Dust Mites and Eosinophilic Esophagitis

Given seasonal fluctuation in the activity of eosinophilic esophagitis (EoE), aeroallergens have been considered a trigger in some patients.

Briefly noted: A recent study (A Ravi et al. Gastroenterol 2019; 157: 255-6, editorial 17) showed that dust mite antigen was present in esophageal biopsy specimens at a greater level in adult patients with EoE compared to controls.  With active EoE, patients had dust mite staining in 1.6% of the field which was significantly greater than patients with inactive EoE (0.7). The control group had a complete absence of epithelial dust mite staining.

The editorial (Seena Aceves) notes that these investigators have also shown gluten accumulation in the EoE esophagus.  Whether dust mite antigens or other specific postulated aeroallergens plays a causative role is unclear.  This study shows the presence of these antigens in the esophagus but does not show whether this is an epiphenomenon due to increased permeability or whether these antigens activate the local immune system.

A second study (T Patton et al. JPGN 2019; 69: e43-e48) describes the outcome of coexisting celiac disease and eosinophilic esophagitis in 22 children (from a cohort of 350 children with celiac disease. 17 had repeat biopsies.  Four of 17 (23.5%) had resolution of EoE with a gluten-free diet.  Related blog post: Is there a Link Between Eosinophilic Esophagitis and Celiac Disease?

Sagrada Familia, Barcelona

Should Pediatric Patients with Celiac Disease Be Screened for Low Bone Mineral Density?

A recent retrospective study (J Webster et al. Clin Gastroenterol Hepatol 2019; 17: 1509-14) with 673 children with newly diagnosed (biopsy-proven) celiac disease (CD) (median age 10.6 y) evaluated DXA studies at time of diagnosis.

Key findings:

  • Approximately 7% (n=46) had a low lumbar spine areal bone mineral density (aBMD) z-score (less than -2)
  • Of those with abnormal aBMDs, 18 had repeat studies.  11 of 18 normalized after institution of dietary management. Mean time for repeat DXA was 2.3 years
  • Of note, mean BMI z-score at time of repeat DXA was 0.005 (this includes 90 who had followup studies after a normal baseline DXA).
  • Low body mass index (BMI) with z-score of -0.4 identified a >10% risk of an abnormal aBMD

The authors acknowledge than DXA screening is controversial.  The current study’s strength is its large size.  Limitations include the inability to correlate with clinical factors including adherence to a gluten-free diet.

My take:

  1. Based on this study, it is likely that only 2-3% of pediatric patients with celiac disease will have a persistently abnormal DXA after institution of a gluten free diet for 2 years; it is likely that even more will improve with time if receiving appropriate dietary treatment.
  2. I am not likely to recommend obtaining a baseline DXA study in pediatric patients with newly diagnosed celiac disease; the treatment for low bone mineral density in the setting of celiac disease is the same as for all children with celiac disease.  If one were inclined to look for low BMD, optimal timing would likely be AFTER being adherent on a gluten free diet for at least two years particularly in those who had low BMI at presentation.

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Columbus Monument, Barcelona

Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications/diets (along with potential adverse effects) should be confirmed by prescribing physician/nutritionist.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition

 

First Year of Life Antibiotics and Celiac Disease

Briefly noted:

A recent study (SD Sander et al. Gastroenterol 2019; 156: 2217-29) found an association between antibiotics in the first year of life and celiac disease.

The authors “collected medical information on 1.7 million children, including 3346 with a diagnosis of celiac disease” using nationwide register-based cohorts from Norway and Denmark.

Key finding:

  • “Exposure to systematic antibiotics in the first year of life was positively associated with diagnosed celiac disease,” pooled odds ratio 1.26.  Furthermore, there was a dose-dependent relationship with increasing number of exposures increasing the risk of celiac disease.

My take: The increase in prevalence of celiac disease over that past few decades is likely related to changes in our environment.  These changes affect nearly everyone, but some are more susceptible to immune-related disease that may be triggered by these environmental changes.  This study shows that early exposure to antibiotics is likely to be one of the environmental factors that increase the risk of celiac disease.

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Retiro Park, Glass Palace
Madrid

It Can’t Hurt Right? Complimentary and Alternative Medicine and Gluten-Related Disorders

A recent study (G Boyer et al. Am J Gastroenterol 2019; 114: 786-91) examined the promotion of testing and treatment of gluten-related disorders among complementary and alternative medicine (CAM) practitioners. Thanks to Ben Gold for this reference.

Background: CAM expenditures in 2016 by Americans was $30.2 billion in 2016. “Studies have found that it is not uncommon for CAM clinics to make wide-reaching claims as to their abilities to diagnose a plethora of conditions.”  In the present study, the authors reviewed the advertising content of 500 CAM clinic websites with regard to gluten-related disorders..

Key points:

  • The authors further identified 232 claims from 114 clinic websites; 138 (59.5%) were judged as unproven or false.
  • “Some clinics advertised treatments that pose potential harm;” this includes the sale of digestive enzymes promoted to digest gluten and which purport to allow the person with celiac or nonceliac gluten sensitivity (NCGS) to ingest gluten safely.  “This is a baseless claim that could lead to serious harm.”
  • “Other clinics falsely claimed that everyone should be on a gluten-free diet regardless of a diagnosis of celiac disease or NCGS.”

