<<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