Note: This is part 2 of several posts summarizing information discussed at the International Celiac Disease Symposium (ICDS) 2013 in Chicago 9/23-9/25.
The introductory lecture of the clinical forum of the International Celiac Disease Symposium (ICDS) 2013 in Chicago last week was entitled “Celiac Disease Today: An Overview” given by Drs. Alessio Fasano and Peter Green.
Although the official slides and presentations from the symposium are not yet available for purchase, based on my notes the following topics were addressed during this opening session:
Celiac Disease involves both an innate and an adaptive immune system response to gluten. 1 in 133 Americans have Celiac Disease. The risk of Celiac Disease in 1st degree relatives of Celiac patients (parents, siblings, and children) is 1 in 22. The risk in 2nd degree relatives (aunts and uncles and grandparents) is 1 in 39. Research has shown that the true prevalence of Celiac Disease has increased by 15% in the last few decades. Most people with Celiac Disease (83%) are unaware that they have it…
Although the current “gold standard” for diagnosing Celiac Disease is to perform an endoscopy and small intestinal biopsy, Dr. Fasano did bring up the concept of the “4 out of 5” rule, in which some have proposed that Celiac Disease can be diagnosed if a patient meets at least 4 of the following 5 criteria:
- Adverse symptoms when gluten is ingested
- Elevated Celiac antibodies on serology (blood tests)
- An improvement in symptoms when gluten is removed from the diet
- Genetic markers (HLA DQ2 and/or 8, although he did mention that 1-2% of Celiacs are DQ2 and DQ8 negative)
- Abnormal small intestinal (duodenal) biopsy
Anti-TTG IgA antibodies are greater than 95% sensitive and 95% specific for Celiac Disease. The DGP IgA antibodies have a sensitivity and specificity of greater than 90%.
No one is born with Celiac Disease and it can develop at any age. Celiac Disease involves a shift from gluten tolerance to an immune (autoimmune) response to gluten. The current thinking is that in order to develop Celiac Disease, one must have a genetic predisposition, ingest gluten, and be exposed to a (yet to be defined) environmental factor. In order to figure out exactly what the environmental factor(s) are, researchers will need to follow a large cohort of children from birth and monitor them for the development of Celiac Disease. We did learn later during the conference that this is actually being done as part of the “Prevent Celiac Disease Study” in Europe, which I will discuss in a later post (www.preventCD.com).
It is now believed that a change in the gut microbiome (bacteria) is involved in the pathogenesis and development of Celiac Disease. Although our gut microbiomes are inherited from our mothers, the composition of our gut bacteria is continually changing. There has been some recent research showing that birth by c-section increases a child’s risk of Celiac Disease by 2-3x. During a normal vaginal delivery newborns’ digestive tracts are colonized by bacteria that they pick up from their mothers’ bodies during labor and delivery. During a c-section this mother to infant transfer of bacteria does not take place.
There are over 70 clinical trials of Celiac Disease going on right now, many of which are currently enrolling subjects. You can check out www.clinicaltrials.gov and search for “celiac disease” for more information.
Dr. Green stated that currently recognized gluten related disorders include Celiac Disease, gluten ataxia, dermatitis herpetiformis, wheat allergy, and non celiac gluten sensitivity (NCGS). NCGS was discussed at the ICDS pre-conference (see my previous post for more details). Celiac Disease can be differentiated from these disorders by the presence of intestinal inflammation and villous atrophy. Based on a 2012 publication, only 17% of people with Celiac Disease have actually been diagnosed. Young men in the age range of 20-30 have the lowest rates of diagnosis.
Currently recognized risk factors for Celiac Disease include formula feeding, being introduced to gluten before 4 months of life or after 7 months of life, being born during the winter months, PPI (proton pump inhibitor, a type a reflux medication) use, and frequent respiratory infections during infancy. Much of this information comes from Sweden, where there was an epidemic of Celiac Disease in children during the 1980s and 1990s which triggered much research and analysis.
We were cautioned of a few pitfalls in the diagnosis of Celiac Disease, many of which I will describe in more detail in future posts. Some of the researchers have found that TTG (tissue transglutaminase) antibody testing from certain labs can be unreliable. Likewise, some research has shown that only 35% of the biopsies performed during evaluations for Celiac Disease are done correctly. Most GI docs take only 2 samples of small bowel, despite the current recommendations that 4-6 samples be taken.
Although Celiac Disease is often associated with digestive symptoms, many patients do not have any symptoms at all (i.e. they are picked up because they are screened due to having a family member with Celiac). Some of the most severe cases of Celiac Disease have been found in patients whose only symptom is anemia (low red blood cell count). On the flip side, a 2009 study showed that only 51% of patients with symptoms of Celiac Disease were actually screened.
A few sort of depressing stats:
-only 20% of patients with Celiac Disease have adequate follow-up after diagnosis
-the average U.S. medical student learns about Celiac Disease for one hour during medical school (I can personally relate to this one!)
And things that I think everyone should know:
-If a patient has dermatitis herpertiformis (DH), then they have Celiac Disease. Dr. Green stated that if one has DH, there is no need for a small bowel biopsy.
-1st degree family members of Celiac Disease patients should be screened every 5 years.
-The Celiac Center at Beth Israel Deaconess Medical Center in Boston has a great new website called “Celiac Now.” Check it out here.
More ICDS information to come soon…Also, any questions are welcome in the meantime!