What are the follow-up tests that I should get to monitor celiac disease, and what can I do if my tests are abnormal?
Standard follow-up tests to monitor gluten-free diet adherence routinely are antibody blood tests. These typically include at least the tissue transglutaminase (tTG) IgA since it appears in about 98 percent of those with active celiac disease. The tTG IgG also may be checked if IgA deficiency, a condition in which individuals do not make or have very low blood levels of IgA antibodies, is a concern. Diaminated gliadin peptides (DGP) IgA and IgG and the endomysial antibody (EMA) may be also ordered, although less commonly. Incidentally, the antigliadin peptide antibodies (AGA), not to be confused with the DGP antibodies, are obsolete.
When antibody testing is done for monitoring, the same lab used for the blood tests at diagnosis should be used for follow-up because there are no universal normal standards and a comparison of the change in each patients’ results is what is important more so than the absolute values. Although the antibody blood tests are the best we have to assess celiac disease improvement after starting a gluten-free diet, they were really designed for diagnosis. Consequently, ‘normal’ test results can provide a false sense of wellbeing as they cannot detect occasional harmful transgressions in the diet, hence leading healthcare providers and patients to believe they are following the gluten-free diet sufficiently when that’s not necessarily the case.
Until recently, there have been no reliable tests for evaluating dietary compliance. However, a validated rapid at-home stool and urine test for gluten was recently launched in the US.. The test, Gluten Detective can determine if someone has consumed as little as 50 milligrams of gluten within the previous 2-3 days using stool, or 500 milligrams or more over the previous 24 hours using urine.
If blood tests or the stool test have results that indicate gluten is getting into the diet, you should consult an experienced registered dietician (RD/RDN). A dietitian can help get to the bottom of the problem by providing comprehensive nutrition education or an update on the gluten-free diet with emphasis on eliminating cross-contact. Since the stool test is most likely to reveal if gluten has been consumed in the previous one to seven days, it can help identify the source of short-term gluten exposure. Joining a celiac support group, especially a face-to-face group, along with routine follow up with a dietitian can also help with managing the gluten-free lifestyle. To further manage for psychosocial challenges, especially in social eating settings you may benefit from a counselor or therapist.
Nancy Patin Falini, MA, RDN, LDN Nutritional Graces, LLC Private Practice.
Conducts both face-to-face and virtual nutrition and wellness education and counseling.