Wright, Benjamin L.

Background Diagnosis of non-esophageal eosinophilic gastrointestinal disorders requires quantification of tissue eosinophils. Our objective was to evaluate eosinophil peroxidase (EPX) immunohistochemistry (IHC) as a method for histologic diagnosis of eosinophilic gastritis (EG) and eosinophilic duodenitis (EoD). Methods We performed a retrospective analysis of biopsies from pediatric EG/EoD cases and controls. Subjects with EG or EoD had ≥30 eosinophils per high power field (eos/hpf) in ≥5 hpf in the stomach and/or ≥3 hpf in the duodenum, respectively. Controls had no histopathologic diagnosis recorded. Tissue eosinophil counts were assessed by hematoxylin & eosin stains. EPX stains were assessed using a unique histopathologic scoring system. Slides were digitized and EPX+ staining area/mm 2 was quantified by image analysis. Results Twenty-six EG/EoD cases and 40 controls were analyzed. EPX scores and EPX/mm 2 levels were markedly elevated in EG/EoD (p ≤ 0.0001). Eosinophil density (eos/mm 2 ) correlated strongly with EPX scores and EPX/mm 2 levels in the stomach (r ≥ 0.77) and moderately with EPX scores and EPX/mm 2 levels in the duodenum (r ≥ 0.52); (p < 0.0001). EPX quantification identified EG/EoD subjects with high diagnostic accuracy (EPX score: AUC = 1 for EG and EoD; EPX/mm 2 : AUC = 0.98 (95%CI 0.96-1) for EG, AUC = 0.91 (95%CI 0.81-1) for EoD). Conclusion EPX-based assessment of eosinophilic inflammation may facilitate automated histologic diagnosis.

Background: Food protein‐induced enterocolitis syndrome (FPIES) is a non-immunoglobulin E mediated food allergy that typically presents with repetitive emesis and may be associated with lethargy, marked pallor, hypotension, hypothermia, and/or diarrhea. Although many foods are known to cause FPIES, peanut-triggered FPIES is emerging due to changes in the feeding practice guidelines, which recommends early peanut introduction in infants. Objective: We aimed to characterize peanut-triggered acute FPIES cases in our pediatric population and to describe their attributes, treatment, and outcomes. We hypothesized that increases in the incidence of peanut-triggered FPIES coincided with implementation of the guidelines for early peanut introduction. Methods: A retrospective chart review was conducted of pediatric patients who presented to Phoenix Children’s Hospital Emergency Department and subspecialty clinics during a 6-year period (January 2013 to September 2019). Results: Thirty-three cases of patients with acute FPIES were identified, five of which were peanut triggered. In those patients with peanut-triggered FPIES, the median age for peanut introduction was 7 months (range, 5‐24 months). Two patients had positive peanut skin-prick test results. All five cases were identified in the past 2 years (2018 to 2019). No peanut-triggered reactions were documented in the preceding 4-year period (2013 to 2017). Conclusion: Peanut may be an emerging trigger of acute FPIES, coinciding with an earlier introduction of peanut in the infant diet after implementation of the new addendum guidelines for the prevention of peanut allergy. Oats and rice were the most common triggers of acute FPIES in our cohort. Further study will help clarify the significance and reproducibility of these findings.

Background PFAPA (periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis) syndrome is diagnosed clinically. Adult-onset PFAPA syndrome is rare and often has a more diverse clinical presentation that its childhood counterpart. This is the first reported case of adult-onset PFAPA syndrome with complete response to lingual tonsillectomy. Case Summary A 41-year-old man was evaluated for periodic fevers associated with uvulitis, cervical lymphadenitis, pharyngitis, and lower extremity rash. He had a variable response to steroids and was intolerant of colchicine. Laboratory workup revealed intermittent elevation of erythrocyte sedimentation rate and C-reactive protein level. Computed tomography neck and laryngoscopy confirmed adenoidal and lingual tonsillar hypertrophy. He underwent adenoidectomy and lingual tonsillectomy with resolution of symptoms. Conclusions Hypertrophy of the remaining lymphoid structures within Waldeyer's ring may be associated with remote recurrence of PFAPA syndrome after tonsillectomy. Lingual tonsillectomy may be an alternative treatment strategy in select patients with PFAPA, prominent lingual hypertrophy, and incomplete response to steroids.

