Celiac disease and less diabetes?

While there is a well-recognized association between Celiac disease and insulin-dependent diabetes mellitus (IDDM), a recent study shows a lower prevalence of non-insulin dependent diabetes mellitus (NIDDM) and metabolic syndrome in patients with celiac disease (Gastroenterol 2013; 144: 912-17).

You-Tube Link: Patients With Celiac Disease Have a Lower Prevalence … – YouTube..Dr. Toufic A. Kabbani discusses his manuscript “Patients WithCeliac Disease Have a Lower Prevalence of Non-Insulin-Dependent Diabetes Mellitus and Metabolic Syndrome.”

A retrospective review of 840 patients with biopsy-confirmed celiac disease were compared with 840 random matched controls.  Controls were matched for age, sex, and ethnicity.  Mean age was 49.4 years.

Key findings:

  • 26 (3.1%) of celiac disease cohort and 81 (9.6%) (p <0.0001) had NIDDM.
  • 3.5% of celiac disease cohort and 12.7% of controls had metabolic syndrome.
  • Though celiac disease patients had lower BMI, these findings were still present after controlling for this variable.
  • Prevalence of NIDDM was strongly associated with age in both groups.  In celiac cohort, NIDDM occurred in 0% (n=343) of those <45, 3.1% in 45-64, and 9.3% in those >65.  In contrast, the control group had NIDDM in 3.5%, 11% and 19.3% respectively.

With regard to pathophysiology, the authors did not think the protection from NIDDM was related to malabsorption.  Evidence of malabsorption was more common in patients with CD and NIDDM than in those without NIDDM.

Related blog posts:

 

Nuance in Celiac Serology Interpretation

A recent study adds additional nuance to the interpretation of celiac serology (Clin Gastroenterol Hepatol 2013; 11: 398-403).

In this study the authors analyzed anti-TTG IgA levels from 104 consecutive pediatric and adult patients who were not IgA deficient.  The study took place between 2000-2009.  In addition, samples from 537 consecutive controls were available for comparison.

The study determined the likelihood of having celiac disease based on antibody level from four different companies and pre-test clinical factors.  The general population pretest probability was 1%; the pretest probability for their population was 6% if their were gastrointestinal complaints, 14% if weight loss/small stature was present, 11% for patients with anemia/iron deficiency, and 9% for patients with malabsorption.

Key findings:

Even in those with high antibody titers (>10-fold normal), if they were asymptomatic, only 53%-75% had celiac disease (depending on the individual assay).  That is, >10-fold elevation with some commercial assays did not correspond to >10-fold elevation in all of the assays leading to variable probabilities.

In patients with low level elevations (1-3 fold times the cut-off level), the probability of having celiac disease in asymptomatic individuals varied from 1% to 7%.  Thus, mild elevations in TTG IgA are not highly predictive in this asymptomatic population.  However, in those with pretest probability of 14%, the frequency of celiac disease varied among the four assays from 14% to 56%.

Take home message:  Not all assays for celiac disease are comparable.  While very high serology levels (>10 fold) are associated with celiac disease, in asymptomatic patients as few as 53% may have celiac disease.

Related blog links:

ADHD patients– not at increased risk for Celiac disease

It seems that so many conditions have been linked to Celiac disease; perhaps, Celiac disease is to health problems as Kevin Bacon is to actors (Six Degrees of Kevin Bacon – Wikipedia, the free encyclopedia).  A notable exception may be ADHD (JPGN 2013; 56: 211-14).

In a prospective study from Turkey, a total 362 children between 5 and 15 years who were diagnosed with ADHD at a child psychiatry clinic (2007-2010) were evaluated.  Serum levels of tissue transglutaminase (TTG) IgA and IgG antibodies were obtained; serum IgA levels were determined in those with isolated TTG IgG positivity.  In addition, the authors identified a matched control group of 390 children.

Results:

  • TTG IgA seropositivity was noted in 4 patients with ADHD (1.1%) compared with 3 controls (0.8%).  Only one of the four ADHD patients had histologic evidence of celiac disease (0.27%).
  • There was a higher incidence of TTG IgG in the ADHD group, 3.9% compared with 0.5% in controls. However, serum IgA was normal in all of these patients (indicating that TTG IgA was likely reliable).  Followup TTG IgG testing was negative consistent with false positivity.

