Food-Specific IgG4: With This Guided Testing, You Can Achieve the Same Results As Those Who Don’t Have This Testing

On first glance at this article, it looks like the authors have found that testing for food-specific IgG4 (FS-IgG4) could be useful in guiding dietary treatment for eosinophilic esophagitis (EoE). However, the data don’t support this conclusion.

Methods: Prospective observational cohort in adult patients with EoE (n=22 along with 13 controls) placed on elimination diet based on FS-IgG4 levels (ImmunoCAP, cutoff of 10 mgA/L).

Key findings:

  • Elevated serum FS-IgG4 to 1 or more food groups (median 2) was identified in 21/22 (95.4%) patients with EoE; 20/21 underwent 6-week dietary elimination
  • Nine (45%) patients had histological remission (<15 eosinophils per high-power field)
  • Serum FS-IgG4 did not decline by 6-week follow-up. In addition, there was no difference in the FS-IgG4 levels between active and inactive EoE
  • 19 of 22 (86.4%) patients had high FS-IgG4 to milk and 13 of 22 (59.1%) had high FS-IgG4 to wheat. No patients required seafood elimination

The authors note in their introduction that total IgG4 levels in the esophagus are 45-fold those of healthy controls. In addition, “a preliminary study assessing trigger foods in patients undergoing 6FEDs has demonstrated elevated FS-IgG4 was associated with trigger foods in esophageal secretions but not foods that did not trigger esophageal eosinophilia” (K Peterson et al. Aliment Pharmacol Ther 2020; 52: 997-1007).

Despite the lack of any proven efficacy of this FS-IgG4-directed diet (over empiric elimination), the editorial suggests that FS-IgG4 levels may be beneficial, noting that the histologic remission rate increased to 64.3% after excluding ~30% patients with concerns of non-adherence. Removing 30% of patients to get better results would often be called “cherry-picking.”

In addition, neither the editorial (nor the study) delves into the fairly high rates of FS-IgG4 to milk and wheat. This suggests that FS-IgG4 testing will be unreliable with numerous false-positives (though there is wide range of reported reactions to milk and wheat in the literature). Even the control group had high FS-IgG4 to milk in half of the patients. Both the editorial and the study review the limitations which include small sample size, need for control group with atopy, and a lack of established cutoff values for FS-IgG4.

My take: This is a NEGATIVE study. Using FS-IgG4 levels to guide elimination diet was NOT better than empiric elimination of either 1 or 2-food groups. This finding should be more clearly stated in both the study and the editorial. It would be very useful to provide specific dietary advice to our patients with EoE. It is possible that a larger study with higher cutoff levels could find some utility for FS-IgG4. However, this study does not make this approach look terribly promising.

Related blog posts.

Arches National Park

Dupilumab (Dupixent) for Young Children with Eosinophilic Esophagitis (Published Data)

M Chehade et al. NEJM 2024;390:2239-2251 Dupilumab for Eosinophilic Esophagitis in Patients 1 to 11 Years of Age

This study provides published data that has been referenced previously at time of FDA approval and prior meetings (see posts: Dupixent Approved in Younger Children (15 kg+), Dupixent for Eosinophilic Esophagitis (1-11 yrs) and Clinical Diagnosis of Rumination from DDW Tweets).

Methods:

  • Part A -In this phase 3 trial, we randomly assigned, in a 2:2:1:1 ratio, patients 1 to 11 years of age (n=102) with active eosinophilic esophagitis who had had no response to proton-pump inhibitors to 16 weeks of a higher-exposure or lower-exposure subcutaneous dupilumab regimen or to placebo (two groups)
  • Part B- At the end of Part A, eligible patients in each dupilumab group continued the same regimen and those in the placebo groups were assigned to higher-exposure or lower-exposure dupilumab for 36 weeks  

Key findings:

  • In Part A, histologic remission occurred in 25 of the 37 patients (68%) in the higher-exposure group, in 18 of the 31 patients (58%) in the lower-exposure group, and in 1 of the 34 patients (3%) in the placebo group
  • The higher-exposure dupilumab regimen led to significant improvements in histologic, endoscopic, and transcriptomic measures as compared with placebo
  • The improvements in histologic, endoscopic, and transcriptomic measures between baseline and week 52 in all the patients were generally similar to the improvements between baseline and week 16 in the patients who received dupilumab in Part A
  • Similar adverse effects were noted across all groups. There was an increased rate (at least 10%) of COVID infections in participants receiving dupilumab whereas the incidence of vomiting was at least 10 percentage points lower among patients who received dupilumab (either group) than among those who received placebo 

My take: Dupilumab is an effective option for eosinophilic esophagitis.

