<<Disclaimer: Verify this information before applying it to your situation.>> Hi Everyone I received several responses to this question. Many, many people asked for a summary, which tells me that there are a lot of us who really don't understand the blood tests related to Celiac. I have cut and paste the responses which pointed to web sites for information. I haven't checked any of these sites yet - so I don't know whether or not they're helpful. (I wonder if the 'student' who recently posted an IgG/IgA question on this list will share his/her report with us??) Also - a lot of folks stated that the new Ttg test is more reliable (but not widely available). ____________________________________________________________________ ***Check out the All Allergy Net at http://allallergynet/ for lots of great, specific information, and go to the related http://www.allergysa.org/GIF/handbook.jpg for everything you needed to know about allergies and food intolerances and then some! Both of these are wonderful resources and under-stated (or never stated!) on this list, ,so if you do a summary, please be sure to mention them. They're really helpful at all levels. *** A good site: http://www.fastlane.net/homepages/thodge/DIAG-TST.txt It might be here, if you haven't seen it already. ***I just saw Dr. Horvath speak last weekend (he's with U MD at the center for celiac research)....it is my impression that the best test is the new Ttg (tissue trans-glutaminase) which actually tests for the presence of the "thing" that the anti-endomysial antibodies are reacting to. (clear as mud, right?) Unfortunately, he also mentioned that u.s. labs aren't standardized and not reliable...maybe if you can track down the U. MD. program you could have blood drawn and sent there for testing....they are trying to gather data on relatives of celiacs. ***There is a new, more accurate blood test called the tTG or tissue Trans Glutamanase. It is 98% accurate for Celiac Sprue, according to Dr. Fasano, head of the Celiac Center at University of Maryland, who was the guest speaker at a meeting of CSA/GC (greater Chicago chapter) recently. ***Check out www.celiac.com You can also use the search feature of your browser to find sites about celiac and narrow the search to antibody testing. You can also get info from www.celiacenter.org Thsi si Dr. Fasano's site at U. of Md. where he is doing the reserch with blood tests to determine the prevalence in the U.S. ***What I've found from my research on IgE and IgM is this: IgE is the antibody measured to determine allergies, found in mast cells and mucus membranes. IgM, onthe other hand, is the antibody produced when challenged by antigens and is present most oftenin delayed food reactions or responses to viral or bacteria infections. ....