Update on Laboratory Testing to Identify Individuals With Inhalant Allergies Anna Wetherbee (President, HW Consulting)
Originally published in LABMEDICINE (Lab Med. 2007;38;649–650).
The quality and cost of health care in the United States is
and enzymeimmunoassay (EIA) tests that use color development,
increasingly a focus of media and political debate. Breakthroughs
fluorescence, or chemiluminescence for detection of allergen-
in medical technology and the discovery of new treatment op-
specific IgE antibody, advances in technology have increased the
tions for a variety of diseases, alongside serious concerns about
reliability and diagnostic sensitivity of these tests in identifying
increasing health care costs and the rising number of uninsured
individuals with IgE-mediated disease. These advances have
Americans, make frequent headlines. In the midst of discoveries
caused many experts to conclude that blood tests are as useful as
and debates that are shaping the future of American health care,
skin testing for helping clinicians determine the presence or
an unlikely topic has been getting a surprising amount of atten-
absence of allergy and specific allergen sensitivities.8
tion: allergy testing. Although the newest diagnostic technologies
In vitro diagnostic technology promises at least 1 significant
related to the identification and treatment of individuals with
benefit: PCPs now have an objective tool to differentiate
inhalant allergies are more than a decade old and hardly break-
between allergic and non-allergic disease and implement more
ing news, allergy testing has been highlighted in recent articles
effective treatment strategies in their patients. In 1999 and 2000,
in both The New York Times1 and The Wall Street Journal,2 as
the leading manufacturer of blood allergy testing, Phadia (for-
well as in several industry publications.
merly Pharmacia Diagnostics), initiated a marketing campaign
So why all the attention being given to allergy testing?
to bring this tool to the primary care setting. Using the promo-
The simple answer may be that while the technology related to
tional slogan “Is It Allergy?” Phadia proposed that the use of a
allergy testing is not new, the paradigm for using it is. Allergy
panel of individual tests for common allergens could provide
testing, once the exclusive domain of specialists, has been more
value in the discrimination of individuals with inhalant allergy
recently marketed to primary care physicians (PCPs), sparking
disease from those without this disease.
an intense debate over what constitutes clinically-appropriate
An accurate differential diagnosis of allergic versus non-
allergic disease has significant potential benefits. It can direct
Consider this: more than 50% of Americans identify them-
physicians to more appropriate care, improving patient
selves as seasonal allergy sufferers.3 Clinical evidence suggests that
outcomes and satisfaction. It may also decrease costs from re-
among these individuals, more than half in fact do not have an
peated office visits due to ineffective treatment. Diverting non-
inhalant allergy.4-6 Moreover, the majority of these individuals are
allergic patients from high-cost allergy drugs to more
treated by PCPs and rarely see an allergy specialist, which means
cost-effective and clinically-appropriate options can save signifi-
few of them ever receive objective diagnostic testing to confirm
cant pharmacy costs for insurers. Finally, it may improve referral
whether their symptoms are truly caused by an inhalant allergen
patterns, providing a simple solution for primary care while bet-
or not. The result is a large number of patients being presump-
ter identifying patients for specialist referral who may need more
tively diagnosed and treated for allergies, many of whom do not
extensive allergy testing and treatment.
in fact have an allergy-mediated disease.7 This can be costly for
Allergy testing in the primary care setting soon became big
patients, physicians, and insurance companies who share the
business. Two years into Phadia’s primary care marketing cam-
burden of ineffective treatment and inadequate outcomes.
paign, Quest Diagnostics partnered with Phadia to promote
Manufacturers of blood tests for specific allergens aim to
their message through its sizeable direct-to-physician sales force.
change that. Traditionally, allergy testing has been performed
According to Surya Mohapatra, President of Quest Diagnostics,
by a trained specialist using skin-prick testing with specific allergens.
in April 2006, “…allergy testing has grown steadily and signifi-
Blood tests, or allergen-specific IgE antibody in vitro diagnostic
cantly. Our efforts have focused on educating primary care
tests, which quantitatively measure the presence or absence of
physicians and pediatricians about the benefits of allergy blood
allergen-related IgE antibodies in serum prepared from an indi-
testing. Instead of referring patients to specialists, the primary
vidual’s blood sample, can be ordered by PCPs or specialists.
care physicians now are able to test their patients and prescribe
In vitro diagnostic tests for allergen-related antibodies have
improved significantly since their creation in the early 1970s. From
Despite the clinical appeal of a simple, objective laboratory
the first radioallergosorbent test (RAST) to the more sensitive mod-
test to enable better identification of individuals with allergic
ified RAST, to the current automated radioimmunoassay (RIA)
disease in the primary care setting, PCPs have been slow to
November 2007 Volume 38 Number 11 LABMEDICINE 649
embrace in vitro allergy testing in the routine management of
be positive. However, the added value of specific allergen infor-
their patients. This hesitance may be due in part to a question-
mation in guiding treatment in primary care is controversial.
able total value proposition. Currently, the most common in
Using the MIA test as a first-line strategy in the evaluation of
vitro allergy testing approach uses a panel of 15 or more com-
patients with suspected allergic disease may limit more exten-
mon specific allergens to identify individuals with allergic dis-
sive testing, and its attending cost, to only those patients with
ease and the most likely allergen triggers causing their disease.
bona fide IgE-mediated hypersensitivity disease.
