I found the information quoted below on interpreting these blood tests, in summary, the specific type of immunoglobulin found in excess in your tests almost always (97% of the time) indicates the presence of celiac disease. Since the predisposition to develop celiac disease is transmitted genetically, if you have the condition then the chances your first order blood relatives (parent [1 of], siblings, children) might have it is increased at least tenfold over a random person on the street.
I have one concern. First I'm very pleased that you are already feeling better on a gluten free diet. The potential problem is that once you begin a gluten free diet the villi in your small intestine will almost certainly begin to heal. If enough time passes between your adopting a GF diet and your endoscopy, then your villi may have healed so much that you would get a false negative result - a finding of normal villi.
It's entirely possible that your villi would not have healed that much in a few weeks, this might not be an issue, but I suggest you contact your doctor ASAP to see if your endoscopy can be moved to a sooner date.
We all have, within our bodies, a family of closely related although not identical proteins which are capable of acting as antibodies. These are collectively referred to as immunoglobulins. Five major types of immunoglobulins are normally present in the human adult. They are IgG, IgA, IgM, IgE and IgD. Each of these is a shorthand way of writing immunoglobulin gamma G (or A or M, etc.) and they each perform a different function in our systems. IgG is the principal immunoglobulin in human serum. It is important in providing immunity in a developing fetus because it will pass across the placental barrier. IgA is the principal immunoglobulin in secretions from respiratory and intestinal mucosa. IgE is a gamma globulin produced by cells lining the intestinal and respiratory tracts. It produces the antibodies associated with most hypersensitivity (allergic) responses. It is associated with asthma, hay fever, etc. IgM is a globulin formed in almost every immune response in the early part of the reaction. IgD is a rare protein present in normal sera in a tiny amount. These designations refer to the type of protein that is carrying the antibody in question. Both IgG and IgA subtypes of anti-gliadin antibody are produced, hence we refer to them as IgG gliadin or IgA gliadin. Collectively they are anti-gliadin antibodies.
Anti-Gliadin Antibodies:
Both IgA and IgG anti-gliadin antibodies (AGA) are detected in sera of patients with gluten sensitive enteropathy (celiac disease). IgG anti-gliadin antibodies are more sensitive but are less specific markers for disease compared with IgA class antibodies. IgA anti-gliadin antibodies are less sensitive but are more specific. In clinical trials, the IgA antibodies have a specificity of 97% but the sensitivity is only 71%. That means that, if a patient is IgA positive, there is a 97% probability that they have celiac disease.[emphasis added SR] Conversely, if the patient is IgA negative, there is only a 71% probability that the patient is truly negative for celiac disease. Therefore, a positive result is a strong indication that the patient has the disease but a negative result does not necessarily mean that they don not have it. False positive results are rather uncommon but false negative results can occur. On the other hand, the IgG anti-gliadin antibodies are 91% specific and have an 87% sensitivity. This means that they will show positive results more readily but there is not as strong a correlation with celiac disease. It is less specific. Patients with other conditions but not afflicted with celiac disease will occasionally show positive results. IgG anti-gliadin antibodies are detectable in approximately 21% of patients with other gastrointestinal disorders. This test might yield false positive results but is less likely to yield false negative results.
Good luck, I hope that at least now that you know what you are dealing with it will help to ease your mind.
The good part is that just by eating a gluten free diet the majority of people with celiac disease see a vast improvement in their health and well being.