Summary As the awareness among gastroenterologists regarding endoscopic features suggesting eosinophilic esophagitis is increasing, individuals without symptoms of esophageal dysfunction are increasingly being found to have esophageal eosinophilia on biopsies performed during upper gastrointestinal endoscopies. However, the course of disease and the management of these asymptomatic individuals with esophageal eosinophilia remain elusive. In this review, we propose a definition of asymptomatic individuals with esophageal eosinophilia and discuss the prevalence, risk factors, and course of disease of this specific patient group. Furthermore, we have established a diagnostic and therapeutic pathway based on the most recent available data.

OBJECTIVES: Dietary elimination for treatment of eosinophilic esophagitis (EoE) is limited by lack of accuracy in current allergy tests. We aimed to develop an immunologic approach to identify dietary triggers and prospectively test allergen-specific immune signature-guided dietary elimination therapy. METHODS: In the first phase, we developed and assessed 2 methods for determining selected food triggers using samples from 24 adults with EoE: a CD4+ T-cell proliferation assay in peripheral blood and food-specific tissue IgG4 levels in esophageal biopsies. In the second phase, we clinically tested elimination diets created from these methods in a prospective cohort treated for 6 weeks (NCT02722148). Outcomes included peak eosinophil counts (eos/hpf), endoscopic findings (measured by the EoE Endoscopic Reference Score), and symptoms (measured by the EoE Symptom Activity Index). RESULTS: Parameters were optimized with a positive test on either assay, yielding agreements of 60%, 75%, 53%, 58%, and 53% between predicted and known triggers of peanut, egg, soy, wheat, and milk, respectively. In clinical testing, the mean number of foods eliminated based on the assays was 3.4, and 19 of 22 subjects were compliant with treatment. After treatment, median peak eosinophil counts decreased from 75 to 35 ( P = 0.007); there were 4 histologic responders (21%). The EoE Endoscopic Reference Score and EoE Symptom Activity Index score also decreased after treatment (4.6 vs 3.0; P = 0.002; and 32.5 vs 25.0; P = 0.06, respectively). DISCUSSION: We successfully developed a new testing approach using CD4 + T-cell proliferation and esophageal food-specific IgG4 levels, with promising accuracy rates. In clinical testing, this led to improvement in eosinophil counts, endoscopic severity, and symptoms of dysphagia, but a smaller than expected number of patients achieved histologic remission.

SUMMARYEosinophil peroxidase is an eosinophil-specific, cytoplasmic protein stored in the secondary granules of eosinophils. While eosinophil peroxidase deposition is increased in the esophagus in eosinophilic esophagitis (EOE), its potential role as a peripheral marker is unknown. This study aims to examine the relationship between serum eosinophil peroxidase and esophageal eosinophilia in eosinophilic esophagitis. Prospectively collected serum from 19 subjects with incident EoE prior to treatment and 20 non-EoE controls were tested for serum eosinophil peroxidase, eosinophilic cationic protein, and eosinophil derived neurotoxin using ELISA. Matching esophageal tissue sections were stained and assessed for eosinophil peroxidase deposition using a histopathologic scoring algorithm. Mean peripheral blood absolute eosinophil counts in eosinophilic esophagitis subjects were significantly elevated compared to controls (363 vs. 195 cells/μL,P = 0.008). Absolute median serum eosinophil peroxidase, eosinophil cationic protein, and eosinophil derived neurotoxin did not differ between groups; however, when normalized for absolute eosinophil counts, eosinophilic esophagitis subjects had significantly lower median eosinophil peroxidase levels (2.56 vs. 6.96 ng/mL per eos/μL,P = 0.002, AUC 0.79 (0.64, 0.94 95% CI)). Multivariate analysis demonstrated this relationship persisted after controlling for atopy. Esophageal biopsies from eosinophilic esophagitis subjects demonstrated marked eosinophil peroxidase deposition (median score 46 vs. 0,P &lt; 0.0001). Normalized eosinophil peroxidase levels inversely correlated with esophageal eosinophil density (r = −0.41,P = 0.009). In contrast to marked tissue eosinophil degranulation, circulating eosinophils appear to retain their granule proteins in EoE. Investigations of normalized serum eosinophil peroxidase levels as a biomarker of EoE are ongoing.