Antigen leukocyte cellular antibody test

The antigen leukocyte cellular antibody test (ALCAT) is a procedure created by American Medical Testing Laboratories and now marketed by Cell Science Systems, of Deerfield Beach, Florida, also known as ALCAT Diagnostic Systems. They marketed the procedure as an in-vitro screening test for adverse reactions to specific foods, food additives, food colourings and other chemicals, between 1984 and 1986. Since this time the original test method has been modified.

Journal articles, reviews, and allergology associations' position papers have characterized the ALCAT as an "unproven method" for diagnosing allergies, advised against its use, and concluded that relying upon the results of this test may lead to inappropriate advice and treatments.[1][2][3][4] A review by Gerez et al writes that it

is an inappropriate modality for testing food allergy in clinical practice mainly because of its poor reproducibility, as well as its a lack of scientific and clinical proof of efficacy. It is therefore not recommended to be used for diagnosing allergies of any form.[4]

Contents

Food intolerance

Main article: Food intolerance

Food intolerance is the reaction to chemical components of the diet and is more common than true food allergies. It is caused by various organic chemicals occurring naturally in a wide variety of foods, both of animal and vegetable origin, in addition to food additives, preservatives, colourings and flavourings, such as sulfites or dyes. Both natural and artificial ingredients may cause adverse reactions in sensitive people if consumed in sufficient amounts, the degree of sensitivity varying between individuals.[5][6]

Researchers from Dubai published an uncontrolled, unblinded primary study asserting the effectiveness of custom diets based on individual ALCAT "food sensitivity" test results for weight loss.[7]

Test

As described by the vendor, the ALCAT test is performed using a modified Coulter counter, which counts and sizes white blood cells before and after incubation with specially prepared proprietary gels. These gels represent the different food items that can be tested for. The resultant data is then analyzed by a computer which compares each mixture of gel and reacted blood with an unreacted control (the patient's unreacted blood). A testing machine which the vendor brands as ROBOCAT II, prints a histogram of one superimposed on the other. This data then is converted to a test result, which is said to categorize each item tested and show this in the form of a color coded chart.[8]

Effectiveness

Official position statements assessing the test as unproven and opposing the clinical use of the test have been issued by the Allergy Society of South Africa[9][10][11] Australasian Society of Clinical Immunology and Allergy,[12] European Academy of Allergology and Clinical Immunology,[13] and the American Academy of Allergy.[14] Several studies have shown that the ALCAT test lacks clinical efficacy and should not be used to guide therapeutic decisions.[15][16][17]

