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DATA SHOW COMMON ALLERGY TESTS ARE NOT INTERCHANGEABLE
-Results Vary
Widely Compared to Established Clinical Standards Using
ImmunoCAP-
PORTAGE, MI, May 8, 2008—Data published in
the May issue of the Journal of Allergy and Clinical Immunology revealed
variations in the results of three common allergy diagnostic
blood tests used to quantify sensitivities to allergens. The
study, conducted by allergy specialists at Mount Sinai School
of Medicine, determined that the laboratory results from
two other commercial tests for specific IgE were not equivalent
to those measured by ImmunoCAP® Specific IgE blood test.
Previously published studies from thought-leading allergists
have established threshold values for many food allergens. These
values are often used to guide decisions about the severity
of a patient’s food allergy and subsequent management
strategies. These published data are based upon values
determined using ImmunoCAP technology, which have become
well-established.
“Test results from the three different specific IgE
assays are not interchangeable. This study underscores
the importance of knowing which test is being used to generate
the patient’s results, particularly with food allergies,
which can be life-threatening,” said Robert Reinhardt,
MD, professor of family medicine for Michigan State University
College of Human Medicine and U.S. Medical Affairs Director,
Phadia US Inc.
Specific IgE is produced in the blood as a result of sensitization
to an allergen and typically increases with exposure to that
substance. High concentrations of food-specific IgE
levels are predictive of a food-induced allergic reaction. These
ImmunoCAP derived values provide a quantitative assessment
of allergen-specific IgE antibody, helping clinicians determine
the severity of an allergy and guide patient management strategies.
The assays used in this study included ImmunoCAP, Turbo-MP
(Agilent Technologies offered by LabCorp (Laboratory Corporation
of America)) and 3gAllergy Universal
Module (Siemens’ Immulite® system). The tests
measured specific IgE levels in 50
patients for egg, milk, peanut, cat, birch and dust mite.
The results revealed significant differences among the three
tests in the measurement of allergen-specific IgE levels,
which can impact the clinical decision-making process.
When quantitative evaluation was performed, the Turbo-MP
overestimated IgE levels for egg but underestimated levels
for dust mite and birch pollen. Differences also were
found between Turbo-MP and ImmunoCAP for milk, peanut and
cat. The 3gAllergy Universal Module overestimated all
allergen-specific IgE levels compared with ImmunoCAP.
“Results from these tests are used to guide treatment
decisions, and variability around the decision points can
alter clinical management of a suspected allergy,” concluded
the study authors. “Food allergen avoidance on
the basis of inconsistent laboratory results can have profound
nutritional and social implications and can significantly
affect a child and the child’s family’s quality
of life.”
Another study published in the Annals of Allergy, Asthma & Immunology in
July 2007 demonstrated that the ImmunoCAP Specific IgE system
was directly traceable to the World Health Organization (WHO)
standard preparation for total IgE in the detection of quantitative
specific IgE antibodies. This
traceability to the WHO standard was not equally demonstrated
with the Turbo-RAST and 3gAllergy Universal Module specific
IgE assays. The study was the first of its kind to
compare specific IgE results of different technologies as
measured against an independently verified IgE standard.
“These studies further validate ImmunoCAP’s
overall performance as compared to other specific IgE allergy
blood tests, making it a valuable option in the management
of allergic disorders,” said Michael Land, president
and general manager, Phadia US Inc. “Physicians and
patients need to be aware that not all allergy blood tests
are the same, and here is a study that concludes that interchanging
results can put children at unnecessary risk.”
Phadia AB, headquartered in Uppsala, Sweden, is the world
leader in in vitro IgE diagnostic research and product
development. Its U.S. affiliate is in Portage, Michigan. For
more information, call Phadia Customer Service at 1-800-346-4364.
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