Immunologic and absorptive tests in celiac disease: can they replace intestinal biopsies?

The sensitivity and specificity of several immunologic and absorption tests were determined in infants with celiac disease (31 male, 39 female; median age, 2.6 years) in different phases of the disease and in a group of control subjects with chronic diarrhea of different etiologies (32 male, 28 female; median age, 1.2 years). Intestinal biopsy was performed both in the patients and in the controls as a 'gold standard' for the diagnosis. The anti-gliadin antibody (AGA) IgG values showed a sensitivity of 89% and a specificity of 47%; AGA IgA were 69% sensitive and 92% specific; anti-endomysial antibodies (EmA) were 100% sensitive and 97% specific; the xylose test was 71% sensitive and 53% specific; and the steatocrit test after a standard fatty meal was 73% sensitive and 42% specific. The authors conclude that the absorption tests cannot be used successfully in screening for celiac disease, owing to their low specificity. In contrast, EmA behavior was always in accordance with histologic findings in the various phases of celiac disease, and we would advise their use combined with AGA to obtain a sensitivity and specificity of 100%.