Gluten, Fecal, Quantitative

Stool (unpreserved, random)

3 g

1 g

Clean, screw-capped, plastic vial with no preservatives

This Gluten ELISA test is intended for the quantitative determination of Gliadin 33mer in stool samples. This test may be used for the following applications:

• Monitoring Celiac Disease (CD) and non-celiac gluten sensitivity (NCGS) patients for adherence to a gluten-free diet (GFD).

• Monitoring accidental gluten consumption due to mislabeling or food/product contamination.

• Assisting in the diagnosis of a true "refractory" CD that is not related to accidental gluten exposure.^2,4

This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.

Quantitative enzyme-linked immunosorbent assay (ELISA)

<12 ng/mL

Celiac Disease (CD) is a serious, underdiagnosed autoimmune condition that is caused by an immune response to dietary gluten-containing products in individuals with a genetic predisposition to CD.^1,2 It has been reported that in the United States, the cumulative incidence of CD is 1.8% and this number is likely to be underestimation.^1,3 The only available treatment for CD is complete, lifelong avoidance of gluten consumption (known as a gluten-free diet, or GFD).^1,2,4 However, strict compliance with a GFD is very challenging, and a significant subset of patients who are trying their best to adhere to a GFD are not relieved from symptoms and have persistent biopsy-detectable damage of the mucosal layer in their gastrointestinal tract.^1,4 One study found that among patients on a strict GFD, 38% of biopsied patients still had intestinal damage.⁵ An analysis of data from a large registry of patients diagnosed with celiac disease revealed that 47% reported symptoms even with adherence to a strict GFD.⁶ More common than celiac disease, non-celiac gluten sensitivity (NCGS) is another condition involving an intolerance to gluten that improves on a GFD. NCGS is gaining attention among clinicians, but because there is no biomarker specific for NCGS, it is implicated when celiac disease, wheat allergy and other causes of symptoms have been ruled out.^2,4,7 In a survey of the general population, 13% of participants self-reported as sensitive to gluten.⁷

One of the main reasons for GFD non-compliance is that there are many sources for gluten contamination that may cause accidental gluten consumption. While CD patients may be able to tightly control and avoid consumption of gluten-containing foods in the kitchen at home or in restaurants that use only gluten-free labeled foods, it is nearly impossible to control products that are mislabeled as "gluten-free."⁸ There currently is no widely available method to accurately detect and measure the amount of gluten present in consumable products such as food, medication, and supplements, and many products labeled as gluten-free may in fact contain gluten in amounts that are sufficient to trigger symptoms and mucosal damage in CD patients.^9,10

While the intestinal biopsy is the "gold standard" for the detection of persistent mucosal damage, it would be more practical and cost-effective to be able to monitor patients for adherence to a GFD using non-invasive methods. However, currently utilized serological markers such as tTG IgA and EMA IgA are reported to have a sensitivity below 50% for the detection of persistent villous atrophy in patients on a GFD, and there is a need for a more accurate way of monitoring the non-response to a GFD.^5,11 The detection of gluten in stool samples is reported to be a reliable alternate approach to monitoring adherence to a GFD, thus allowing for the direct measurement of the disease-triggering source in these patients.¹¹ In a study of celiac patients on a GFD, among patients with persistent symptoms, 67% had detectable levels of gluten in their stools.¹¹ Gluten in stool remains detectable for up to four days after consumption.¹¹ In another study of patients endeavoring to adhere to a strict GFD, two-thirds were shown to have been exposed to gluten during the 10-day study period.¹²