<<Disclaimer: Verify this information before applying it to your situation.>> Judy C. Hettena Wright <hettenawright @ COMPUSERVE.COM> wrote: >In March, 95 I had what's called an ASI test by Diagnos-Techs lab ... > In January, 96, they ordered a second test, but this time, they also > asked the lab to check for"ANTI-GLIADIN SIgA" and the test came back > positive. They said "you probably have celiac disease, try the diet, > no need to have the biopsy,this test is very good". It is my understanding that the Saliva (SIgA) test has positive results for 15% of the population, the great majority of which do not have celiac disease. In my non-medical, non-expert opinion, it would be a mistake to use either this test, or the ELISA, to diagnose Celiac Disease. At present, only a biopsy is accepted as proof of CD. The endomysial blood test is far more accurate than the saliva test, and some people use it for diagnosis instead of a biopsy, even though it is not accepted medical practise. Here is a section from our DIAG-TST file which covers SiGA. To get the full file (which also covers endomysial and biospies), send an email to [log in to unmask] with the body GET CELIAC DIAG-TST: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 2. Saliva Test The following section represents questions and comments on the saliva test and its possibility as an antibody detection tool. Back on 7 Feb 1996 Elizabeth Welch <[log in to unmask]> asked: EW> Has anyone heard of IgA antibody testing done using saliva ("spit EW> test")? ..(rest deleted) And (name removed at the request of the poster) replied: > ....I know about that test--I have had the secretory IgA test from > Diagnos-Techs(it is specific for anti-gliadin antibodies). Dr. > Busher, M.D. of Bellevue, WA regards it as an excellent test. <snip> > > My ex-husband is very good friends with Dr. Ilias, > the research biochemist who developed this test and owns > Diagnos-Techs....I was told was that if my diet was scrupulously > gluten free, my IgA levels would drop, but probably not below the > 40's. When the levels get high, they never drop to normal ranges > again....All people have a titer of anti-gliadin anti-bodies on this > test, because gluten causes a small amount of villi damage in > everybody. <snip> > > I asked hard questions about the reliability of this test, and was > assured that it is highly reliable, with essentially no false > positives (well below 1%). I can't remember the rate of false > negatives....but it is also very low....It is a relatively new test. The Listowners forwarded this information to cel-pro and asked for advise. We received several replies which will be summarized below. In addition, Dr. Ilias provided me with enough test kits to try out my whole family. I can report that despite the above statement " When the levels get high, they never drop to normal ranges again"-- My Celiac son, whose endomysial, reticulin and gliadin antibodies were very high prior to his GF diet, had a single digit SIgA level on Dr. Ilias' saliva test. My whole family was well within the normal range, but his was the lowest! For those of you who want more information about the test, the labs' phone number is (206) 251-0596. The test only costs $30. It was more difficult to get my children to properly deliver the saliva than I had expected. Unlike a blood draw, this requires active cooperation. Dr. Ilias told me that in the 12,000 tests he has done to date he consistently gets about 14% to 15% positive results, which is about 35 times greater than the incidence of celiac disease in Europe (1:250). Thus, the test may be a screen for general allergy or intolerance to gluten, not just formal Celiac. Before reviewing some of the comments about the test itself, I wanted to forward a comment to this statement in the reply post: LW> ...All people have a titer of anti-gliadin anti-bodies on this test, LW> because gluten causes a small amount of villi damage in everybody. On this point Don Kasarda replied: DK> I don't know anything about the saliva test, but I am not personally DK> aware of any scientific evidence for the above statement that gluten DK> causes a small amount of damage to villi in everybody. As for the test itself, those who commented on it made it clear that the test has not been validated as being either sensitive or specific enough for diagnostic work in Celiac Disease. It appears to be one of a number of a number of unproven, and not-completely-tested alternatives to the current state of the art endoymsial/reticulin/gliadin panel, which approaches 100% accuracy when done by an experienced lab. >From Erkki Savilahti, M.D., who was one of the authors of a study comparing the saliva test to the current serology tests in DH: ES> Our study (Eur J Oral Sci 1995;103:280-4 Patinen et al.; Salivary ES> and serum IgA antigliadin antibodies in dermatitis herpetiformis) ES> did not find salivary antibodies very useful in dermatitis ES> herpetiformis; in fact IgA antigliadin antibodies in saliva were not ES> increased in any of the 10 untreated patients and there was no ES> change after the introduction of gluten free diet. ES> ES> Altogether the measurement of salivary antibodies is plagued with ES> many drawbacks; it is difficult to stimulate and collect resulting ES> in very variable levels. Serum tests for example to study ES> endomysium antibodies may be done on a small sample taken by skin ES> puncture and is acceptable for children. Moreover, the specificity ES> and sensitivity of these antibodies are superior to determination ES> of gliadin antibodies: in a submitted manuscript we found the ES> sensitivity for umbilical cord antibodies to be 0.94 and specificity ES> 1.00 in a large material of pediatric patients. Dr. Karoly Horvath called Dr. Ilyia to get more information about the saliva test, and send the following email: KH> I talked with Dr. Ilyia about the saliva antibody test. Evidently, KH> he states that this is a very helpful test for people looking for KH> any help for the gastrointestinal problems. Several patients who had KH> increased saliva antibodies reacted well for gluten withdrawal. KH> This sounds great. However, from methodological point of view there KH> are several steps to validate the test: KH> KH> - There is no data about the specificity and sensitivity of this KH> test in celiac patients. If somebody introduces a new test it KH> should be compared with the clinical diagnosis based on other KH> test(s) with high specificity and sensitivity or with a KH> pathologic diagnosis (e.g. intestinal histology in celiac KH> patients or skin biopsy in patients with DH). This saliva test KH> was compared only with the serum antigliadin antibody levels of KH> the same patients. The clinical correlation of the results KH> based on the patients subjective response to elimination diets. KH> Dr. Ilyia states that the saliva test is positive when the serum KH> antibody level is not elevated (returned to the normal level). KH> KH> - They have not compared yet their test results with endomysium KH> antibody titers. They have not compared the results with the KH> histology of celiac patients. KH> KH> Dr. Ilyia mentioned to me that he has talked with Joe Murray, KH> and they are planning to perform studies with the participation KH> of 22 patients with celiac disease. ... KH> KH> - They did not evaluate the antibodies in healthy people, and KH> there is no data on the percentage of normal population, who may KH> have increased levels without celiac disease (normal control KH> group)... KH> KH> - There is no data whether people with other documented KH> gastrointestinal diseases (e.g. Crohn's disease) have salivary KH> antibodies more frequently than the healthy controls (GI control KH> group).... KH> KH> I tried to focus on questions which are addressed when somebody KH> comes out with a new test. All these issues have been clarified for KH> the serum serological tests between 1985 and 1991. That is why we KH> have data about the specificity, sensitivity, positive and negative KH> predictive value of the celiac serum serological tests. For a real KH> judgement of the saliva test it should undergo the same steps of KH> evaluation. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Bill Elkus Los Angeles