I enjoyed reading J. Murrays comments related to the diagnosis of celiac disease and agree that taking multiple biopsies is still the gold standard of diagnosing celiac disease. However, I am sure he will agree that there are limitations in the histopathological methods of diagnosing celiac disease.
As we know, histological features occur in continuum, with flat lesions at one end of the spectrum and a mucosa with normal villous and crypt architecture but abnormally high density or count of villous intraepithelial lymphocytes at the other, which may be reported normal.
In addition, patients with silent, atypical or occult celiac disease 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 celiac disease and DH. Our studies indicate and corroborate with the others that the AGA test is a sensitive but not very specific marker of celiac disease. 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 celiac disease could be induced on an increased gluten intake indicating thereby the sensitivity of EMA tests.
The following table is a summary of our studies on the utility of various serological methods of diagnosing celiac disease. Comparison of Sensitivity, Specificity, Positive and Negative Predictive Value of AGA, ARA, and EMA in Active Celiac Disease:
|% of Sensitivity||% of Specificity||Predictive Value % Pos||Predictive Value % Neg|
I shall be glad to discuss the utility of serological methods in diagnosing celiac disease with anyone interested.