STAT6 Variants Associate With Relapse of Eosinophilic Esophagitis in Patients Receiving Long-term Proton Pump Inhibitor Therapy.

BACKGROUND & AIMS: Based on histologic features, variants in STAT6 are associated with a poor initial response to proton pump inhibitor (PPI) therapy in pediatric patients with eosinophilic esophagitis (EoE). We investigated whether these genetic variants are associated with a poor long-term response in children with EoE who initially responded to PPI therapy. METHODS: We performed a prospective longitudinal cohort study of children ages 2 to 16 years who met the diagnostic criteria for EoE (≥15 eosinophils/high-power field [eos/hpf]), responded to 8 weeks of treatment with 2 mg/kg/d PPI (<15 eos/hpf), and whose dose then was reduced to 1 mg/kg/d PPI (maintenance therapy) for 1 year, at which point biopsy specimens were collected by endoscopy. Genomic DNA was isolated from formalin-fixed paraffin-embedded biopsy tissue and was genotyped for variants of STAT6. Remission of inflammation was assessed at eos/hpf thresholds of <15 and ≤5. RESULTS: Among 73 patients who received 1 mg/kg/d PPI maintenance therapy for 1 year, 13 patients (18%) had 6 to 14 eos/hpf, 36 patients (49%) had 5 or fewer eos/hpf, and 24 patients (33%) relapsed to EoE (≥15 eos/hpf). Carriage of any of 3 STAT6 variants in linkage disequilibrium (r2 ≥0.8; rs324011, rs167769, or rs12368672) was associated with a 2.3- to 2.8-fold increase in the odds of EoE relapse, and with a 2.8- to 4.1-fold increase in the odds of having 6 to 14 eos/hpf. For rs324011, the odds ratio [95% CI] for relapse was 2.77 [1.11, 6.92]; P = .029, and the odds ratio [95% CI] for having 6 to 14 eos/hpf was 3.06 [1.27, 7.36]; P = .012. CONCLUSIONS: Pediatric EoE patients who initially respond to PPI therapy and carry STAT6 variants rs324011, rs167769, or rs12368672 are at increased risk of relapse after 1 year of PPI maintenance therapy.

Proton-pump Inhibitor Response Prediction Using Esophageal microRNAs in Children With Eosinophilic Esophagitis.

OBJECTIVES: Eosinophilic esophagitis (EoE) is a chronic esophageal disease characterized by eosinophilic inflammation. Proton-pump inhibitors (PPI) induce disease remission but no predictive factors of PPI-responsiveness have been identified yet. So, a biomarker must be found to differentiate between responders (PPI-R) and nonresponder patients (PPI-NR) to PPI. Aims were to identify any molecular biomarker that could predict PPI responsiveness and to study molecular remission after PPI therapy. METHODS: This prospective study enrolled 39 controls and 43 pediatric children with EoE from 2 hospitals, and they were treated with esomeprazole for 8 to 12 weeks. After therapy, patients were classified as either PPI-R or PPI-NR. Biopsies were collected and RNA, microRNAs, and proteins were isolated from them, measuring levels by qPCR and Western blot (WB). Also, miRNAs were evaluated in serum. RESULTS: We found several esophageal miRNAs with different expression values between PPI-R and PPI-NR children, which can be used to discriminate them (area under curve = 0.90). No useful serum miRNAs were, however, identified. Also, these miRNAs were dysregulated in responder patients before and after PPI therapy. Moreover, we corroborated in this child population, that PPI-R displayed a significant decrease in eotaxin-3, IL-5, IL-13, periostin, and major basic protein (P < 0.05) and a significant increase in filaggrin levels after PPI treatment (P < 0.01). CONCLUSIONS: Esophageal miRNA levels found are able to discriminate between both PPI-R and PPI-NR at baseline, and before and after treatment in PPI-R, so they could be used as biomarkers. Furthermore, we observed clinical and esophageal molecular restoration in PPI-R patients after PPI therapy.

Food Protein-induced Enterocolitis Syndrome: Data From a Multicenter Retrospective Study in Spain.