Perhaps this result is not surprising to those who have seen a ‘classic’ celiac disease presentation.  In these children who often had physical signs of malnutrition including a bloated abdomen, the effect of a gluten-free diet changed a “perfectly-behaved” (=listless) child into a very active toddler.  So, in these children, a gluten-free diet but not celiac disease triggered hyperactivity.

Related blog posts:

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Expert review: Celiac disease

A recent article gives a concise expert update on Celiac disease (NEJM 2012; 367: 2419-26).

As this is an area that has been covered several times by this blog and is familiar to most of the followers, I will comment on a few issues that were particularly interesting to me.  Though, the review is thorough and a helpful reference on most aspects of celiac disease..

What is the gluten threshold?  In patients with celiac disease, a minimal degree of gluten contamination is difficult to avoid.  “The lowest amount of daily gluten that causes damage to the celiac intestinal mucosa over (the gluten threshold) is 10 to 50 mg per day (a 25-g slice of bread contains approximately 1.6 g of gluten).”  New regulations propose that foods which are labeled as gluten free have less than 20 ppm of gluten contamination.

When are intraepithelial lymphocytes increased in the duodenum?  The abnormal threshold is considered >25 per 100 enterocytes.

What proportion of celiac disease patients have been diagnosed?  According to a recent European study, only a small proportion (21%) of celiac patients are clinically recognized.

Best screening test currently? Anti-tissue transglutaminase (TTG) IgA antibody –both sensitivity and specificity are >95%.  Consider TTG IgG in patients with IgA deficieny or possibly deamidated gliadin IgG.

Potential complications of untreated celiac disease? Osteoporosis, impaired splenic function, neurologic disorders, infertility or recurrent abortion, ulcerative jejunoileitis, and cancer.

Biopsy needed? Usually, “although recent guidelines suggest that biopsy may not be necessary in selected children with strong clinical and serologic evidence of celiac disease.”

Population-based screening or case-finding?  At this time, population-based screening is not recommended.  Case-finding based on symptoms and screening of at-risk groups is recommended though this is likely to miss >50% of cases.

Related blog posts:

Is functional pain more common in children with Celiac disease?

A recent study adds information to the title question but does not resolve it (J Pediatr 2013; 162: 505-09).

The authors note that they expected to find a higher prevalence of abdominal pain and abdominal pain/functional gastrointestinal disorders among children with diagnosis of celiac disease.  They note that functional disorders have been more common after acute gastroenteritis and cow’s milk hypersensitivity of infancy presumably due to preceding inflammation.  Persistent low-grade intestinal inflammation and immune activation have been proposed as precipitating susceptibility to functional abdominal pain.

In this small retrospective study, a statistically significant difference in functional GI disorders was not observed.  Enrolled families were contacted by telephone at least 6 months after the diagnosis of Celiac disease.  They completed a telephone questionnaire and a separate Rome III questionnaire.

Celiac cases (n=49):  abdominal pain (24.5%), functional abdominal pain (4.8%), IBS (6.1%), dyspepsia (4.8%), abdominal migraine (4.8%), nonspecific abdominal pain (6.1%)

Control cases (n=48): abdominal pain (14.6%), functional abdominal pain (6.3%), IBS (2.1%), nonspecific abdominal pain (6.1%)

Given the question that the authors were trying to answer, this study was unlikely to be helpful.  Problems with the study:

  • The biggest problem is the small number of patients.
  • Cross-sectional design
  • Reliance of recall symptoms
  • Lack of information on dietary adherence
  • Collection of information from only parents contributed

Bottomline: While screening for celiac disease is common in patients with possible functional abdominal pain, treatment with a gluten-free diet may not resolve these symptoms. Functional abdominal pain is at least as common in children with celiac disease as in the general population.

Related blog post:

Shout out for Gluten-Free Camp

One enjoyable aspect about my work with my colleagues has been their willingness to use their free time to participate and develop programs for children.  For many years, this has included several camps at Camp Twin Lakes, particularly Camp Oasis for children with inflammatory bowel disease. Most of the physicians in our group have given their time to support this camp.  In recent years, Larry Saripkin has spent a week there every summer  and Stan Cohen really established this camp in Atlanta.  In addition, our nurses have volunteered their time as well; they stay busy attending to the medical needs of these kids so they can enjoy a camp experience.

