Value of serologic markers for clinical diagnosis and population studies of coeliac disease

Background: There is a need for serologic markers in selecting patients with symptoms compatible with coeliac disease for intestinal biopsy and for population screening. Few comparative studies have been done. Methods: Sera from 55 patients with coeliac disease and 65 referents, aged between 8 months and 79 years, were investigated. Anti-gliadin, anti-reticulin, anti-endomysium, and anti-jejunal antibodies were measured. The sensitivities, specificities, and positive predictive values for different disease prevalence levels were calculated. Confidence intervals, rarely used in this type of study, were calculated. Results and Conclusions: In most tests the antibody levels were age-correlated. The highest sensitivities in combination with high specificities were found for IgA anti-gliadin antibodies in children less than 5 years of age and IgA anti-endomysium antibodies in older children and adults. These tests were most useful for testing a population with a high disease prevalence, such as patients with gastrointestinal symptoms, although the results for many tests had overlapping confidence intervals. For screening unselected populations with a low disease prevalence, in which a test with maximum specificity is desired, only anti-endomysium antibodies had sufficiently high predictive value to be of practical use.