OBJECTIVE: The aim of the study was to describe clinical, epidemiological, and management characteristics of food protein-induced enterocolitis syndrome (FPIES) cases in Spain. PATIENTS AND METHODS: Multicenter observational retrospective study. FPIES cases diagnosed in specialized units in Spain over 12 months in 2017 (January-December) according to the recently published international diagnostic criteria were included. RESULTS: One hundred twenty patients (53.3% boys) were included. The majority were acute cases (111) with mild-to-moderate severity (76.7%). Triggering foods were cow's milk (48/120), fish (38), egg (13), rice (12), and soy (1). The majority (84.2%) of the patients had FPIES to 1 food only. In addition to vomiting (100%), pallor (89.2%), and altered behavior (88.3%) were most frequently observed in acute forms. On the contrary, diarrhea (70%), abdominal distension (33.3%), and blood in stools (44.4%) were more frequently observed in chronic cases. Oral challenge was performed in 18.9% of the acute forms compared to 44.4% of the chronic forms. The most common treatment was intravenous fluids followed by ondansetron. Corticosteroids were used in 6 patients (5 with acute symptoms and 1 chronic). Seven patients were treated with antibiotics for suspicion of infection. Most cases of cow's milk FPIES were treated with extensively hydrolyzed formulas (69.8%). CONCLUSIONS: FPIES is not uncommon in our units. Unlike other published series, fish and egg are important triggers in our country. A greater knowledge and diffusion of the international consensus criteria will allow a better characterization of the cases and a standardization of their management.

Prevalence of Celiac Disease in a Long-term Study of a Spanish At-genetic-risk Cohort From the General Population.

OBJECTIVES: To perform long-term celiac disease (CD) screening in an HLA-DQ2 (+) cohort from the general population and to assess the influence of risk genotypes on its development. METHODS: In 2004, an HLA-DQ2 (+) cohort was selected. After the first CD screening at age 2 to 3 years, we performed a follow-up screening 8 to 10 years later. Antitransglutaminase 2 antibodies were determined using a rapid test kit. Results were confirmed by serum IgA antitransglutaminase 2 and IgA endomysial antibody determination. CD diagnosis was carried out by intestinal biopsies. Four HLA-DQ2 genotypic groups were used: G1: DQ2.5/DQ2.5 (G1A) or DQ2.5/ DQ2.2 (G1B); G2: DQ2.2/DQ7.5 (DQ2.5 trans); G3: DQ2.5/ X; G4: DQ2.2/X. RESULTS: CD prevalence after 10 years of follow-up was 5.8% (95% confidence interval 3.8-8.7). One of every 3 HLA-DQ2(+) children carried at least 1 haplotype DQ2.2 or DQ7. The homozygous genotype DQ2.5/DQ2.5 and the HLA-DQ2.5 trans genotype increased CD risk 4- and 3-fold, respectively. The homozygous genotype DQ2.5/ DQ2.2 did not increase the CD risk. Children carrying G1 or G2 genotypes were diagnosed with CD earlier and more frequently during the follow-up compare with those carrying G3 or G4 genotypes. Approximately 81% of children with spontaneous antibody negativization after the first screening maintained negative antibodies. CONCLUSIONS: A repeated screening of at-risk children during their follow-up allowed us to diagnose new CD cases. In our cohort, HLA- DQ2.5 trans genotype conferred a higher risk in the development of CD than HLA- DQ2.5/DQ2.2. The majority of children with potential CD and CD autoimmunity at 10 years of age remained healthy.

CYP2C19 and STAT6 Variants Influence the Outcome of Proton Pump Inhibitor Therapy in Pediatric Eosinophilic Esophagitis.