More recently, a camp for kids with celiac disease has been started, Camp WeeKanEatIt.   Under Jeff Lewis’ direction and fundraising, this camp has been started and allows kids  (8-17 yrs) who need to be maintained on a gluten-free diet to experience camp.  Siblings are allowed to attend as well.  Don’t forget this year’s camp dates: June 23-28!

Related links:

Duodenal IELs and the likelihood of celiac disease

The diagnosis of celiac disease has definitely become more complex due to the interplay of serology, genetic markers, clinical response to gluten-free diets, and histology.  The Mayo clinic pediatric experience with duodenal intraepithelial lymphocytosis (IELs) with normal villous architecture highlights this issue (JPGN 2013; 56: 51-55).

Between 2000-2009, 56 children from the Mayo clinic pathology database of duodenal biopsies (n=1290) were identified.  Among this group, 48 had serological testing for celiac disease (CD).  Ultimately, 9 were labeled with CD, though only 5 met the ‘definite’ criteria.  Other conditions that were associated with increased IELs included the following:

  • Medication exposure
  • Inflammatory bowel disease
  • H pylori infection
  • Autoimmune conditions
  • IgA deficiency

So, which patients with duodenal IELs had CD?

  • “Definite” CD was used to define patients with elevations in two different serologic markers (TTG and EMA) or those with elevation in one serologic marker along with a documented clinical response to a gluten-free diet (GFD).
  • “Possible” CD described patients with normal serology, but serologic titer and clinical response was noted on a GFD.
  • “Unlikely” CD categorized patients with two negative serology markers who had compatible human leukocyte antigen haplotype and had clinical response to GFD.

In addition, if the IELs were predominantly on the villi tips, this increased the likelihood of CD.

Related blog posts:

False-positive serology for Celiac disease

It is prudent to exercise caution in establishing a diagnosis of Celiac disease (CD) in young asymptomatic children who are identified with screening serology (J Pediatr 2012; 161: 980-14).

In this Italian study, a nationwide, multicenter, prospective intervention trial was established to assess the role of age at gluten introduction on development of CD.  Subjects were recruited at birth who were at increased risk for CD; they had at least one first-degree relative with CD.

In their cohort, 96 children were identified.  In addition to having an affected first-degree relative, all children had positive serology (21 with positive tissue transglutaminase IgA antibody [tTG] and 1 with IgA deficiency/positive gliadin IgG antibody) and results of a small intestinal antibody.

While 72 had definitive CD, 24 were considered potential CD (serology positive/Marsh 0-1 histology) and asymptomatic.  The fascinating part of this study was the followup of the potential CD cases –21/24 continued on a regular diet.  Only 1 developed overt CD. 18 (86%) developed normal serology and 2/21 had fluctuating antibody levels after two years.

Based on their findings as well as consensus guidelines, the authors propose that asymptomatic young patients with abnormal serology should be followed for at least 3-6 months as long as tTG < 11 times ULN.

Other findings:

  1. Breastfeeding may have a protective role; individuals with overt CD had a shorter mean duration of breastfeeding than the potential CD group (4.2 months compared with 5.1 months).
  2. Gluten introduction at age 6 months did not increase risk of overt CD (compared to potential CD) relative to introduction at 12 months.

Related blog entries:

Closer followup for Celiac disease & pediatric guidelines

Data from the Mayo clinic indicate that Celiac patients are not followed up adequately (Clin Gastroenterol Hepatol 2012; 10: 893-99).

Data was extracted on 122 patients from Olmsted County.  Due to the Rochester Epidemiology Project, a comprehensive medical record is available for the entire county population (since 1966).

Results:

  • At 1 year following diagnosis, 41% of patients had followup visits; 89% within 5 years.
  • At followup visits, gluten-fee diet compliance was assessed in 33.6% and 79.8% respectively at 1 and 5 years.
  • The minority met with a dietician: 3.3% and 15.8% respectively at 1 and 5 years.
  • Serological followup was performed in 22.1% and 65.6% respectively at 1 and 5 years.

