<<Disclaimer: Verify this information before applying it to your situation.>> bs"d Summarization of my original question: I received first lab results back, after being on a low to no gluten diet for 4-5 years. I was confused by the first term, could not find out what it referred to exactly, as there are several aliases. So I put the question to this community: ”What do the following terms mean?” Reticulin Abs, S ARA IgA Reticulin Antibody IgG Reticulin Antibody I then proceeded to describe some of the Mayo Medical Laboratories Celiac Panel descriptions, complete with links. A member responded that she has a friend, Holly, a librarian who works for the NIH and trains people on how to use the free on-line educational resources available thru the NIH and the National Library of Medicine. She had sent my email to Holly, who replied: Interesting. When I searched on the specific tests, I got little. When I backed up and entered Celiac - there were very informative links to the tests and their results. http://www.nlm.nih.gov/medlineplus/celiacdisease.html One of the links from this page goes to a website called "Lab Tests Online: a public resource to clinical lab testing form the laboratory professionals who do the testing." http://www.labtestsonline.org/understanding/analytes/celiac_disease/test.html LOTS of good definitions there. (Cool site, got to remember this one.) I highly recommend folks starting at MedlinePlus! Let me copy and paste for you. (wow, very kind) http://labtestsonline.org/understanding/analytes/celiac_disease/sample.html Deborah’s note: Due to space restrictions I will only include the paragraphs Holly copied that are very specifically relevant to my question. Because of all the reading I'd done on my own via internet and some books looking for this answer, as well as some repetitiveness and irrelevance of some of the material to my specific question, I missed the importance of some of these paragraphs Holly had sent to me. That's a word to the wise. She kindly pointed them out to me. # Anti-Reticulin Antibodies (ARA), IgA: Anti-ARA is not as specific or sensitive as the other autoantibodies. It is found in about 60% of celiac disease patients and about 25% of patients with dermatitis herpetiformis. Each of the celiac blood tests measures the amount of a particular autoantibody in the blood. For each test, both IgG (Immunoglobulin G) and IgA (Immunoglobulin A) antibodies can be measured; however, few laboratories offer IgG tests other than for gliadin. IgG and IgA are two of the five classes of antibody proteins that the immune system creates in response to a perceived threat. In general, the IgA antibody is more specific for celiac disease (since IgA is the type of antibody made in the intestine) and is measured almost exclusively. IgG versions may be ordered either to complement the IgA testing and/or ordered because someone has an overall deficiency in IgA. This happens about 2% of the time with celiac disease and can lead to some false negative test results. From: http://labtestsonline.org/understanding/analytes/celiac_disease/test.html Positive and indeterminate celiac disease tests are usually followed by an intestinal biopsy. A biopsy is used to make a definitive diagnosis of Celiac disease. That leads back to the question of "faint positive" she was asking about". Hope this helps. Holly. _______________________________________________________________________ And yes, that was wonderfully helpful. Hit the spot!!! To summarize, if I understand this correctly: It seems that if the lab report lists ARA, or “reticulin antibody” as one component having been tested, this is the same component in the lab test as IgA reticulin antibody. Thus, when being tested for Celiac disease, if someone’s lab report does NOT specify which immunoglobulin is being tested by the abbreviation IgG, then it is IgA. This is important, because IgA reticulin antibody is specific, but not sensitive. Regarding the reported specificity of IgA reticulin antibody, from other sources that I have read, it will not show up in approximately 40% of those with Celiac disease. It considered reliable predictor for Celiac disease, approximately 60% of the time. Some consider it a very reliable predictor in the case of latent Celiac disease. So, if you have a positive test result for “IgA reticulin”, alias “antireticulin antibody”, alias ARA, alias “reticulin antibody” you have a higher probability of having either active or latent Celiac Disease. I'm not clear on which one it is considered an accurate predictor for at this point. The source that Holly pointed me to, referenced above only says that it is more specific than reticulin antibody IgG. A couple sources I found in my quest: http://www.jpgn.org/pt/re/jpgn/fulltext.00005176-199709000-00025.htm;jsessionid=Lt2CKLvpM2xzQsPjv1mGBQX1cmYSph4s7x3LxHhdQ3p1FXvk1vDF!526656812!181195628!8091!-1 http://www.gluten-free.org/hoggan/kumar.txt Regarding the second link, I have been informed by a member of this community that Hoggan is not considered "mainstream" in his views, so do keep that in mind when reading his work. In my opinion, we need the mainstream and non-mainstream folks in this game. Thank you Carol and Holly. Feedback on whether I understand this correctly or not is always appreciated. Visit the Celiac Web Page at Http://www.enabling.org/ia/celiac/index.html Archives are at: Http://Listserv.icors.org/SCRIPTS/WA-ICORS.EXE?LIST=CELIAC