The abstract below will be published in the April, 1996 issue of Gastroenterology. It was accepted for poster presentation for the Annual meeting of the American Gastroenterological Association. The poster section will be on May 22, 1996 (12-2:30 PM) in Hall D, at the Moscone Center, San Francisco, CA.
Several epidemiological studies in Europe using antigliadin (AGA) and endomysium antibodies (EmA) for initial screening report the prevalence of celiac disease (celiac disease) to be about 1 out of 300 in the general population. The EmA is most reliable for screening with greater than 99% positive predictive-value in subsequent biopsy-proven cases. There are no comparable scientific data for the USA yet, and celiac disease is considered rare in this country. Lack of awareness could result in significant under-diagnosis of celiac disease in the USA.
Aim: To determine the prevalence of positive serological tests for celiac disease in healthy blood donors in USA.
Methods: Sera from 2000 healthy blood donors were screened for IgG and IgA AGA using ELISA test. All those with elevated AGA levels (IgA >18 units or IgG >25 units) and those with high normal levels (IgA 10-18 units or IgG 15-25 units) were tested for EmA by indirect immunofluorescence using both monkey esophagus (ME) and human umbilical cord (HUC).
Results: The mean age of blood donors was 39 years, with 52% being men, 87% being Caucasian, 11.5% African American, and 1.5% Asian. 95 (4.75%) of the subjects had elevated AGA levels (IgG and/or IgA). A total of 44 (2.2%) had an elevated IgA AGA. Of these, 7 were also positive for EmA. No patient with only raised levels of IgG AGA was positive for EmA. Of the subjects with high normal AGA levels, one (IgA 12 units, IgG 1.8 units) was positive for EmA. Among the total of 8 subjects with elevated EmA levels, seven were Caucasian and one was African American. There was a 100% correlation between ME and HUC for positivity (8 samples) and negativity (288 samples).
Conclusions: The prevalence of elevated EmA levels in healthy blood donors in USA is 1:250 (8/2000). This is similar to that reported from countries in Europe where subsequent small intestinal biopsies have confirmed celiac disease in all those with EmA positivity. Based on a positive predictive value of >99% for celiac disease in patients with elevated EmA levels, it is likely that the 8 blood donors identified in this study have celiac disease. These data suggest that celiac disease is not rare in the USA and may be greatly under-diagnosed. There is need for a large scale epidemiological study to determine the precise prevalence of the disease in the USA.