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Vaccine new treatment for allergies?

May 27, 2004

A vaccine against allergies. This may be the eventual result of research at Uppsala university in Sweden. New findings are presented by Anna Ledin in her doctoral dissertation. She vaccinated dogs and rats against their own IgE antibodies, and shows that their allergic symptoms diminished.

The type of antibody called IgE is part of the body's defense against parasites, but today it is best known for its key role in allergic reactions. IgE is what brings about an allergic reaction. Normally it constitutes 0.02 % of all antibodies in the blood, but people with allergies can have up to ten times as much. The best way for a person with allergies to avoid reactions is to avoid the substance that triggers the allergies. But if you are allergic to pollen it is not easy to avoid all the pollen produced by blossoming birch trees, for example, which can lead to asthma, hay fever, and/or eczema.

Anna Ledin belongs to a team of scientists at Uppsala University that is developing vaccines against allergies, under the direction of Professor Lars Hellman. Her dissertation is part of this project. She presents a new form of treatment for allergies in her study. By producing and injecting an IgE vaccine that looks like IgE, she demonstrates that the body perceives the vaccine as something alien. Antibodies are then produced to fight both IgE and the vaccine, bringing down the levels of IgE in the blood and reducing the allergic symptoms. The allergy vaccine has been tested on rats and dogs, and the results indicate a clear reduction of IgE levels after vaccination. Dogs are one of the few animals that have allergic reactions like humans, but it has been unclear just how IgE levels are related to their symptoms. A new method for monitoring IgE levels in the blood of dogs was developed by the research team, and it was found that dogs have extremely high levels of IgE, regardless of whether they were healthy or had allergic eczema, autoimmune disorders, or skin parasites. This makes it problematic to diagnose allergies merely on the basis of IgE from dog blood. What's more, IgE was measured from three sets of puppies, and, unlike mature dogs, the puppies evinced low levels of IgE.

What causes allergies then? It is certain that both environmental and genetic factors play a role. But it has not been determined exactly which genes are involved or to what extent they are involved. Therefore Anna Ledin and the research team examined how a part of one chromosome, containing many different genes, is involved in the regulation of IgE in rats. That particular chromosomal region has previously been implicated in the susceptibility of rats to developing pain in their joints in a model for arthritic rheumatism, and they found that it also affects IgE levels in rats. It remains to be studied whether this chromosomal region also impacts IgE levels in humans.

Title of dissertation: More or Less IgE
Link to presentation of the dissertation: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4254

Vetenskapsrådet (The Swedish Research Council)