head Neck Surgery
  2007136S75-S106

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Linking Allergies with Asthma

• Allergy is one of the main triggers of asthma and
  is often a precursor.
• There is a significant correlation between the
  severity of allergic rhinitis and the ability to
  control asthma.
• Exposure to allergens can cause rapid onset of
  bronchospasm.
• Doctors frequently overlook the allergic trigger
  in asthmatic patients or the asthmatic potential
  in allergic patients.

• Vinuya, R. Ann Allergy Asthma Immunol
  200288(Suppl)8-15
• Krouse, J, et al. OTO Head Neck Surgery
  2007136S75-S106

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The Unified Airway - Linking Allergies and Asthma
Isolated irritants in one part of the respiratory
system have been shown to cause inflammation in
distant parts, suggesting a common inflammatory
pathway.
Inflammation in the upper respiratory tract
Inflammation in the lower respiratory tract

• Vinuya, R. Ann Allergy Asthma Immunol
  200288(Suppl)8-15
• Ricca, V, et al. J Allergy Clin Immunol
  199910454-57
• Serrano, C, et al. Arch Bronconeumol
  200541(10)569-578

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Allergens Causing Asthma?

• Chronic allergens can drastically increase the
  risk of developing asthma in vulnerable patients
• Dust Mites
• Molds
• Pets (Hair Dander)
• Cockroaches
• Allergic responses to these allergens can also be
  interpreted as uncontrolled asthma, which masks
  the underlying cause and delays adequate
  treatment.

Vinuya, R. Ann Allergy Asthma Immunol
200288(Suppl)8-15 Gaffin, J, Phipatanakul, W.
Curr Opin Allergy Clin Immunol 20099(2)128-135
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Important Tests for Potential Immunotherapy
Patients

• Allergy
• The patients allergic response must be diagnosed
  as Type I hypersensitivity (IgE antibody
  mediated) through skin or in-vitro testing.
• Skin test results can be used as an immediate
  educational tool to illustrate the impact of
  different allergens to the patient.
• Respiratory
• An objective evaluation of patient lung function
  establishes a baseline for monitoring disease
  progression
• Commonly done with Peak Flow and Spirometry
• Requires patient and staff training to implement
  effectively

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Controlling the Allergy Trigger

• Avoidance
• Can be effective if used in combination with
  treatment
• However, many allergens are essentially
  unavoidable
• Symptomatic treatment (e.g. Antihistamines)
• Provides immediate relief
• However, doesnt change the underlying cause of
  the symptoms.
• Relief only lasts as long as the patient is
  compliant.
• Immunotherapy
• Changes the underlying immune response to the
  allergen
• Provides long-term relief
• May see a positive impact within 3-6 months

Serrano, C, et al. Arch Bronconeumol
200541(10)569-578
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Immunotherapy and Asthma

• Allergy Immunotherapy (IT) has been shown to
• Reduce allergic rhinitis thus improving asthmatic
  symptoms
• Reduce the need for asthma medications
• Reduce general inflammation in the airways over
  time
• Drastically slow or halt the progression of
  asthmatic disease
• In numerous clinical studies, subjects reported
  significantly fewer asthma symptoms and required
  less asthma medication than the placebo group.
• Experts found that IT was effective in treating
  allergic asthma in 71 of patients.

Passalacqua, G, Durham, S. J Allergy Clin
Immunol 2007119881-891 Abramson, M, et al.
Allergy 1999541022-1041 Ross, R, et al. Clin
Ther 200022329-341 Jacobsen, L, et al. Allergy
200762943-948
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Immunotherapy is the only treatment that
influences the basic course of allergic disease
World Health Organization (WHO) Position Paper,
1998
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Recommendations of the Allergic Rhinitis and Its
Impact on Asthma (ARIA) Workshop Group

• Patients with persistent rhinitis should be
  assessed for the presence of asthma.
• Patients with persistent asthma should be
  assessed for the presence of rhinitis.
• An appropriate therapeutic strategy should
  combine safe and effective management of the
  upper and lower airways.

Adapted from Serrano, C, et al. Arch
Bronconeumol 200541(10)569-578 .
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Refer to An Allergist

• National Asthma Education and Prevention Program
  guidelines recommend that patients who require
  daily asthma medication be considered for allergy
  testing.
• If a patients allergies can not be controlled,
  and they are a candidate for immunotherapy, they
  should be referred to an Allergist.

Platts-Mills, T, et al. Am Fam Physician
200776675-680 .
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Asthma Candidates for Immunotherapy

• The patients allergic response is a major
  component of his/her asthma symptoms
• There is clear evidence that the patient is
  exposed to, and symptomatic towards, unavoidable
  allergens
• Symptoms are chronic and persistent
• Patient requires daily asthma medications
• Patient is interested in treatment options
  besides medication

Platts-Mills, T, et al. Am Fam Physician
200776675-680 .
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Immunotherapy Precautions

• IT does not provide immediate improvement
• IT can be dangerous, resulting in anaphylaxis in
  some patients
• Patients with uncontrolled asthma should NOT be
  given IT since they are more likely to have
  severe adverse reactions

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Summary

• Asthma is a complex disease, influenced by many
  factors
• Since asthma shares a common inflammatory pathway
  as allergic rhinitis, with significant
  comorbidity, both conditions should be addressed
  simultaneously.
• In some asthma patients, immunotherapy may be an
  effective treatment option.