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I enjoyed reading J. Murray s comments related to the diagnosis of celiac
disease and agree that taking multiple biopsies is still the gold standard of
diagnosing CD.  However, I am sure he will agree that there are limitations
in the histopathological methods of diagnosing CD.
 
As we know, histological features occur in continuum, with flat lesions at
one end of the spectrum and a mucosa with normal villus and crypt
architecture but abnormally high density or count of villus intraepithelial
lymphocytes at the other, which may be reported normal.
 
In addition, patients with silent, atypical or occult CD may exhibit normal
or mild villous atrophy and histopathology may not be diagnostic.  The best
example would be patients with dermatitis herpetiformis (DH).  As we know,
all DH patients have gluten sensitive enteropathy, but only 60-70% of DH
patients exhibit characteristic histopathology diagnostic of gluten sensitive
enteropathy.
 
In this regard, there has been a constant effort to put forth a simple
serological method that is a specific and sensitive indicator of gluten
sensitive enteropathy.
 
There are basically three antibody markers (ARA, AGA and EMA) that could be
used for diagnosing CD and DH.  Our studies indicate and corroborate with the
others that the AGA test is a sensitive but not very specific marker of CD.
 On the other hand, ARA is very specific but not sensitive.  We described in
1984 the endomysial antibody test and we felt very comfortable reporting that
this EMA test has >99% specificity and sensitivity for gluten sensitive
enteropathy.  We reported cases of DH who were biopsy negative but EMA
positive in which the histopathological changes consistent with CD could be
induced on an increased gluten intake indicating  thereby the sensitivity of
EMA tests.
 
The following table is a summative of our studies on the utility of various
serological methods of diagnosing CD.
 
Comparison of Sensitivity, Specificity, Positive and Negative Predictive
Value of AGA, ARA, and EMA in ActiveCeliac Disease
 
Antibody   Sensitivity %   Specificity %   Predictive Value
                                           Pos. %    Neg. %
Gliadin
   IgG          88              92           88        92
   IgA          52              94           87        74
Reticulin       65             100          100        72
Endomysium      97              98           97        98
 
I shall be glad to discuss the utility of serological methods in diagnosing
CD with anyone interested.
 
Vijay Kumar