Archive for October, 2009

IgG antibody tests don’t indicate food intolerances.

Thursday, October 29th, 2009

In the UK, blood tests for immunoglobulin G4 (IgG4) against foods are actively promoted for the diagnosis of food intolerance and hypersensitivity. Mounting clinical research indicates that food-specific IgG4 allergy testing does not indicate (imminent) food allergy or intolerance, but is rather a normal physiological response by the immune system after food exposure. In fact IgG4 is more likely to indicate food tolerance and that the person can safely eat that food with no adverse effect. This should not be confused with IgE which is the main allergy antibody used in allergy testing and this has an established “track record” in conventional allergy diagnosis.

Not really convinced? Have a look at these research papers:

No recommendation for IgG and IgG4 testing against foods  
J. Kleine-Tebbe, I. Reese, B. K. Ballmer-Weber, K. Beyer, S. Erdmann, Th. Fuchs, M. Henzgen, A. Heratizadeh, I. Hutt egger, L. Jäger, U. Jappe, U. Lepp, B. Niggemann, et al Allergo J 2009;4: 267

Testing for IgG4 against foods is not recommended as a diagnostic tool: EAACI Task Force Report*  
 Stapel SO, Asero R, Ballmer-Weber BK, Knol EF, Strobel S, Vieths S, Kleine-Tebbe J.
 Allergy 2008 July;63(7):793-796.

Unproven techniques in allergy diagnosis.  
 Wuthrich B.
 J Investig Allergol Clin Immunol 2005;15(2):2-90

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Swine flu vaccination controversy in egg allergy

Saturday, October 17th, 2009

There has recently been a lot of debate in the media about safety of vaccines, particularly relating to the MMR (Measles, Mumps & Rubella) vaccination with unsubstantiated links to Autism and Ashbergers Disease.  In addition, the measles vaccine was historically grown on chick embryos, thus running the risk of egg allergen contamination, and consequently recipients could potentially develop anaphylaxis if highly egg allergic. Today the MMR vaccine no longer contains any egg allergen and is absolutely safe to administer to highly egg allergic children.

The influenza and yellow fever vaccines are still cultured on chick egg embryo’s and thus potentially contain egg protein. But the World Health Organisation (WHO) suggests that this is unlikely to be problematic if mildly egg allergic and in those who tolerate egg without anaphylaxis.  In severe egg allergy with anaphylaxis, administration of the conventional influenza and yellow fever vaccinations are contraindicated.

Does the same go for the current Swine Flu (H1N1) influenza vaccine?  I’m informed that Pandemrix currently being promoted to prevent the second wave of the Swine Flu pandemic is also cultured on chick egg embryos. Fortunately there is an alternative Swine Flu vaccine called Celvapan which is not cultured on egg and therefore safe to give to egg allergic individuals. But the Celvapan vaccine does not contain the immunity enhancing adjuvant Squalene and therefore requires 2 doses 3 weeks apart.  Celvapan is also the WHO preferred adjuvant-free Swine flu vaccine to be given during pregnancy.

Annual Flu vaccines are routinely recommended for asthma sufferers as they are generally more prone to viral illnesses, influenza and chest complications.  But Asthma sufferers are also a greater risk group for anaphylaxis if concomitantly egg allergic and inadvertently given the egg cultured flu vaccine. If in doubt, 1/10th of the vaccine should be administered under medical supervision as a test dose followed by the 9/10th balance if no reaction occurs within 30 minutes. 

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Can worms prevent allergies?

Saturday, October 17th, 2009

The current epidemic of allergic disease seems to be in part related to living in a much cleaner more sterile environment together with a lack of parasitic worm infestations. This leads to an early switch in the infant’s immune systems to reacting in a more allergy prone (TH2) manner and less of a bacteria and viruses (TH1) targeting manner.

 In a recent study published in Clinical and Experimental Allergy, investigators found that if mice had their gut infested with parasitic worms, they developed fewer food and airway allergies, but the parasites gave no protection from skin allergies. This is the first evidence that intestinal worms can actually modulate the immune system and “protect” against developing allergies.

A similar study on Vietnamese children showed that if they were treated to eradicate their parasitic gut hookworms, they became much more likely to develop house dust mite allergies and asthma.

Reference: Gastrointestinal nematode infection interferes with experimental allergic airway inflammation but not atopic dermatitis. Hartmann S, Schnoeller C, Dahten A et al. Clin Exp Allergy 2009 (39) 1585-1596.

http://news.bbc.co.uk/2/hi/health/8268584.stm

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Asthma reliever Salbutamol may not work!

Saturday, October 17th, 2009

Salbutamol is the mainstay of treating acute asthma and relieving wheeze. Some children may not respond to this medication.  Up to 100,000 children – 13% of all children with asthma – carry two copies of a gene that renders the blue inhaler drug salbutamol ineffective.

If these children need to use their “reliever” inhaler daily they are 30% more likely to suffer an asthma attack than others, a UK research study shows.

Fortunately it is possible to test for the gene change using a simple mouthwash.

http://news.bbc.co.uk/2/hi/health/8292915.stm

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Peanuts allergy cure is here

Saturday, October 17th, 2009

In a recent peanut allergy study at Addenbrookes Hospital in Cambridge, traces of peanut flour were used to desensitise 18 highly peanut allergic children. At the end of the study conducted in a controlled hospital environment, they were able to consume 12 peanuts each without any allergic reaction. The study involved eating minute trace amounts of peanut flour mixed with food or drinks on a daily basis to slowly induce peanut tolerance.  Then at regular 2 weekly intervals the peanut flour dose was doubled so that by the 10th hospital visit, they each ate 5-6 peanuts each without reacting on allergy testing. But to maintain thispeanut tolerance they will have to continue eating peanuts regularly on a daily basis, otherwise they may lose this tolerance and their peanut allergy recur.

WARNING: This was a highly controlled study in hospital and peanut allergic children should not be given peanut flour unsupervised!

http://news.bbc.co.uk/2/hi/health/7899383.stm

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Should Allergy Testing be done in Pharmacies?

Saturday, October 17th, 2009

The British Society for Allergy and Clinical Immunology (BSACI) has recently raised concerns about allergy testing in pharmacies.

They site a major problem being that pharmacy training involves education about medicines, not about clinical disease, patient history taking, psychology etc. This means that pharmacists do not know what the possibilities for diagnosis are in patients who present with, say, a blocked nose. (more…)

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