Related blog posts:

Manometry for Persistent Dysphagia in Eosinophilic Esophagitis

D Yogev et al. JPGN Reports; 2024 https://doi.org/10.1002/jpr3.12083. Open Access! Manometric findings in children with eosinophilic esophagitis and persistent post-remission dysphagia

In this 10-year retrospective review (2013-2023), the authors reviewed children with EoE referred for high-resolution impedance manometry (HRIM) due to persistent dysphagia despite histologic healing (i.e., <15 Eos/hpf).

Key findings:

  • Among a cohort of ~1500 children, only 4 patients met inclusion criteria:  histologic remission (<15 eos/hpf) and absence of fibrostenotic features on endoscopic evaluation
  • Thus, the estimated prevalence of post-remission dysphagia in this cohort was exceedingly rare (<0.05%).
  • On HRIM, all four patients had a hypomotile esophagus and abnormal bolus clearance. Lower esophageal sphincter integrated relaxation pressure values were normal in three patients and elevated in one. Two patients were diagnosed with ineffective esophageal motility, one with aperistalsis and one with achalasia type 1.
Manometry findings from 12 yo diagnosed with Achalasia Type 1

Discussion:

  • “Endoscopic evaluation of fibrosis is somewhat limited as less than 50% of biopsies contain an adequate sample of the lamina propria for evaluation..[Also, these] patients did not undergo endoluminal functional lumen imaging (Endoflip) which has been recently shown to correlate with fibrotic changes of the esophagus in pediatric patients…Nonetheless, this case series highlights the fact that esophageal dysmotility can persist, even in the absence of endoscopic or histologic findings”
  • The authors “did not study all EoE patients treated in our facility who had persistent dysphagia despite histologic remission of EoE, but rather explored just those who were referred for manometry. This methodology creates a risk of referral bias.”

My take: Though there is a referral bias due to the methodology, this study suggests that persistent dysphagia is rare in children who achieve EoE histologic remission. In addition, in those with significant dysphagia despite improvement in EoE, manometry is worthwhile.

A related study suggests that achalasia may be more common in patients with Klinefelter syndrome, though still quite rare: L Miller et al. JPGN Reports 2024: https://doi.org/10.1002/jpr3.12084 Open Access! Achalasia in Klinefelter syndrome: A suspected pediatric case as well as prevalence analysis suggesting increased risk in this population

Related blog posts:

Budesonide FDA-Approved for Eosinophilic Esophagitis

AAP News 2/13/24: FDA approves first oral therapy for EoE

Eohilia is given in doses of 2 milligrams twice a day for 12 weeks. The label notes it has not been shown to be safe and effective for longer.

The FDA accepted Takeda’s new drug application in December 2020. A year later, the FDA determined more study was needed. Takeda revised its application and resubmitted it in September 2023.

Takeda conducted two multicenter, randomized, placebo-controlled trials in patients 11 to 56 years and 11 to 42 years, respectively. The first found 53% of the treatment group achieved histologic remission compared to 1% receiving a placebo. The second found 38% of the treatment group achieved remission vs. 2% of the placebo group, according to Takeda…

Patients [need] to refrain from eating or drinking for at least 30 minutes after taking Eohilia. After 30 minutes, patients should rinse their mouth and spit to reduce the risk of developing thrush.

My take: Budesonide has been used effectively for EoE for a long time; it is good news that it is recognized by FDA with a specific EoE indication. However, it is a little concerning that the label indication is for 12 weeks when we know that this is chronic disease. Also, I am eager to see how much this formulation costs in comparison to the budesonide ampules.

Related blog posts:

NASPGHAN Alert: Flovent HFA Discontinuation

12/7/23 NASPGHAN Alert: Guidance for Flovent HFA Upcoming Discontinuation Used For The Treatment of Eosinophilic Esophagitis

Situation:
Brand name Flovent HFA will no longer be manufactured after December 31, 2023.

