Carbohydrate related allergies - further examples

[Iain Wilson]

Dear All,
  I'm basically a glycoprotein biochemist and I have just started 
a project on plant and insect glycosylation. From what I gather
the literature includes a body of mainly circumstantial evidence
for the role of carbohydrate in allergies. Better defined examples
such as bee venom allergy are recorded, but many papers just mention
crude deglycosylation as the basis for saying that carbohydrate may
have a role. Some here may know that RAST results do indicate
a certain degree of cross-reactivity between plant and insect 
materials - a cross-reacting carbohydrate determinant was 
mentioned by Aalberse et al. some years back. What is the *current* 
view amongst allergy researchers on this? Does anyone know of good
examples of plant/insect carbohydrate allergens? Or is the prevailing
view that protein can account for the cross-reaction between so many
materials? Also, why should there be examples of a disparity between
the specificities of animal IgG and human IgE when it comes to 
carbohydrate - that is, other than the species difference, why should
an IgG antiserum to a plant glycoprotein be apparently directed 
against the carbohydrate, yet in some cases (Japanese cedar pollen, 
for instance) the carbohydrate is not the major epitope for IgE from
allergic patients?

  I normally don't seem to have the time to cover too many newsgroups,
so if you have immediate points in response, do cc: any comments by 
e-mail to me.

  Iain

---------------------------------------------------------------
Iain Wilson                        Institut für Chemie           
Tel: 43-1-47654-6065               Universität für Bodenkultur   
Fax: 43-1-310-5176                 Gregor-Mendel-Straße 33
E-mail: wilson at edv1.boku.ac.at     A-1180, WIEN, Austria

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