OBJECTIVE: Proton pump inhibitors (PPIs) are an effective treatment for eosinophilic esophagitis (EoE); however, only 30% to 60% of patients respond. Common genetic variants in CYP2C19 and STAT6 associate with PPI plasma concentration and magnitude of inflammatory response, respectively. Our objective was to determine if genetic variation in the genes for CYP2C19 and STAT6 influence differentiation between PPI responsive esophageal eosinophilia versus PPI nonresponsive EoE (PPI-REE, PPI-nonresponsive EoE). METHODS: Genomic DNA was isolated from 92 esophageal tissue biopsies collected from participants of a prospective clinical trial of high-dose PPI therapy for esophageal eosinophilia in children. RESULTS: Of the 92 patients examined, 57 (62%) were PPI-REE and 35 (38%) were PPI-nonresponsive EoE. Forty-six of the 92 patients were further characterized by pH probe monitoring; there was no association between reflux index and carriage of CYP2C1917 (P = 0.35). In children who received a PPI dose between ≥1.54 and ≤2.05 mg/kg/day, binary logistic regression modeling showed that carriage of CYP2C1917 associated with PPI-nonresponsive EoE (odds ratio (OR) [95% confidence interval (CI)] = 7.71 [1.21, 49.11], P = 0.031). Carriage of STAT6 allelic variant rs1059513 predicts PPI-REE (OR [95% CI] = 6.16 [1.44, 26.4], P = 0.028), whereas carriage of STAT6 rs324011 synergizes with CYP2C1917 to predict PPI-nonresponsive EoE (rs324011 OR [95% CI] = 5.56 [1.33, 20.72], P = 0.022; CYP2C1917 OR [95% CI] = 8.19[1.42, 50.57], P = 0.023). CONCLUSIONS: Common variants in CYP2C19 and STAT6 associate with a PPI-nonresponsive EoE outcome of PPI therapy for esophageal eosinophilia suggesting that response rates may be improved by adopting a genotype-guided approach to PPI dosing.

Long-term Treatment With Proton Pump Inhibitors Is Effective in Children With Eosinophilic Esophagitis.

OBJECTIVES: Proton pump inhibitor (PPI)-responsive eosinophilic esophagitis (EoE) is frequently observed in children, but data on long-term treatment are scarce. The objective of this study is to evaluate the long-term efficacy and safety of PPIs in children with EoE. METHODS: This prospective study enrolled children with EoE and histological remission to an 8-week esomeprazole trial (1 mg/kg/dose, twice daily). Esomeprazole was maintained at 1 mg/kg/day for 1 year. Symptom recurrence and adverse events were monitored and a follow-up endoscopy was performed at 12 months. Complete histological remission was defined as ≤5 eosinophils/high-power field (eos/hpf), and partial histological remission as >5 and <15 eos/hpf. Patients had no concomitant dietary restrictions or topical steroid. RESULTS: Fifty-seven children were included. Histological remission on maintenance PPI therapy was present in 40 children (70.1%; 95% CI 56.5-81.5). Long-term remission rate was higher in children with initial complete histological remission than in those with partial remission (81% vs 50%, P = 0.014). Forty-nine children (86%) remained asymptomatic. Pretreatment clinical and histological findings and median PPI dose/kg/day were similar between relapsers and nonrelapsers. Eleven out of 12 children (91.6%) receiving esomeprazole 0.5 mg ·â€Škg ·â€Š day for 12 additional months remained in remission. Mild and transient side effects without requiring PPI avoidance were observed in 5 children. CONCLUSIONS: Up to 70% of children with PPI-responsive EoE remain in histological and clinical remission on a low-dose maintenance treatment at 1-year follow-up, with adequate safety profile. Complete histological remission to an 8-week PPI trial was associated with higher probability of histological remission on maintenance therapy.

Prevalence and Natural History of Celiac Disease in a Cohort of At-risk Children.

OBJECTIVES: To assess the prevalence and clinical presentation of celiac disease (CD) in a cohort of children with HLA-DQ2 positive and evaluate the risk factors in the development of CD. METHODS: Between July 2004 and July 2005, parents of all healthy full-term newborns in our hospital were invited to participate. HLA-DQ2 was tested in blood sample of the umbilical cord. A point of contact serological test was performed on children between 2 and 3 years of age. Positive results were confirmed by serum anti-transglutaminase 2 and endomysial antibodies. Children with high autoantibody titers underwent an intestinal biopsy. Children of the cohort diagnosed with CD before the screening study were included. Sex, mode of delivery, breast-feeding duration, and age of gluten introduction were studied. RESULTS: Of 1291 children, 362 were HLA-DQ2 positive and 262 participated in the study. CD was diagnosed in 4.1% (95% confidence interval (CI) 1.9-6.3). In the whole cohort, 60% had gastrointestinal symptoms, 7% poor weight gain, and 33% were asymptomatic. Five children with potential CD and 6 with CD autoimmunity became negative (42.3%) and are still negative after 5 to 7 years. Female sex was at-risk factor odds ratio 5.7 (95% CI 1.5-20.9), whereas breast-feeding during gluten introduction had a protective effect odds ratio 0.1 (95% CI 0.01-0.8). CONCLUSIONS: Prevalence of CD in this cohort was 4%, half of whom had digestive symptoms. Because a high proportion of children showed a spontaneous disappearance of antibodies, prevalence studies of CD in young children should be based on intestinal damage so as not to overestimate results.

