HOW TO
DETECT EG/EoD

Diagnosis of eosinophilic gastritis and/or eosinophilic duodenitis (EG/EoD) can be STRAIGHTFORWARD WITH SYSTEMATIC COLLECTION OF BIOPSIES AND COUNTING OF MUCOSAL EOSINOPHILS1-4

DIAGNOSTIC PROTOCOLa,b

  • Abbreviations: EGD, esophagogastroduodenoscopy; GI, gastrointestinal; hpf, high-power field.
  • a Allakos does not provide medical advice and assumes no liability for medical care decisions made using this approach. Medical care decisions for individual patients are to be made by patients’ healthcare professionals, including decisions regarding diagnosing EG/EoD and how to evaluate biopsy samples.
  • b Diagnostic algorithm based on recommendation of experts involved in prospective clinical studies of EG/EoD.
  • c In 5 hpfs in the stomach and/or 3 hpfs in the duodenum.3,7,8
  • d In the absence of other causes of eosinophilia (eg, infection).1

A diagnosis of EG/EoD can be easily missed without systematic biopsy and histopathology protocols6

The approach used in recent EG/EoD studies included the following steps:

  • Take biopsies even if visually normal, as mucosae appear normal endoscopically in about half of all cases8
  • During EGD, take at least 8 biopsies from the stomach and 4 from the duodenum, as eosinophilic inflammation is very patchy and can affect one or both regions3,6
  • Request that your pathologist report gastric and/or duodenal eosinophil counts if ≥30/hpf, the accepted threshold for diagnosis of EG/EoD1-3

A diagnosis of EG/EoD can be easily missed without systematic biopsy and histopathology protocols6

The approach used in recent EG/EoD studies included the following steps:

  • Take biopsies even if visually normal, as mucosae appear normal endoscopically in about half of all cases9
  • During EGD, take at least 8 biopsies from the stomach and 4 from the duodenum, as eosinophilic inflammation is very patchy and can affect one or both regions4,6
  • Request that your pathologist report gastric and/or duodenal eosinophil counts if ≥30 per hpf, the accepted threshold for diagnosis of EG/EoD1,3,8
DOWNLOAD EG/EoD DIAGNOSTIC PROTOCOL

BIOPSY PROTOCOLa

Because eosinophil infiltration is patchy, multiple mucosal biopsies from different areas of the stomach and duodenum can optimize detection of EG/EoD1

A recent study indicated that symptom presentation in EG/EoD is similar regardless of the location of eosinophil infiltration, therefore it is important to systematically collect and evaluate biopsies from both the stomach and duodenum before ruling out EG/EoD10

a Allakos does not provide medical advice and assumes no liability for medical care decisions made using this approach. Medical care decisions for individual patients are to be made by patients’ healthcare professionals, including decisions regarding diagnosing EG/EoD and how to evaluate biopsy samples.
dBiopsy protocol based on recommendation of experts involved in prospective clinical studies of EG/EoD.4
e2-5 cm proximal to the pylorus.4

COLLABORATING WITH YOUR PATHOLOGISTa

Because diagnosing EG/EoD requires both a symptom assessment and histologic evaluation with tissue eosinophil counts, partnering with your pathologist can help patients receive an accurate diagnosis.

Systematic counting of eosinophils may not be routinely performed during histopathologic evaluation of gastric and duodenal biopsies and could lead to missed cases of EG/EoD.6

In your GI pathology requisition form, consider including information to help your pathologist know what to look for, such as:

  • Indicating that you suspect eosinophilic gastritis and/or eosinophilic duodenitis
  • Requesting that your pathologist count eosinophils per high-power field (hpf) in each biopsy sample
  • Requesting that your pathologist report if there are ≥30 eosinophils per hpf in any samplef
  • aAllakos does not provide medical advice and assumes no liability for medical care decisions made using this approach. Medical care decisions for individual patients are to be made by patients’ healthcare professionals, including decisions regarding diagnosing EG/EoD and how to evaluate biopsy samples.
  • fThe consensus threshold for diagnosis of EG/EoD is ≥30 eosinophils per hpf in 5 hpfs in the stomach and/or 3 hpfs in the duodenum in the absence of other causes of eosinophilia (eg, infection).1,3,7,8

Your pathologist may not be familiar with the method for evaluating for EG/EoD – download it here to share with them

DOWNLOAD HISTOPATHOLOGY METHOD

PHYSICIAN PERSPECTIVE:
DR EVAN DELLON OUTLINES A SYSTEMATIC APPROACH FOR DIAGNOSING EG/EoD USED IN RECENT EG/EoD STUDIES

Diagnosis of EG/EoD can be straightforward with systematic biopsy collection and close collaboration with your pathologist1,8

These healthcare professionals serve as disease education speakers for Allakos to help share EG/EoD insights like those in these videos, in addition to performing other services for the company. They receive compensation for this work.

