<<Disclaimer: Verify this information before applying it to your situation.>>

Any information is for general medical education and should not be
applied to a specific patient's problem without that patient discussing
it with his/her physician.

There have been a number of questions/postings on serologic blood tests
for celiac disease.

These tests listed below have been around for sometime.
   Endomysial antibodies ( IgA)
   Reticulin antibodies ( can be IgA and IgG)
   Gliaidin antibodies ( can be IgA and IgG)

The first 2 are antibodies directed against tissue.  The gliadin
antibodies are directed against wheat proteins.

These tests have been used for several purposes:
   screen large populations for hidden celiac disease.
   test individual patients for celiac disease in whom it is suspected by
      the doctor,
   follow up for healing/improvement of the disease.

There is a lot of medical info published on these tests.

Firstly, they are not perfect or even close to it.   No test is perfect
not even the biopsy.

The levels of antibody drop with exclusion of gluten from the diet
(both gliadin and the connective tissue antibodies).  This point is
really important!!  If someone has excluded gluten from their diet for
a while (weeks to months) and then goes to the doctor and asks for a
test for celiac disease,  the test may be negative.  This negative test
does not tell that the person does not have celiac disease.

Most labs in the US do well in comparison but they are not the same in
how they report the results.  Think of the analogy of distance
measurements:
   Miles
   kilometers
   light years
   Cubits
   hands
these are all different ways of expressing distance.

However that analogy is not quite accurate because while you can convert
the distances from one measure to another, you cannot convert the
measures used in the lab testing for celiac disease from one lab to
another.

Usually a positive in one lab is a positive in another.

Joe Murray MD
University of Iowa