The Celiac Iceberg Revisited At Icds 2013
Posted by jebby, 26 October 2013 · 994 views
The second to last session on day one of the 2013 International Celiac Disease Symposium (ICDS) was a talk entitled, “Melting the Celiac Iceberg-potential, latent, silent: to treat or not to treat?” I was very confused about these terms when I first came across them in the Celiac medical and research literature a few years ago.
“Silent” Celiac Disease refers to patients who have Celiac Disease (elevated Celiac antibodies on blood testing and abnormal small bowel mucosa on endoscopy and biopsy) but no outward symptoms (or at least, do not appreciate any abnormal symptoms). Many silent Celiacs are picked up when they are screened for Celiac Disease due to having a family member with Celiac Disease and/or being in a high risk category for Celiac Disease, i.e. having Type 1 Diabetes.
“Latent” or “Potential” Celiac Disease is the term for when a patient has abnormally high Celiac antibodies on blood testing but either normal, or almost normal, small bowel mucosa on endoscopy. Many with potential Celiac Disease have abnormal symptoms. Some patients with this problem are told they are gluten sensitive, some have been told that they may have “early” or “pre” Celiac Disease, some are told by their doctors that they can continue to eat gluten, and others are advised by their doctors to go gluten free. My understanding is that, in recent years, the word “potential” is preferred over the word “latent” to describe this group.
Dr. Daniel Leffler, from the Celiac Center at Beth Israel Deaconess in Boston, presented the case for the gluten-free diet in patients with potential and silent Celiac Disease, while Dr. Riccardo Troncone, from Naples, Italy, presented the case against the gluten-free diet in these populations. Here are some interesting points that were brought up during both sides of the debate:
Children with first-degree relatives with Celiac Disease (parents and/or siblings) should be screened for Celiac Disease every 2-3 years in the absence of outward symptoms. Many “silent” Celiacs who think they feel “fine” prior to diagnosis will notice improvement on the gluten-free diet. The presenters reminded us that 60% of newly diagnosed Celiacs have atypical symptoms.
There are many types of tissue transglutaminase (TTG) antibodies. Type 2 TTG antibodies can attack the placentas of pregnant women, type 3 cause the skin problem of dermatitis herpetiformis, and type 6 can attack the brain and nervous system. As an aside (from another talk during the ICDS), the commercially available assays in the U.S. test for Type 2 only!
There is conflicting information of the risks to silent Celiacs who do not go gluten free. One study in 2006 (Metzger, et al.) showed that untreated silent Celiacs have an increased risk of mortality and cancer over a 10 year period. But another study in 2009 (Lohi, et al) did not show an increase in cancer for this group. As with many areas, more research is necessary.
According to Dr. Troncone, it is not known if untreated silent Celiac Disease is associated with the development of other autoimmune diseases. He did state that going gluten-free does not improve blood glucose control in patients who have both silent Celiac Disease and Type 1 diabetes.
Dr. Leffler presented research that shows that up to 50% of potential Celiacs will develop full blown Celiac Disease over a 5 year period and reminded us that TTG antibodies can cause harm even if there are no intestinal changes. He also stated that in order to be diagnosed with “potential” Celiac Disease that one must have an abnormally high TTG antibody level on at least 2 separate occasions (this is to rule out a false positive on the initial test).
I felt that the take home message from this lecture/debate was that those with silent and potential Celiac Disease should be on the gluten-free diet, but that much more research is needed. Per my notes, they recommended that silent Celiacs should be gluten-free, but it was not explicitly stated that potential Celiacs need to be gluten-free. My concern is that many potential Celiacs may actually have full blown Celiac Disease that was not picked up on biopsy (it was emphasized throughout the conference that many biopsies are not done correctly and that too few samples are taken). I will update all of my ICDS posts once I can get my hands on the power point presentations from the lectures, which I hope is soon! We were unable to take photos of the slides and although I tried to write as quickly as I could, I will add in key information that I may have missed.