Immunotherapy has been adopted as the best term to denote the slow immunizing process
of injecting allergenic extracts in ascending doses, which causes increased tolerance
to develop to the injected substance. It has come a long way since first used in
1911 by Noon, an English doctor. He administered crude grass pollen extracts to
patients with hay fever and noted reduction in their symptoms. Recent advances in
immunotherapy have depended on the improved understanding of IgE-mediated diseases,
the characterization of specific antigens and the standardization of allergen extracts.
Several randomized studies have shown that it is a very effective and safe treatment
for allergic rhinitis, allergic asthma and anaphylaxis to insect venom.
Immunotherapy has been reported by Timothy Sullivan, MD, from Emory University Atlanta,
to be "considerably less expensive than pharmacological treatment for asthma and
allergic rhinitis", based on a comparitive economic analysis.
The annual cost of pharmacotherapy for moderate to severe asthma was estimated at
$1,000 per year, and for allergic rhinitis, approximately $1,200. Allergen immunotherapy
is estimated at $800 for the initial year and $170 to $290 for each subsequent year
of maintenance therapy (depending on the number of antigens involved).
Summary Statements from the draft manuscript
A Practise Parameter
presented at the Allergen Immunotherapy Symposium at
the AAAA&I 58th Annual Meeting in New York March 1-6 2002
The joint Task Force on Practise Parameters, representing the American Academy of
Allergy, Asthma and Immunology, the American College of Allergy, Asthma and Immunology,
and the Joint Council of Allergy, Asthma and Immunology developed the parameters.
James T. Li , M/D.
Richard F. Lockey, M.D.
Jay M. Portnoy, M.D.
Leonard Bernstein, M.D.
Richard A. Nicklas, M.D.
Classification of Recommendations and Evidence
Draft Summary Statements
(Of the 69 draft summary statements available, only the statements considered of
interest to New Zealand doctors and patients are included below)
MECHANISMS OF IMMUNOTHERAPY
Immunologic changes during immunotherapy are complex. Successful immunotherapy is
associated with a shift from Th2 to Th1 CD4+ lymphocyte immune response to allergen.
Successful immunotherapy is also associated with immunologic tolerance, defined
as a relative decline in allergen specific responsiveness. (A)
Efficacy from immunotherapy is not dependent on reduction in Specific IgE levels.
Rises in allergen specific IgG blocking antibody titre are not predictive of the
duration and degree of efficacy of immunotherapy. (A)
Standardised extracts/vaccines should be used whenever possible
to prepare extract/vaccine treatment sets. (A)
Non-standardised extracts may vary widely in biologic activity. (B)
In choosing the components for a clinically relevant extract/vaccine, the physician
should be familiar with local and regional aerobiology with regards to both indoor
and outdoor allergens with special attention to potential allergens in the patients'
own environment. (D)
Knowledge of allergen cross-reactivity is extremely important in the selection of
allergens for immunotherapy because limiting the number of allergens in the treatment
vial is necessary to attain optimal therapeutic doses for the individual patient.