>Dear Coralie,
>
>What part does IgG play.
> Can food intolerances cause an IgG
>deficiency? If gluten is a problem, how does it show in your blood, IE which
>part? What is the IgG test and how will it monitor your grand daughters
>diet? If I track all my problem foods and eliminate them will my IgG be normal?
>
/Dear Gina:

My small amount of knowledge about all of this concerns only our experience
with celiac disease.

Antibodies in the blood are made of gammaglobulin protein and are called
immunoglobulins.  There are various classes of these.  IgG makes up the
majority, IgA is a much smaller amount and is present mainly in secretions
of the GI tract.  IgE is involved in allergic responses and is measured to
detect allergic disease.  (Perhaps your allergist could explain the
relationship between your diagnosed IgG deficiency and food allergies.)
These immunoglobulins can be separated out and measured to detect and
monitor responses.

Celiac disease is not considered an allergic reaction.
The celiac panel, at least in the USA, measures four types of antibodies.
Reticulin antibodies (IgA)
Endomysial antibodies (IgA)
Gliadin antibodies  (IgA)
Gliadin Antibodies  (IgG)
These different antibodies have varying sensitivities and specificities,
helpful in screening for celiac disease.  At this time, positive (or
negative) tests are not diagnostic in and of themselves, but assist in
determining who should be biopsied.
In an individual who is highly symptomatic and has a celiac panel with only
IgG response, it is wise to test the IgA level.  If the IgA is normal this
person would not be highly suspect to have celiac.  If the IgA is deficient,
most MDs would probably recommend biopsy if some other diagnosis did not
seem plausable.
For an individual who is IgA deficient(the IgA level is measured and
compared to a standard in the general population), the three tests that
measure IgA will not be elevated and would not be repeated. Therefore once
someone is shown to be IgA deficient, these would not be useful in
monitoring the success of the gluten free diet.  The IgG measurement would
be expected to be useful since it is the only response among these four
tests that such a person would have.  After diagnosis, if all gluten is
successfully removed from the diet, the IgG should return to a normal level,
if it is still elevated after 6 mos. or so, then it is assumed that the
individual is still consuming some gluten which is responsible for the (IgG)
antibody response.

I don't know if this helps at all, this is how it has been explained to
me--but is a small part of the entire picture.
Coralie