The related editorial (pages 900-901) makes the point that quality follow-up and outcomes would be aided by clear guidelines.  General guidelines in our practice are noted below.

When I review lists of patients with specific diagnoses, I am often surprised by the lack of follow-up for a number of conditions, not just celiac disease.  Developing a system to remind patients about follow-up for a wide range of conditions would be a worthwhile goal for pediatric practices.

Additional references/blog entries:

General Guidelines in our practice (developed by Dr. Jeff Lewis in 2009)
1. Who to test
There is a wide spectrum of clinical presentation from the classical malabsorption to a number of non-GI presentations.  Some studies suggest that the frequency of celiac in a peds GI clinic is as high as 1:40 (general population is 1:130).  Presentations that are common other than diarrhea, distention or FTT include constipation, anemia, abdominal pain, intussception, vomiting, short stature abnormal LFT’s, pancreatitis, and asymptomatic detection upon screening.  30% of newly diagnosed patients are overweight.  There is about a 5% risk in 1st and 2nd degree relatives, patients with type I DM, Down syndrome, and thyroiditis.  In 300 pediatric patients over 9 years, 10% presented with diarrhea, 20% abdominal pain, 23% as a result of screening, 5% with constipation, and 26% with growth issues.  Rates in family members include 1st degree relative 5 – 10%, MZ twins – 75% concordance rate, DZ twins – 10% concordance rate and HLA identical sibs – 30% concordance rate.

Recommend: Think about celiac disease with a variety of GI symptoms including those present in overweight patients.  Screen asymptomatic patients with Down’s, William’s syndrome, Type I DM, Thyroiditis, and in patients who are family members of celiac patients.

2. How to Test

Serology: Under age 3 years (some say 2 years) there is consensus that to consider including antigliadin IgA and AGA IgG along with anti-TTG and quantitative IgA.  Over age 3, anti-TTG and quantitative IgA should suffice but many are recommending also ordering EMA.  There is good evidence that anti-TTG assays vary from lab to lab.  There is also good evidence that anti-TTG in an individual may fluctuate over time.  Patients in the Teddy study (The Environmental Determinants of Diabetes in the Young (TEDDY …) have had abnormal anti-TTG followed by normal levels on the next blood draw.  17/82 had a positive anti-TTG convert to a negative on a regular diet and remain negative at all follow-ups.  For purposes of the Teddy study, two consecutive abnormal anti-TTG over 0.5 should be the threshold for EGD.  EGD after one abnormal TTG in the asymptomatic screened individual, may be too soon and lead to a false sense of security.  In a patient on a GF diet, testing serology may still be useful if the GF diet is less than 6 months.  HLA typing may help rule out celiac in patients on GF diet.

Gluten exposure prior to biopsy: There is no consensus on how long a patient needs to be back on gluten before testing but most experts suggest at least a month and some 2 or more months.

Biopsy is still considered essential in confirming the diagnosis.  Some studies suggest that some patients (2 to 3% of kids and perhaps adults) may show abnormalities in the bulb but not in the 2nd or 3rd portion of the duodenum.

Recommend:  anti-TTG and IgA will catch most patients with celiac.  Under age 3, consider obtaining AGA IgG and AGA IgA.  Addition of EMA may increase sensitivity of the anti-TTG.  Biopsy is still considered by celiac experts to be essential for the diagnosis.  At least 6 duodenal biopsies are recommended.  Some recommend 4 additional biopsies from the duodenal bulb. HLA testing has a role (mostly in excluding the possibility of celiac) though there are rare patients (about 1 in 100 celiac patients though some report much less) that are DQ2 and DQ8 negative.  Not all labs test for the beta chain and this can lead to a false negative HLA DQ2.

3. When might scoping not be necessary?

There is no expert consensus on this. If serology and symptoms are highly suggestive of celiac in a patient with a first degree relative with celiac disease, it is reasonable to make a diagnosis without endoscopic exam.  To confirm diagnosis, it is helpful to see the antibody levels fall on a GF diet (usually retest after 6 months).  Some studies have shown lower compliance rates in patients without biopsy proven celiac.