References

  1. ^ Wüthrich B (2005). "Unproven techniques in allergy diagnosis" (pdf). J Investig Allergol Clin Immunol 15 (2): 86–90. PMID 16047707. http://www.jiaci.org/issues/vol15issue02/1.pdf. 
  2. ^ Beyer K, Teuber SS (June 2005). "Food allergy diagnostics: scientific and unproven procedures". Curr Opin Allergy Clin Immunol 5 (3): 261–6. doi:10.1097/01.all.0000168792.27948.f9. ISSN 1528-4050. PMID 15864086. 
  3. ^ Potter PC, Mullineux J, Weinberg EG, et al. (April 1992). "The ALCAT test--inappropriate in testing for food allergy in clinical practice". S Afr Med J 81 (7): 384. PMID 1561573. 
  4. ^ a b Gerez IF, Shek LP, Chng HH, Lee BW (2010 Jan). "Diagnostic tests for food allergy". Singapore Med J 51 (1): 4-9. PMID 20200768. 
  5. ^ Lifschitz C (November 2008). "Is there a consensus in food allergy management?". J. Pediatr. Gastroenterol. Nutr. 47 Suppl 2: S58–9. doi:10.1097/01.mpg.0000338816.82556.40. PMID 18931604. 
  6. ^ Spergel JM, Brown-Whitehorn TF, Beausoleil JL, et al. (January 2009). "14 years of eosinophilic esophagitis: clinical features and prognosis". J. Pediatr. Gastroenterol. Nutr. 48 (1): 30–6. doi:10.1097/MPG.0b013e3181788282. PMID 19172120. 
  7. ^ Mohammed Akmal, Saeed Ahmed Khan, Abdul Qayyum Khan (April 2009). "The effect of the ALCAT test diet therapy for food sensitivity in patient’s with obesity". The Middle Eastern Journal of Family Medicine 7 (3). ISSN 1448-4196. http://www.mejfm.com/mejfmApr09_vol7-iss3/alcat.htm. 
  8. ^ Neetling, WML; Kachelhoffer AM (1998). "Reproducibility of the antigen leucocyte cellular antibody test (ALCAT)" (pdf). ALCAT.com (corporate site). pp. 1–4. http://www.alcat.com/assets/File/REPRODUCIBILITY%20OF%20THE%20ANTIGEN%20LEUCOCYTE%20CELLULAR%20ANTIBODY%20TEST.pdf. Retrieved 2009-02-13. 
  9. ^ Potter PC, Mullineux J, Weinberg EG, Haus M, Ireland P, Buys C, Motala C (4 April 1992). "The ALCAT test--inappropriate in testing for food allergy in clinical practice". S Afr Med J 81 (7): 384. PMID 1561573. 
  10. ^ Allergy Society of South Africa (2007). "ALCAT and IgG allergy and intolerance tests.". S Afr Med J (Allergy Society of South Africa) 98 (3): 167. PMID 18350212. http://www.samj.org.za/index.php/samj/article/viewFile/877/823. "Consensus statements released by allergy societies throughout the world as well as the World Allergy Organization do not recommend the use of this test in the evaluation of acute or delayed allergic or intolerance reactions. Significantly, not a single non-allergy clinical society worldwide has supported the use of the ALCAT. These viewpoints have been reiterated in recent international reviews of allergy diagnostic tests. It is significant that there are also no peer-reviewed publications or any reasonable studies to support a diagnostic value for the ALCAT" 
  11. ^ "Allergy Society of South Africa position statement on ALCAT and IgG Allergy & Intolerance Tests" (pdf). http://www.allergysa.org/pdfs/intolerance_tests.pdf. Retrieved 2009-03-11. 
  12. ^ Mullins Raymond J (on behalf of the Education Committee) (November 2007). ASCIA position statement: unorthodox techniques for the diagnosis and treatment of allergy, asthma and immune disorders. Australasian Society of Clinical Immunology and Allergy. http://www.allergy.org.au/content/view/322/271/. "These results have been shown to not be reproducible, give different results when duplicate samples are analysed blindly, don't correlate with those from conventional testing, and 'diagnose' food hypersensitivity in subjects with conditions where food allergy is not considered to play a pathogenic role." 
  13. ^ Ortolani C et al. (1999). "Controversial aspects of adverse reactions to food". Allergy 54 (1): 27–54. doi:10.1034/j.1398-9995.1999.00913.x. PMID 10195356. http://www.eaaci.net/site/Adverse%20reactions%20to%20food.pdf. 
  14. ^ [No author listed] (1981). "American Academy of Allergy: position statements--controversial techniques". J Allergy Clin Immunol 67 (5): 333–8. doi:10.1016/0091-6749(81)90076-2. PMID 7014691. 
  15. ^ Wüthrich B (2005). "Unproven techniques in allergy diagnosis". J Investig Allergol Clin Immunol 15 (2): 86–90. PMID 16047707. 
  16. ^ Benson TE, Arkins JA (October 1976). "Cytotoxic testing for food allergy: evaluation of reproducibility and correlation". J Allergy Clin Immunol 58 (4): 471–6. doi:10.1016/0091-6749(76)90190-1. PMID 787048. 
  17. ^ Mullins Raymond J, Heddle Robert J, Smith Pete (2005). "Non-conventional approaches to allergy testing: reconciling patient autonomy with medical practitioners’ concerns". Med J Aust 183 (4): 173–4. PMID 16097911. http://www.mja.com.au/public/issues/183_04_150805/mul10358_fm.html. "This test continues to be used today, despite evidence that results are not reproducible, are different when duplicate samples are analysed blindly, do not correlate with those from conventional testing, and “diagnose” food hypersensitivity in people with conditions in which food allergy is not considered to play a pathogenic role." 

Additional reading

External links