Background:
• Flovent HFA is a commonly utilized swallowed topical steroid treatment for patients with eosinophilic esophagitis (EoE). It works by the patient swallowing the aerosolized medication dispensed by a metered dose inhaler (MDI).
• Both Medicaid and many private insurance formularies have transitioned to breath-actuated inhalers as their preferred inhaled steroid formulation, which cannot be used for EoE because they cannot be swallowed.
• GlaxoSmithKline will be discontinuing manufacture of brand Flovent HFA after December 31, 2023. While an authorized generic fluticasone HFA is available, it is not listed on many insurance formularies and for those that do include it, it is typically not listed as a preferred medication.
• Two other steroid MDIs are available on the market – Alvesco HFA (ciclesonide) and Asmanex HFA (mometasone). Limited data is available regarding dosing and efficacy in EoE 1,2.
• We are actively working to raise these concerns with major payors.

Assessment & Recommendation:
Given upcoming Flovent HFA discontinuation, patients needing this formulation of drug could be switched to generic fluticasone HFA. For many insurances this may require a prior authorization, which may delay initiation of the medication and families should be counselled accordingly.

In those whom generic fluticasone HFA is denied despite submission of a prior authorization, alternative options include:
• Oral viscous budesonide
• Swallowed topical Asmanex (mometasone) HFA or Alvesco (ciclesonide) HFA. Data on dosing in EoE is limited and these medications are also likely to require a PA.

References:
1. Tytor J, Larsson H, Bove M, Johansson L, Bergquist H. Topically applied mometasone furoate improves dysphagia in adult eosinophilic esophagitis – results from a double-blind, randomized, placebo-controlled trial. Scand J Gastroenterol. 2021 Jun;56(6):629-634. doi: 10.1080/00365521.2021.1906314. Epub 2021 Apr 8. PMID: 33831327.
2. Nistel M, Nguyen N, Atkins D, Miyazawa H, Burger C, Furuta GT, Menard-Katcher C. Ciclesonide Impacts Clinicopathological Features of Eosinophilic Esophagitis. J Allergy Clin Immunol Pract. 2021 Nov;9(11):4069-4074. doi: 10.1016/j.jaip.2021.06.058. Epub 2021 Jul 19. PMID: 34293498.

The information provided is intended solely for educational purposes and not as medical advice. It is not a substitute for care by a trained medical provider. NASPGHAN does not endorse any of these products and is not responsible for any omissions. For additional information please email floventquestions@naspghan.org.

Any substitution should only be done under the recommendation and supervision of a healthcare professional. 

Practical Guide to Dietary Therapy for Eosinophilic Esophagitis

JW Chang et al. Clin Gastroenterol Hepatol 2023; 21: 1690-1698. Open access! Development of a Practical Guide to Implement and Monitor Diet Therapy for Eosinophilic Esophagitis

  • The authors note that dietary therapy is underutilized–“successful clinical implementation is hampered by the need for a multidisciplinary approach including dietitian support and provider expertise.”
  • “Because symptoms are often discordant with underlying disease activity, symptoms alone should not be used to make decisions about treatment changes.56 Relying on symptoms in isolation to guide food elimination or reintroduction is insufficient and can result in false identification of food triggers and unnecessarily prolonged dietary restriction. Patients should be warned that their trigger foods are not necessarily the foods that cause immediate symptoms related to obstruction (eg, commonly meats, bread, sticky textures). Endoscopy with biopsy is the gold standard for monitoring response to therapy and is recommended at least 6–8 weeks after a change in therapy, including elimination and reintroduction phases to identify of food triggers.57“
  • “The most identified food triggers for EoE are animal milk (up to 90%) and wheat (up to 75%), and up to half of patients who undergo dietary therapy will have more than 1 dietary trigger. 58,62 In a recent study of adult patients undergoing dietary therapy with the SFED, 69% of patients had only 1 food trigger identified, making this a reasonable option for long-term therapy.59“
  • “The most common reasons for nonresponse to the elimination phase include purposeful or inadvertent dietary nonadherence, cross-contamination, and incorrect or inadequate removal of potential food triggers”
  • While medications used for EoE treatment are expensive, repeated endoscopy for dietary therapy may be costly and is an important consideration
  • The Consortium of Eosinophilic Gastrointestinal Disease Researchers (CEGIR) 58 page Supplement in article: Resource Supplement for Dietary Management for Patients/families -includes guidance for selecting food, apps, websites
Step-up strategy: 1 food dairy, 2 foods dairy/wheat, 4 foods dairy/wheat/soy/eggs, 6 foods dairy/wheat/soy/eggs/fish/peanuts

