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Study Shows that a Strategy of Active Case-finding can Increase Rates of Diagnosis for Celiac Disease

Celiac.com 09/28/2007 - Celiac disease is one of the most common lifelong disorders in western countries. However, most cases in North America remain currently undiagnosed, mostly because they present unusual symptoms and because of the low number of doctors who have a sound awareness of celiac disease.

In a large European survey, the ratio between diagnosed and undiagnosed cases, found by mass serological screening, was as high as 1 to 7 , an effect termed the ‘celiac iceberg’. In addition to having chronic symptoms that might otherwise respond to a gluten-free diet, undiagnosed patients are exposed to the risk of long-term complications of celiac disease, such as anemia, infertility, osteoporosis, or cancer, particularly an intestinal lymphoma.

Celiac Disease is diagnosed by confirming the presence of intestinal damage to the small intestine through a biopsy, along with a clinical response to the gluten-free diet. However, serological markers, e.g., the IgA class anti-tissue transglutaminase (tTG) antibodies, are useful screening tests. The sensitivity and the specificity of the IgA anti-tTG test are 94% and 97%, respectively.

To address the large number of undiagnosed cases, a team of researchers recently set out to assess whether an active case-finding strategy in primary care could lead to increased frequency of celiac disease diagnosis, and to assess the most common clinical manifestations of the condition.

The team was made up of Carlo Catassi, M.D., M.P.H.; Deborah Kryszak, B.S.; Otto Louis-Jacques, M.D.; Donald R. Duerksen, M.D.; Ivor Hill, M.D.; Sheila E. Crowe, M.D.; Andrew R. Brown, M.D.; Nicholas J. Procaccini, M.D.; Brigid A Wonderly, R.N.; Paul Hartley, M.D.; James Moreci, M.D.; Nathan Bennett, M.D.; Karoly Horvath, M.D., Ph.D.; Margaret Burk, R.N.; Alessio Fasano, M.D.

737 women and 239 men, with a median age of 54.3 years, who attended one of the practices participated in a multi-center, prospective study involving adult subjects during the years 2002-2004. All individuals with celiac-associated symptoms or conditions were tested for immunoglobulin A anti-transglutaminase (tTG) antibodies. Those with elevated anti-tTG were then tested for IgA antiendomysial antibodies (EMA). All who were positive for EMA were advised to undergo an intestinal biopsy and HLA typing.

30 out of 976 study subjects showed a positive anti-tTG test (3.07%, 95% CI 1.98-4.16). 22 patients,18 women, 4 men, were diagnosed with celiac disease. In these 22 cases the most common reasons for screening for celiac disease was: bloating (12/22), thyroid disease (11/22), irritable bowel syndrome (7/22), unexplained chronic diarrhea (6/22), chronic fatigue (5/22), and constipation (4/22).

The prevalence of celiac disease in the serologically screened sample was 2.25% (95% CI 1.32-3.18). The diagnostic rate was low at baseline (0.27 cases per thousand visits, 95% CI 0.13-0.41) and rose sharply to 11.6 per thousand visits (95% CI 6.8-16.4, P < 0.001) with active screening.

This study shows that the diagnosis rate for celiac disease can be significantly increased through the implementation of a strategy of active case-finding.

Am J Gastroenterol. 2007;102(7):1454-1460.