Today an article came out talking about large scale screening in children for Type 1 Diabetes and Celiac Disease. The study results showed a higher than expected positive rate for celiac disease screening. Screening and diagnosis are two different things – let’s discuss.
The ASK Study
There are two studies here to look at. The first is the Autoimmunity Screening for Kids or ASK study. This is the study where they took just under 24,000 children between 0 and 17 years of age. The scientists were looking for autoimmunity markers for celiac disease and type 1 diabetes.
They did three blood tests – “2 highly sensitive assays for tissue transglutaminase autoantibodies (TGA): a radiobinding (RBA) assay for IgA TGA and an electrochemiluminescence (ECL) assay that detects all TGA isotypes.” They are referring to the TGA tests as a combination of the TTG IGA and TTG IGG tests. They found that the ECL test was more sensitive than the other two and was able to detect celiac antibodies significantly earlier than the other two methods.
If they find that a child has an autoantibodies, the child is placed in a follow up group. Every six months tests are repeated. Tests can be confirmatory of earlier results or not.
In the conclusion the authors say two more really important things about celiac disease. First, they say, “we found the frequency of TGA for CD autoimmunity was significantly higher in children who were detected positive for islet autoantibodies of T1D autoimmunity.” This says that there is a higher rate of potential celiac disease in those with type 1 diabetes. This is a confirmatory statement to everything we already know about celiac disease and Type 1 diabetes.
Second the researchers say, “the study has a limitation of resources to provide complete clinical evaluation of intestinal biopsy for the confirmed positive cases whereas most of these children have been arranged for further clinical evaluation in their primary or outside care facilities.” In other words, they do not confirm the diagnosis of celiac disease in this study.
The second study
Out of the over 23,000 children in the ASK study, this study focuses on the first 9,900 children that completed the study. Scientists looked at the data and came to two conclusion.
The first conclusion based on their reading of the data is “initial results of this ongoing mass-screening program confirm a high prevalence of undiagnosed CD autoimmunity in a screened US population.” The second is “symptoms at initial screening were not associated with TGA status .” In this study, TGA status stands for tissue transglutaminase autoantibodies.
Okay – basically they are saying that symptoms are not a reliable indicator of active celiac disease. Duh.
Second, they found a higher than expected number of children that carry celiac antibodies. Often children with positive celiac antibodies had parents with celiac disease. But the researchers don’t mention whether the children were actually diagnosed with celiac disease or simply have potential celiac disease.
I’ve talked about the fault of celiac disease blood tests in children. A virus can cause blood tests to be inaccurate up to a year after being ill. We’ve also talked about a triple positive blood test diagnosis for children.
I’m concerned that this study correlates a positive celiac blood test with diagnosis. A single blood test at a single point in time is not enough to diagnose celiac disease.
Conclusion
Celiac is considered the most common autoimmune disease, but is underdiagnosed. Too many doctors brush off classic symptoms and provide a diagnosis like IBS. Even at that, symptoms don’t correlate to disease. So, you’ve got a double whammy here.
What really needs to happen is that doctors begin screening for celiac disease much earlier. Savvy pediatricians need to look for celiac disease is family members who may have other diseases with common genetic roots, like Type 1 Diabetes or Hashimoto’s Thyroiditis, as well as celiac disease. Changes in growth curves, constipation, and diarrhea need to be red flags for pediatricians to begin looking for a variety of diseases, including celiac disease.
In adults, screening for celiac disease should be as simple as adding the celiac panel to normal annual blood work if someone is at risk. If the blood tests indicate celiac might be present, then a referral to a gastroenterologist should happen.
The signs and symptoms of celiac disease are often subtle. Left untreated they are life threatening. Education for general practitioners regarding basics on reading celiac blood panels should be part of their ongoing education.
Maybe one of the big advocacy groups could get celiac disease screening added to the annual blood tests performed. Or at least run the celiac panel when vitamin B12 or vitamin D is low, or unexplained anemia is present. But something has to change.