My two-year-old son was diagnosed type 1 in January 2006 and started pumping in November. He had a blood draw (not fasting) last week for annual testing by our pediatric endocrinologist. While reviewing the results with the physician assistant, we found that the celiac screening had come back positive–Tissue Transglutaminase, IgA with a result of 18.8 with a laboratory standard of less than 7.0 as negative. She seemed surprised as my son has had no symptoms and is big for his age. We were given a referral for a gastrointestinal doctor they work with for more blood work.

After reading all the information on celiac and related testing I could find on this web site, I have a few questions. The first is about the accuracy of this screening test and the possibility or causes of a false positive. I am curious about the possibility of a false positive because the physician assistant said she has seen that before and pointed out that a few of the standard tests (platelets and lymphocytes) came back slightly high, indicating he had a mild virus at the time. I am also wondering about the range of the test. It tells me that above 7.0 is considered high, but not if that is mildly high or hugely high, I have no point of reference for how high the numbers might go.

My last question is really asking for your opinion(s). If the more conclusive blood tests still show a positive result, but he remains non-symptomatic, is growing well, and overall healthy, is the biopsy necessary? It seems like an invasive procedure for a little one who isn’t sick.

Asymptomatic celiac disease is rather common in type 1 diabetes, about 6 to 10% in our own experience and in many other centers as well. Certainly, it is important to confirm with repeat testing and also with other tests such as anti-gliadin antibodies, endomysial antibodies, as well as repeat transglutaminase antibodies. Each laboratory has different normative values and these need to be compared. We would also usually check for iron and ferritin levels, folic acid and B12 levels and watch, in older kids, for already pre-existing evidence, calcium and vitamin D malabsorption with abnormal bone density DXA scans. Adrenal and gastroparietal antibodies would also be checked, as would thyroid functions and thyroid antibodies since all of these are more commonly abnormal in type 1 diabetes, especially if there is a second autoimmune possibility.

Whether or not to do a biopsy is somewhat philosophical with most still suggesting that this be done as the most definitive evaluation. However, there are some researchers now saying that the antibody would be as good as or, perhaps, even better than the biopsy.

The reason for treating even an asymptomatic person with celiac is the potential for avoiding the long-term complications of celiac disease: growth failure or deceleration, delayed puberty, osteopenia and osteoporosis, other subtle vitamin and mineral deficiencies and bowel lymphomas/cancer. Exactly what the risk is when an otherwise asymptomatic child or adult is diagnosed and so treated remains unknown, but the risks in adults seems to be sufficiently high for me to recommend this approach to my patients/families. I would certainly encourage more testing and discussions as you are doing and then you can try to decide. The key question for me is this one: if I gave you a diagnosis with some increased chance of cancers and you could modify your food intake, even if burdensome, would you decrease your (unknown) risks by so doing? For me, the answer is a definite yes and for most of my patients/families, it is also yes. But now for everyone…

SB