High Prevalence of Response to Proton-pump Inhibitor Treatment in Children With Esophageal Eosinophilia.

OBJECTIVES: Proton-pump inhibitor-responsive esophageal eosinophilia is a newly recognized entity with an unclear prevalence in children, as only retrospective data are available. The aim of this study was to determine the prevalence and clinical features of proton-pump inhibitor-responsive esophageal eosinophilia in children. METHODS: This prospective study enrolled patients with esophageal symptoms and esophageal eosinophilic counts as 15 or more than 15 eos/hpf (eosinophils per high-power field). Children received treatment with esomeprazole 1 mg ·â€Škg per dose twice daily for 8 weeks and the endoscopy was repeated. Complete response to proton-pump inhibitor (PPI) was defined as 5 or less than 5 eos/hpf, and a partial response as >5 and <15 eos/hpf in post-treatment biopsies. RESULTS: Fifty-one children (74.5% boys) were included. Histological response was observed in 35 children (68.6%): 24 children (47%) had a complete response and 11 children (21.6%) had a partial response. Only 16 children (31.4%) were diagnosed with eosinophilic esophagitis (EoE). There were no differences in history of atopy, allergy tests, pH study results, and endoscopic scores. Clinical symptoms were similar, with the exception of food impaction, which was more frequent in children with EoE (56.2% vs 20%, P = 0.01). The mean pretreatment peak eosinophil count was higher in patients with EoE (74.8 ±â€Š36.2 vs 46.3 ±â€Š30.7, P = 0.007). Eleven of the 14 patients (78.6%) on a lower PPI treatment maintenance dose remained in clinicopathologic remission at 1-year follow-up. CONCLUSIONS: A significant proportion of children with esophageal eosinophilia responded to high dose PPI treatment. Clinical, endoscopic, and pH study results were similar, with exception of patients with EoE, who were more likely to experience food impaction and have higher esophageal eosinophil counts.

The Role of Proton Pump Inhibitors in the Management of Pediatric Eosinophilic Esophagitis.

Eosinophilic esophagitis (EoE) is a chronic, local, immune-mediated disorder characterized by symptoms of esophageal dysfunction and the presence of a dense eosinophilic infiltrate in the esophageal mucosa. Consensus diagnostic recommendations for EoE diagnosis included absence of histological response to a proton-pump inhibitor (PPI) trial, to exclude gastro-oesophageal reflux disease (GERD)-associated esophagitis. This recommendation exposed an entity known as "proton pump inhibitor-responsive esophageal eosinophilia" (PPI-REE), which refers to patients with EoE phenotype who are PPI-responsive and do not present GERD. In recent years, there is evidence which indicates that PPI-REE is a sub-phenotype of EoE with similar clinical, endoscopic, histological and genetic characteristics, as well as Th2-related inflammatory response. As a result, PPIs should be considered another treatment for EoE and not a diagnostic tool. PPI-REE was originally described in a case series which included two children and in two retrospective pediatric series. Later, a prospective pediatric study showed a high rate of response to PPIs at high doses with long-term maintenance at lower doses. PPI monotherapy in children with esophageal eosinophilia (EE) has been observed to reduce eotaxin-3 expression in epithelial cells and to practically reverse the allergy and inflammatory transcriptome. These data reveal that PPIs are also an effective treatment for EoE in pediatric patients, although more studies are necessary in order to define the best induction and maintenance treatment regimen, the long-term safety profile and their influence on the occurrence of fibrosis and esophageal remodeling.