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Growth in Allergy Testing

Advances in allergy diagnostics mean faster, more accurate results.

By Jason A. Kendall, BS, BA, MT (AMT), Safedin “Sajo” H. Beqaj, PhD, HCLC, CC (ABB) and Kathy Braniff, MT (ASCP)

Allergy reactions range from runny nose, watery eyes, coughing and congestion to asthmatic reaction that can last for several days are not just miserable, but can negatively impact our quality of life and cause decreased work and school productivity. In addition, if allergies are misdiagnosed or go untreated, there is higher probability that the patient will develop additional, more severe symptoms, including asthma. The progression from allergy to asthma is becoming a widespread health problem. The financial impact associated with allergies and allergic diseases is significant. Billions of dollars are spent annually on allergies: $4.5 billion on direct care and $3.4 billion on indirect costs related to lost work productivity.1Unfortunately, allergies are still not recognized as a medical problem; most are considered symptoms or syndromes, not diseases.On the Rise

Allergies and allergen-related disease statistics show an alarming trend over past decades. Allergic disease is the fifth leading chronic disease in the U.S. and third among children under 18 years of age. Asthma rates in children under the age of five have increased more than 160% from 1980 to 1994. Global warming, pollution from the burning of fossil fuels, use of sanitizing agents and antibiotics are factors that could be impacting the higher rates. Heredity also plays an important part. If one parent has allergies, the probability of having a child with allergic tendencies is 30-40%. If both parents have allergies, the probability grows to 70-80%. The medical community, including clinical testing labs, has to rise to the occasion to meet the demand associated with this trend.

The World Allergen Organization (WAO) acknowledges a lack of pathology training within the physician community in allergens and allergy disease treatment. The group says most allergy sufferers are treated by primary care physicians instead of trained specialists, and points to two reasons: Medical schools have lagged in scientific/clinical developments for the relatively new specialty, and undergraduate programs lack appropriate education and training requirements.2 The American College of Allergy, Asthma and Immunology predicts a need for 35% more allergists by 2020. The Allergy America Program is actively working to give primary care physicians the education, training and support to meet an expected shortfall.

Diagnosis

Allergy diagnosis can be enhanced by a strong history and physical exam with differential testing to determine patient specific allergen response. Historically, this could be performed by “scratch testing” in the physician office where the patient was scratched with a needle containing specific allergen extracts and observed for a skin reaction. Allergic response was measured to determine positive and negative reactions to the extract. Scratch or percutaneous testing has become more refined. New techniques and products allow safe administration of up to 60 allergens in less than a minute with reaction results available in 15 minutes.

The 1966 discovery that antibodies of the IgE class are responsible for allergic disease has opened the door for clinical labs to provide testing for diagnosis and treatment of allergic disease. Lab systems developed to support IgE testing have become standardized. IgE antibodies are sensitive and specific, minimizing cross reactivity, and calibrated to an international standard. Advantages include that the testing:

  • is not affected by medications,
  • eliminates anaphylaxis reaction risk,
  • is not limited to certain patient populations (e.g., pediatric, obstetric, etc.) and
  • is quantitative and reproducible.

Testing Improvements

Until recently, point-of-care lab equipment for allergen testing was unheard of. Now a capillary sample can be taken from the patient and tested for several IgE inhalants. IgE reactivity is measured relative to specific allergens as a serum-based test. Usually this method can replace the more frequently used skin testing method and provide the physician with a quantitative level of the allergen.3

Advancements in technology and instrumentation software are rapidly ending the esoteric mindset for allergen testing in the clinical lab. Automation and broader platforms are the noted influence for this.4 Total IgE and allergen-specific IgE testing of the past were expensive and had lower sensitivity and specificity. Highly automated, newer colorimetric or fluorometric methodologies improve reproducibility5 and test for a variety of allergens. Special allergen panels tailor to the needs of patients/physicians and can be adapted by almost any size lab. Reimbursement for allergy testing has not historically been great; however, allergen test panels provide a cost-effective way to bring in revenue.

The clinical lab role in diagnosis of allergies is evolving–moving from extract-based to component-based analysis and from singleplex to multiplex platforms. While allergy statistics point to record highs, much is being done within the medical community to rise to the occasion.

Jason A. Kendall is a consultant at Clinical Lab Consulting LLC, Carmel, IN, and Safedin “Sajo” H. Beqaj is technical laboratory director, and Kathy Braniff is senior laboratory manager, both at DCL Medical Laboratories, Indianapolis. 

References

1. CDC: Fast Stats A-Z. Vital and Health Statistics, Series 10, no. 200. Table 57. 1996.

2. Recommendations for Competency in Allergy Training for Undergraduates Qualifying as Medical Practitioners: A Position Paper of the World Allergy Organization. World Allergy Organization Journal, 2009;2;8;150-4. Available at:

3. Rose S. Allergies Are Nothing to Sneeze At. Clinical Lab Products. 2010. Available at:
www.clpmag.com/issues/articles/2010-03_03.asp. Accessed April 25, 2010.
http://journals.lww.com/waojournal/Fulltext/2009/08000/Recommendations_for_
Competency_in_Allergy_Training.1.aspx.
Accessed April 25, 2010.

4. Titus K. Lab-based allergy testing on the march. CAP Today. 2002. Available at: www.cap.org/apps/cap.portal?_
nfpb=true&cntvwrPtlt_actionOverride=%2Fportlets%2FcontentViewer%2Fshow&_window
Label=cntvwrPtlt&cntvwrPtlt%7
BactionForm.contentReference%7D=cap_today%2Fcover_stories%2Fallergy_cover.html&_state=
maximized&_pageLabel=cntvwr.
Accessed April 25, 2010.

5. Zarbock S. A simple new blood test for allergy triggers. 2009. Available at:
JAAPA www.jaapa.com/a-simple-new-blood-test-for-allergy-triggers/article/138560/#. Accessed April 25, 2010.

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