Journal Club: Antibody testing tied to increased incidence of celiac disease

Investigators at a hospital in Alberta, Canada, set out to determine the effect of immunoglobulin A endomysial antibody (IgA-EMA) testing on the incidence and clinical presentation of childhood celiac disease. They divided patients into 2 groups based on when they were referred for possible celiac disease: from 1990 to 1996 (before IgA-EMA testing was introduced) or from 2000 to 2006 (after testing began). They then compared incidence and clinical presentation data for the 2 groups, which included a total of 266 children (aged up to 18 years).

The annual number of diagnoses of celiac disease increased 4-fold over the 16-year period, from 6 to 28 cases per year. The median age at diagnosis also increased, from 2 years in the pretesting group to 9 years in the testing group. The estimated incidence of celiac disease increased from 2 cases per 100,000 per year in the pretesting group to 7.3 cases per 100,000 per year in the testing group.

Celiac disease presentations also changed during the study period. Classic celiac disease presentations decreased from 67% in the pretesting group to 19% in the testing group, although the incidence of classic celiac disease did not change significantly. In the testing group, 13 previously unrecognized clinical presentations were observed in 98 children, including 35 with a family history, 18 with abdominal pain, and 14 with type 1 diabetes. The frequency of Marsh IIIc lesions decreased from 64% in the pretesting group to 44% in the testing group. Classic celiac disease remained predominant in the testing group in children younger than 3 years, whereas atypical gastrointestinal and silent presentations (identified through testing because of a family history or a celiac disease-associated condition) predominated in older children (McGowan KE, et al. Pediatrics. 2009;124[6]:1572-1578).

Celiac disease is out there. It has been underdiagnosed in the United States, especially in its atypical forms. Heightened awareness and development of improved screening tests have brought many new cases to light. Keep celiac disease on your differential diagnosis for a wide variety of presentations, including unexplained abdominal pain.-MB