Billing for these panels is computed on a per allergen basis and
There is an urgent need in health care today to improve
may cost as much as $185 (based on the current Medicare fee
patient outcomes while managing costs. The laboratory testing
schedule), offsetting potential savings. A recent pilot study at
options and strategies for achieving these goals in the manage-
Wilford Hall Medical Center, San Antonio, TX, found that
ment of allergic disease in primary care have been reviewed
the direct cost of testing symptomatic patients with a panel of
briefly above. Laboratory professionals can play a key role in
specific allergens outweighed the direct estimated savings from
educating physicians about available laboratory test options and
eliminating inappropriate prescriptions.10 Additionally, while
promoting implementation of clinically-effective and cost-effi-
accurately discriminating between allergic and non-allergic
cient laboratory testing strategies in the management of allergy
patients provides clear clinical value, some experts question
and other diseases. LM
the value of identifying specific inhalant allergen sensitivities,
Disclaimer: HW Consulting has no conflicts of interest or
especially pollens, in primary care patients, given the expense
disclosures. HW Consulting provides consulting services in the
and practical limitations of avoiding allergen exposure as a
areas of reimbursement, health care economics, and disease man-
symptom management strategy. According to Dr. Henry
agement, and has had prior consulting relationships with 2 of
Homburger, Professor of Laboratory Medicine at the Mayo
the leading allergy diagnostic manufacturers. For more informa-
Clinic, “the most common misuse of tests for individual IgE
tion regarding HW Consulting, see www.hw-consult.net.
antibodies occurs when tests are ordered in large numbers to‘look for allergy’ or screen in a patient who does not have clini-
1. Tarkan L. In testing for allergies, a single shot may suffice. The New York
cal signs and symptoms or a medical history that strongly sug-
gests immediate hypersensitivity disease.”11
2. Fuhrmans V. Doctors assail UnitedHealth’s threat of fines. The Wall Street
A multiple inhalant allergen (MIA) test, otherwise known
as a “multiallergen test” (CPT 86005), usually consisting of a
3. ICR. Survey reveals allergies show no boundaries, no matter where you live.
combination of 6 to 12 allergens in a single test, may be a more
Available at: http://www.icrsurvey.com/Study.aspx?f=zyrtec.html.
cost-effective and clinically-useful alternative to a panel of spe-
4. Szeinbach SC, Williams PB. Identification of allergic disease among users of
cific allergen tests in identifying individuals with inhalant al-
antihistamines. JMCP. 2004;10:3.
lergy disease in primary care. The MIA test has a diagnostic
5. Altman CL, Becker JW, Williams PV. Allergy in Primary Care. Philadelphia:
efficiency that compares well with that of skin testing and anegative predictive value for allergic rhinitis of >95%.12 In fact,
6. Dykewicz MS, Fineman S, Skoner DP, et al. Diagnosis and management of
rhinitis: Complete guidelines of the Joint Task Force on Practice Parameters
the multiallergen test has the highest negative predictive value
in Allergy, Asthma, and Immunology. Ann Allergy Asthma Immunol. 1998;81:
for atopic dissease of any laboratory test currently available.13
Moreover, Poon and colleagues14 commented, “qualitative mul-
7. Szeinbach S, Brock W, Muntendam P, et al. Identification of allergic disease
tiallergen screening tests have been found to be clinically effec-
among users of antihistamine. J Manag Care Pharm. 2004;10:234–238.
tive, having excellent sensitivity, specificity, and efficiency,” and,
8. US Department of Health and Human Services, National Institutes of Health.
Expert panel report 3: Guidelines for the diagnosis and management of
“the AAOA [American Academy of Otolaryngic Allergy] deter-
asthma. NIH Publication No. 07-4051:167. Bethesda, MD: NIH; 2007.
mined that it is possible to decrease the number of tests without
9. Quest Diagnostics, Quarter ended March 31, 2006. Conference call prepared
compromising clinical practice by: 1) using screen to remove
non-allergic patients from further unnecessary testing; and 2)
10. Welsh N, Hart J, Hoeben B, et al. The pharmacoeconomic impact of
eliminating cross-reactive or unusual allergens from a typical
ImmunoCAP testing on the usage of second-generation antihistamines and a
allergen panel unless indicated by clinical history.” In addition,
leukotriene receptor antagonist at Wilford Hall Medical Center. J Am PharmAssoc. 2006;46:627.
HA Sampson, a prominent pediatric allergist, has stated, “as
11. Homburger HA. Mayo Reference Services “Communique.” September, 2004.
suggested by us many years ago, and as convincingly shownmore recently by Fiocchi et al, qualitative multiallergen tests
12. Linneberg A, Husemoen LLN, Nielsen NH. Screening for allergic respiratory
disease in the general population with the ADVIA Centaur allergy screen assay.
provide an excellent means for primary care physicians to iden-
tify atopic children, enabling them to provide more appropriate
13. Leung DM, Sampson HA, Geha RS, et al. Pediatric Allergy, Principles and
care for patients with mild disease or to refer those with more
Practices. Philadelphia: Mosby; 2003: 238.
severe disease for further allergy evaluation.”15
14. Poon AW, Goodman CS, Rubin RJ. In vitro and skin testing for allergy:
Unlike testing for specific allergens, the MIA test, if posi-
Comparable clinical utility and costs. Am J Manag Care. 1998;4:969–985.
tive, will not identify the specific allergen causing this test to
15. Sampson HA. Guest Editorial: “Can we diagnose atopy with a laboratory
test?” Ann Allergy Asthma Immunol. 2004:93;307–308. LABMEDICINE Volume 38 Number 11 November 2007
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