Recommend:  It is a personal MD:patient:parent decision as to diagnosing celiac without a scope.  If you do diagnose without biopsy, make sure that serology improves on a GF diet.  Celiac centers standard of care still includes biopsy all newly diagnosed patients.
4.Treatment once the diagnosis is made

NIH consensus conference on celiac recommends:1) treatment include referral to a trained dietician (Atlantametroceliacs.com lists nutritionists for adults)  2) availability of a community support group – georgiarock.org or email to celiacgroup@ccdhc.org 3) follow-up with an MD experienced with celiac. 3) lifelong adherence to gluten-free diet 4) identification and treatment of nutritional deficiencies 4) follow-up with an MD familiar with celiac ideally as part of a multidisciplinary team (primarily in partnership with nutritionist).

Recommend:  All newly diagnosed patients or those struggling with compliance should see a specially trained dietician.  You can also refer to the ROCK group – georgiarock.org or celiacgroup@ccdhc.org  You should see the patient in follow-up after diagnosis.
5. Follow-up

Follow up frequency varies widely from every 3 months after initial diagnosis with a nutritionist and an MD to lesser intervals.  Once well controlled, many experts recommend annual visits, some every 2 years.  At diagnosis it is often recommended to look for deficiencies in iron, folate, vitamin D and B12.  Patients are also at risk for other fat soluble vitamin deficiencies and zinc deficiency.  Bone mineral density is often performed one year after diagnosis with abnormalities referred to endocrinology – recommendations in pediatrics are still in debate.  As patients with celiac are at substantial risk for other autoimmune disorders, it is worth considering thryoid problems (eg. check TSH and free T4) early on after diagnosis and once every 1 to 2 years though this practice is of debatable cost effectiveness.  It can take up to a year for the anti-TTG to normalize but it should be coming down significantly in 6 months.

Recommend:  At time of diagnosis, usually a CBC should be obtained to allow you to look for clues about iron, folate, and B12.  It is not unreasonable to check 25 OH Vitamin D levels as well.  At least yearly follow-up labs should include an anti-TTG but may also include TSH, free T4, Vitamin D and a CBC.  Screening for folate, B12, and iron deficiency may also be considered.  Follow up closely after diagnosis can be helpful in dealing with the stress of a major life change and to ensure compliance and understanding of the disease.

6. Testing family members

It is clear that 1st and 2nd degree family members – with and without symptoms are at high risk.  Offering to screen siblings and parents once a diagnosis is made is reasonable due to risks associated with celiac disease.  If an at risk patient screens negative with serology, it does not mean that they can not get celiac disease in the future.  Some experts recommend retesting every few years or sooner if there are symptoms.  It is important to document that you recommended screening to 1st degree relatives.

Recommend:  Strongly recommend that symptomatic first degree relatives be screened for celiac disease.  It is reasonable and helpful to offer to do the screening of parents and siblings yourself.  There is good data that it is important to screen asymptomatic people at risk as there are increased risks in adults of developing cancers, auto-immune conditions, anemia, and osteoporosis in untreated celiac disease.  There are no good recommendations for retesting at risk individuals who initially test negative. HLA typing, if negative, can be useful in eliminating the need for routine rescreening.

7. Feeding infant siblings

A multicenter trial is underway to try to determine the best time to introduce gluten to genetically at risk individuals.  There is good evidence that breast-feeding can be protective.  There is good evidence that introducing small amounts of gluten while still breast-feeding may be protective.  There is good evidence that introduction of gluten before four months of age may increase the risk of developing celiac.  Some evidence exists that the best practice is to give a teaspoon of a gluten containing cereal a few time a week between 4 and 6 months of age (Scandinavian data and prospective data out of the Denver diabetes trial).  Fassano suggests that there may be benefit in keeping the infant gluten-free for the 1st year of life and introduce while still brest feeding after a year of age.  Final answer is still pending.  Gluten can be found intact in human breast milk but not cow’s milk.  No recommendations regarding mother’s diet while breastfeeding a patient with or at risk of getting celiac are available.

Recommend: Do not introduce gluten to at risk infants before 4 moths of age.  Support breast-feeding as something that may delay or even prevent the development of celiac disease.  There is some data to suggest that tolerance may be more likely of small amounts (1 tsp a day) of gluten containing food are introduced between 4 and 6 months of age.  During breast-feeding, a mother who does not have celiac may eat gluten during the pregnancy and throughout infancy.