Am J Gastroenterol. 2002;97(11):2702-2704, 2785-2790
Using a community-based population the researchers screened the blood of 1,000 consecutive subjects (age 16 to 71 years, 497 women) using the three tier classic screening which looks at IgG and IgA antigliadin antibodies, followed by endomysial antibodies (EmA) and total serum IgA in positive patients, and finally at intestinal biopsies of patients with positive EmA. The study screening protocol consisted of the use of a commercial guinea pig anti-tTG antibodies and total serum IgA, the with EmA (IgA and/or IgG) for positive patients followed by intestinal biopsies.
The classic screening found five patients who were eligible for intestinal biopsy, and celiac disease was confirmed in all five. The study group yielded the five patients identified in the classic screening, plus two more with positive IgG antigliadin antibodies and normal total serum IgA (both were positive for EmA).
Juan C. Gomez, MD, and colleagues from San Martin Hospital in La Plata, Argentina write: "Our data showed that a new screening protocol using [anti-tTG] as first line followed by endomysial antibodies is a cost-effective screening and yielded more realistic figures of prevalence for celiac disease in a community setting than the classic three-level sequential evaluation using antigliadin antibodies." In addition to being more sensitive than the classic method of detection, the new screening protocol is cheaper: $3,006 per new patient detected vs. $4,687. Further: Although we still did not perform intestinal biopsy on all those subjects with positive anti-tTG tests but negative EmA, current evidence appears to suggest that the addition of EmA to the seropositive anti-tTG patients might have a key role in the simplified screening avoiding unnecessary biopsies, although the researchers still recommend using a biopsy to confirm diagnosis until the new protocol can be standardized.
In conclusion: We recommend using the anti-tTG as the initial test in both population screening studies and for individual cases suspected of having celiac disease on the basis of symptoms or conditions associated with the condition...(T)hose with positive results should be tested for EmA as a second step in the screening process and, if positive, should undergo an intestinal biopsy for confirmation of the diagnosis.