Related blog posts:

Managing Adrenal Insufficiency in Eosinophilic Esophagitis

M Nistel et al. JGPN 2023; 76: 786-792. Impact of Dose Reduction of Topical Steroids to Manage Adrenal Insufficiency in Pediatric Eosinophilic Esophagitis

In this retrospective study with 32 children with both eosiniphilic esophagitis and adrenal insufficiency (and 81 control subjects), key findings:

  • There was no steroid threshold which corresponded to an increased likelihood of AI
  • 20 of 32 had resolution of AI: 30% discontinued topical steroids, 50% reduced the steroid dose, 20% discontinue ER budesonide. With larger steroid dose reduction, there was an increased likelihood of AI resolution

One of the more useful parts of this publication is the authors provided their standardized approach in identifying AI: “our standard practice is to obtain a morning cortisol level 4-6 months after initiation of STS [swallowed topical steroids]. Subjects with morning cortisol <5 mcg/dL on 2 occasions (due to concerns with assay variation, patient compliance with fasting and holding steroids prior to testing) are then referred to endocrinology for further evaluation.”

My take: This article lays out a good approach for identifying AI in kids with EoE and then provides data on how effective reducing steroids are in resolving AI. It is noted that the peak eosinophil count tended to increase when STS doses were decreased.

Related posts:

Unrelated article from NPR (not from The Onion): Harvard professor who studies dishonesty is accused of falsifying data (June 26, 2023)

Lego turtle above and polar bear below at Tucson Botanical Gardens

Updated Nomenclature for Eosinophilic Gastrointestinal Diseases

ES Dellon et al. Clin Gastroenterol Hepatol 2022; 20: 2474-2484. Open Access! International Consensus Recommendations for Eosinophilic Gastrointestinal Disease Nomenclature

This article has 91 authors! Using Delphi surveys, the authors recommend the following:

  • “EGID” was the preferred umbrella term for disorders of gastrointestinal (GI) tract eosinophilic inflammation in the absence of secondary causes
  • Involved GI tract segments will be named specifically and use an “Eo” abbreviation convention: eosinophilic gastritis (now abbreviated EoG), eosinophilic enteritis (EoN), and eosinophilic colitis (EoC)
  • For EoN, “it is desirable, but not required, to name specific locations of small bowel involvement, if these are known…The abbreviation for eosinophilic duodenitis should be “EoD”… for eosinophilic jejunitis should be “EoJ”….eosinophilic ileitis should be “EoI”
  • The term “eosinophilic gastroenteritis” is no longer preferred as the overall name (but can be used to indicate involvement of both the stomach and small bowel)
  • When >2 GI tract areas are involved, the name should reflect all of the involved areas

I-SEE for Eosinophilic Esophagitis

ES Dellon et al Gastroenterol 2022; DOI: https://doi.org/10.1053/j.gastro.2022.03.025 Open Access: A Clinical Severity Index for Eosinophilic Esophagitis: Development, Consensus, and Future Directions “The Index of Severity for Eosinophilic Esophagitis (I-SEE)—that can be completed at routine clinic visits to assess disease severity using a point scale of 0–6 for mild, 7–14 for moderate, and ≥15 for severe EoE.”

From AGA: Eosinophilic Esophagitis Index

“The Index of Severity for EoE (I-SEE) is now available for you to use as a tool to help assess EoE patients. Developed by a multidisciplinary team of experts, the new tool is now published in Gastroenterology.”

Details about I-SEE 

  • “The I-SEE has three domains: (1) symptoms and complications, (2) inflammatory features and (3) fibrostenotic.
  • I-SEE can be used at initial diagnosis and then at each subsequent visit, with the recall being only between visits so that the severity can be assessed over time and ultimately (when data supports this step) treatment and monitoring adjusted based on severity.
  • As the number of children and adults with EoE increases worldwide, a simple system to assess and track disease activity in a meaningful way in a clinical setting is needed.
  • I-SEE is for use in adult and pediatric patients with EoE. It was created by an international team of more than 30 experts in allergy, gastroenterology and pathology.”

Link: I-SEE Tool Scoring Table