Sensitivity of antiendomysium and antigliadin antibodies in untreated celiac disease: Disappointing in clinical practice

OBJECTIVE: We have undertaken a study to assess the efficiency of serologic al tests in the diagnosis of celiac disease (CD) during the period January 1, 1994 to January 7, 1997. Our aim was to evaluate the sensitivity of IgA antiendomysium (EMA) and IgA antigliadin (AGA) with regard to the degree of histological abnormality in biopsy specimens of small intestine in untreat ed celiac disease patients and first-degree relatives. METHODS: The study population comprised 101 cases: 85 untreated celiac pati ents and 16 first-degree relatives with a mean age of 42 yr (range, 2-76 yr s). Sixteen of 85 were excluded from study because they did not satisfy the study or diagnostic criteria of CD. EMA and AGA have been compared with th e degree of villous atrophy (VA) in 69 celiac patients and 16 relatives acc ording to the Marsh criteria of 1992. We divided the Marsh III histology in to three subgroups as follows: Marsh IIIa (partial VA), Marsh IIIb (subtota l VA). and Marsh IIIc (total villous atrophy). RESULTS: The specificity and positive predictive value of EMA for CD was ex cellent, because all EMA-positive patients (n = 42) were diagnosed with CD. The sensitivity of EMA, however, differed between CD subgroups; in patient s with total VA, the sensitivity of EMA was 100% (17/17). However. in patie nts with partial VA (Marsh IIIa), the sensitivity of EMA was disappointing, only 9/29 (31%). Three of 72 celiacs with Marsh IIIb and Marsh IIIc had Ig A deficiency and were excluded from the study. Elevated AGA has been detect ed in the sera of 39 of 69 (62%) patients. A combination of EMA and AGA tes ts showed a sensitivity of 76% (53/69). None of 16 first-degree relatives w ith Marsh I-II had positive EMA. CONCLUSIONS: Interpretation of negative serology needs great awareness. Alt hough EMA sensitivity in total villous atrophy is excellent, in partial vil lous atrophy the sensitivity of EMA appears to be disappointing. Our experi ence shows that EMA and AGA have only limited value in screening programs f or CD. (C) 1999 by Am. Cell. of Gastroenterology.