My take: Given the popularity of CAM along with the frequency of misleading claims, this suggests the need for increased regulation.  These websites are likely to increase confusion about the diagnosis and management of gluten-related disorders (which can  be confusing without any help!)

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AGA Practice Guidelines for Celiac Disease

AGA Clinical Practice Update on Diagnosis and Monitoring of Celiac Disease—Changing Utility of Serology and Histologic Measures: Expert Review (S Husby et al. Gastroenterol 2019; 156: 885-89)

Best Practice Advice 1: Serology is a crucial component of the detection and diagnosis of CD, particularly tissue transglutaminase–immunoglobulin A (TG2-IgA), IgA testing, and less frequently, endomysial IgA testing.

Best Practice Advice 2: Thorough histological analysis of duodenal biopsies with Marsh classification, counting of lymphocytes per high-power field, and morphometry is important for diagnosis as well as for differential diagnosis.

Best Practice Advice 2a: TG2-IgA, at high levels (> ×10 upper normal limit) is a reliable and accurate test for diagnosing active CD. When such a strongly positive TG2-IgA is combined with a positive endomysial antibody in a second blood sample, the positive predictive value for CD is virtually 100%. In adults, esophagogastroduodenoscopy (EGD) and duodenal biopsies may then be performed for purposes of differential diagnosis.

Best Practice Advice 3: IgA deficiency is an infrequent but important explanation for why patients with CD may be negative on IgA isotype testing despite strong suspicion. Measuring total IgA levels, IgG deamidated gliadin antibody tests, and TG2-IgG testing in that circumstance is recommended.

Best Practice Advice 4: IgG isotype testing for TG2 antibody is not specific in the absence of IgA deficiency.

Best Practice Advice 5: In patients found to have CD first by intestinal biopsies, celiac-specific serology should be undertaken as a confirmatory test before initiation of a gluten-free diet (GFD).

Best Practice Advice 6: In patients in whom CD is strongly suspected in the face of negative biopsies, TG2-IgA should still be performed and, if positive, repeat biopsies might be considered either at that time or sometime in the future.

Best Practice Advice 7: Reduction or avoidance of gluten before diagnostic testing is discouraged, as it may reduce the sensitivity of both serology and biopsy testing.

Best Practice Advice 8: When patients have already started on a GFD before diagnosis, we suggest that the patient go back on a normal diet with 3 slices of wheat bread daily preferably for 1 to 3 months before repeat determination of TG2-IgA.

Best Practice Advice 9: Determination of HLA-DQ2/DQ8 has a limited role in the diagnosis of CD. Its value is largely related to its negative predictive value to rule out CD in patients who are seronegative in the face of histologic changes, in patients who did not have serologic confirmation at the time of diagnosis, and in those patients with a historic diagnosis of CD; especially as very young children before the introduction of celiac-specific serology.

Management

Best Practice Advice 10: Celiac serology has a guarded role in the detection of continued intestinal injury, in particular as to sensitivity, as negative serology in a treated patient does not guarantee that the intestinal mucosa has healed. Persistently positive serology usually indicates ongoing intestinal damage and gluten exposure. Follow-up serology should be performed 6 and 12 months after diagnosis, and yearly thereafter.

Celiac Hepatopathy 2019

A recent retrospective study (E Benelli et al. JPGN 2019; 68: 547-51) examines a large cohort of patients (=700) who were diagnosed with celiac disease (CD) from 2010-2016 and had available liver transaminases.

Key findings:

  • ALT values >40 U/L were elevated in only 3.9% (27/700)
  • Younger age (<4.27 years) correlated with a higher risk of liver involvement with OR 3.73
  • Of these 27 patients with elevated ALT, 18 had adequate followup.  All but 3 patients normalized ALT values after at least 1 year; of these, 1 was diagnosed with sclerosing cholangitis. In the other two, one was thought to be nonadherent with gluten-free diet and one had dropped ALT to 47 U/L.
  • Thus, definitive autoimmune liver disease was identified in only one patient

My take: This study shows a lower rate of liver involvement than previous studies.

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Weak Link in Celiac Screening Guidelines

A recent study (AS Faye et al. Clin Gastroenterol Hepatol 2019; 17: 463-8) finds a weak link in the screening guidelines for celiac disease. Generally, guidelines recommend screening all symptomatic first degree relatives and consider screening of asymptomatic first-degree relatives.  Yet, little is known about adherence to these guidelines.

The authors utilized emergency contact information from the electronic records of 2081 patients with biospy-diagnosed celiac disease to assess how commonly celiac disease testing occurs in patients who are first-degree relatives.

Key findings:

  • Of the 539 relatives identified, 212 (39.3%) were tested for celiac disease including 193 of 383 (50.4%) of first-degree relatives and 118 of 165 (71.5%) of symptomatic first-degree relatives.
  • Of the 383 first-degree relatives, only 116 (30.3%) had a documented family history of celiac disease.

Thus, this study shows that ~30% of symptomatic first degree relatives have not received celiac testing and that ~70% of all first-degree relatives do not have a documented family history.

My take: If a family history of celiac disease is not conveyed to health care providers, this greatly reduces the likelihood that symptomatic first degree relatives will undergo recommended screening. This weakness in screening could be overcome by either:

  1. changing to a policy which encourages screening all first degree relatives, whether symptomatic or asymptomatic
  2. leveraging technology (when feasible) to assure that family history is documented in all at risk patients

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Shenandoah National Park