My daughter's pedi GI said they never order AGA IgG (but they do send AGA IgA)...he said the AGA IgG is worthless. I know from these forums it isn't worthless, but why? How does that value help with the diagnosis of celiac? I'd like to be informed for the next time I speak with him. Thanks!
QUOTE (stolly @ Feb 27 2008, 10:45 PM) 
My daughter's pedi GI said they never order AGA IgG (but they do send AGA IgA)...he said the AGA IgG is worthless. I know from these forums it isn't worthless, but why? How does that value help with the diagnosis of celiac? I'd like to be informed for the next time I speak with him. Thanks!
http://www.celiacdiseasecenter.columbia.ed...C05-Testing.htm
This might be helpful.
Here is some informaton that may be of use to you.
http://www.americanceliac.org/diagnosis.htm
IgG is generally relied upon when one is IgA deficient. It is less specific than the IgA, but is more sensitive. It can help form a part of the total picture in the celiac panel.
http://www.americanceliac.org/diagnosis.htm
QUOTE
What are the different antibody tests available?
The blood tests can be divided into 2 different types of antibodies: those which are “anti-gluten”, and those that “anti-self”. The “anti-gluten” antibodies are the anti-gliadin IgG and IgA. Ig stands for “immunoglobulin” or “antibody”. The “anti-self” antibodies are anti-endomysial IgA and anti-tissue transglutaminase IgA.
***
Antigliadin antibodies
The antigliadin antibodies IgG and IgA recognize a small piece of the gluten protein called gliadin. These antibodies became available during the late 1970’s and were the first step towards recognizing CELIAC DISEASE as an autoimmune disorder. Antigliadin IgG has good sensitivity, while antigliadin IgA has good specificity, and therefore their combined use provided the first reliable screening test for CELIAC DISEASE.
The blood tests can be divided into 2 different types of antibodies: those which are “anti-gluten”, and those that “anti-self”. The “anti-gluten” antibodies are the anti-gliadin IgG and IgA. Ig stands for “immunoglobulin” or “antibody”. The “anti-self” antibodies are anti-endomysial IgA and anti-tissue transglutaminase IgA.
***
Antigliadin antibodies
The antigliadin antibodies IgG and IgA recognize a small piece of the gluten protein called gliadin. These antibodies became available during the late 1970’s and were the first step towards recognizing CELIAC DISEASE as an autoimmune disorder. Antigliadin IgG has good sensitivity, while antigliadin IgA has good specificity, and therefore their combined use provided the first reliable screening test for CELIAC DISEASE.
IgG is generally relied upon when one is IgA deficient. It is less specific than the IgA, but is more sensitive. It can help form a part of the total picture in the celiac panel.