Hear from leading gastroenterologist Evan Dellon, MD, MPH

THERAPIES THAT TARGET THE UNDERLYING CAUSE OF EG/EoD – EOSINOPHILS AND MAST CELLS – ARE URGENTLY NEEDED11,12

DIVE DEEPER

References: 1. Gonsalves N. Eosinophilic gastrointestinal disorders. Clin Rev Allergy Immunol. 2019;57(2):272-285. doi:10.1007/s12016-019-08732-1.  2. Egan M, Furuta GT. Eosinophilic gastrointestinal diseases beyond eosinophilic esophagitis. Ann Allergy Asthma Immunol.2018;121(2):162-167. doi:10.1016/j.anai.2018.06.013.  3. Dellon ES, Peterson KA, Murray JA, et al. Monoclonal antibody for eosinophilic gastritis and duodenitis. N Engl J Med. 2020;383(17):1624-1634. doi:10.1056/NEJMoa2012047.  4. Dellon ES, Peterson KA, Murray JA, et al. Monoclonal antibody for eosinophilic gastritis and duodenitis [supplemental appendix]. N Engl J Med. 2020;383(17):1-29. doi:10.1056/NEJMoa2012047.  5. Pesek RD, Reed CC, Muir AB, et al. Increasing rates of diagnosis, substantial co-occurrence, and variable treatment patterns of eosinophilic gastritis, gastroenteritis and colitis based on 10 year data across a multi-center consortium. Am J Gastroenterol.2019;114(6):984-994. doi:10.14309/ajg.0000000000000228.  6. Chehade M, Kamboj AP, Atkins D, Gehman LT. Diagnostic delay in patients with eosinophilic gastritis and/or duodenitis: a population-based study. J Allergy Clin Immunol Pract. 2021;9(5):2050-2059.e20. doi:10.1016/j.jaip.2020.12.054.  7. Talley NJ, Kamboj AP, Chey WD, et al. Endoscopy and systematic biopsy of patients with chronic gastrointestinal symptoms leads to high discovery rate of patients who meet histologic criteria for eosinophilic gastritis and/or eosinophilic duodenitis. Abstract presented at: Digestive Disease Week Virtual; May 22, 2021.  8. Dellon ES, Gonsalves N, Rothenberg ME, et al. Determination of biopsy yield that optimally detects eosinophilic gastritis and/or duodenitis in a randomized trial. Clin Gastroenterol Hepatol. 2021;S1542-3565(21)00592-9. doi:10.1016/j.cgh.2021.05.053.  9. Reed C, Woosley JT, Dellon ES. Clinical characteristics, treatment outcomes, and resource utilization in children and adults with eosinophilic gastroenteritis. Dig Liver Dis. 2015;47(3):197-201. doi:10.1016/j.dld.2014.11.009.  10. Gonsalves N, Chehade M, Rothenberg ME, et al. Eosinophilic gastritis and eosinophilic duodenitis exhibit a similar clinical presentation, underscoring the need for collection of multiple biopsies from both the stomach and duodenum to evaluate for tissue eosinophilia. Poster presented at: Digestive Disease Week Virtual; May 21, 2021.  11. Pesek RD, Rothenberg ME. Eosinophilic gastrointestinal disease below the belt. J Allergy Clin Immunol.2020;145(1):87-89.e1. doi:10.1016/j.jaci.2019.10.013.  12. Youngblood BA, Brock EC, Leung J, et al. Monoclonal antibody reduces eosinophil and mast cell infiltration in a transgenic mouse model of eosinophilic gastroenteritis. JCI Insight.2019;4(19):e126219. doi:10.1172/jci.insight.126219.

ABOUT EG/EoD

Clinical presentation

Role of eosinophils and mast cells

Pathogenesis of EG/EoD

MORE COMMON THAN YOU THINK

EG/EoD prevalence study overview

EG/EoD prevalence study results

EG/EoD IS UNDERDIAGNOSED

Potential contributors to underdiagnosis

Misdiagnosis is common

Missed or delayed diagnosis frequently occurs

Patient cases: examples of diagnostic delay

HOW TO DETECT EG/EoD

Diagnostic algorithm

Biopsy protocol

Collaborating with your pathologist

FOR PATHOLOGISTS

Counting tissue eosinophils is key to diagnosis

Method for evaluating biopsy specimens for EG/EoD

MANAGEMENT OF EG/EoD
PROFESSIONAL RESOURCES

Recent evidence indicates that eosinophilic gastritis and/or eosinophilic duodenitis (EG/EoD) may be highly underdiagnosed.1-3

National Eosinophil Awareness Week May 16-22, 2021

Make EG/EoD part of the conversation #NEAW21 #EG_EoD
References:  1. Talley et al. To be presented at: Digestive Disease Week Virtual; May 22, 2021.  2. Alhmoud et al. Dig Dis Sci. 2016.  3. Licari et al. J Allergy Clin Immunol Pract. 2020.
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