Still No Test to Confirm Celiac Mucosal Status Without Biopsy

Celiac.com 03/16/2009 - Current treatment for celiac disease consists of a lifetime gluten-free diet. However, once the diagnosis is made, most people don’t really receive regular follow-up or monitoring of their treatment unless they have some obvious complaint. That’s beginning to change, and more doctors are beginning to advocate long-term celiac care, which includes regular tests to assess dietary compliance.

To accomplish this goal, doctors are working to determine the best program of follow-up treatment. A team of Austrian researchers recently set out to determine which noninvasive test for celiac disease is best for assessing mucosal status in people with celiac disease.

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The research team was made up of doctors Andreas K. W. Vécsei, Ulrike B. Graf, and H. Vogelsang, associated with St. Anna Children's Hospital, Vienna, Austria and the Department of Gastroenterology and Hepatology, Clinic of Internal Medicine III, Medical University of Vienna, Vienna, Austria.

The research team set out to clarify which noninvasive follow-up methods for testing blood serum or intestinal permeability (IPT) – best match the patient’s histology, and whether the accuracy of these tests is affected by the interval between diagnosis and follow-up affects.

The team mined a computer database to compile information from adult patients, diagnosed with celiac disease between December 1989 and July 2006, who underwent follow up via biopsy, IPT, and serological testing via IgG anti-gliadin antibodies (AGA-IgG), AGA-IgA, and endomysial antibodies (EMA).

They measured effectiveness of noninvasive test results based on the presence of villous atrophy upon biopsy. The team divided patients into two groups. The first, group A, comprised patients followed up within 24 months of diagnosis, and group B, comprising patients followed up after 24 months.

In all, the team was able to evaluate forty-seven patients. The tests showed the following results:

Lactulose/mannitol (L/M) ratio showed a sensitivity of 85% and a specificity of 46.2% for mucosal atrophy, while saccharose excretion showed a sensitivity of 60% and a specificity of 52.6%.

AGA-IgA and AGA-IgG showed 15% and 20%, respectively, and both showed specificity of 100%. AGA was of limited usefulness due to low number of positive results. EMA assay was 50% sensitive and 77.8% specific.

In group A (n = 23) L/M ratio performed best in terms of sensitivity (88.9%), whereas EMA achieved a higher specificity (71.4%). In group B, the sensitivity of the L/M ratio decreased to 85.7%, while the specificity of EMA increased to 91.7%.

The team concluded that these results show that none of the non-invasive tests was an accurate replacement for follow-up biopsy in detecting severe mucosal damage.

Until an accurate test is developed, long-term follow-up monitoring of gluten-free status in people with celiac disease will remain difficult to do reliably without biopsy.

Endoscopy 2009; 41: 123-128