Human germline heterozygous gain-of-function STAT6 variants cause severe allergic disease

STAT6 (signal transducer and activator of transcription 6) is a transcription factor that plays a central role in the pathophysiology of allergic inflammation. We have identified 16 patients from 10 families spanning three continents with a profound phenotype of early-life onset allergic immune dysregulation, widespread treatment-resistant atopic dermatitis, hypereosinophilia with esosinophilic gastrointestinal disease, asthma, elevated serum IgE, IgE-mediated food allergies, and anaphylaxis. The cases were either sporadic (seven kindreds) or followed an autosomal dominant inheritance pattern (three kindreds). All patients carried monoallelic rare variants in STAT6 and functional studies established their gain-of-function (GOF) phenotype with sustained STAT6 phosphorylation, increased STAT6 target gene expression, and TH2 skewing. Precision treatment with the anti-IL-4Rα antibody, dupilumab, was highly effective improving both clinical manifestations and immunological biomarkers. This study identifies heterozygous GOF variants in STAT6 as a novel autosomal dominant allergic disorder. We anticipate that our discovery of multiple kindreds with germline STAT6 GOF variants will facilitate the recognition of more affected individuals and the full definition of this new primary atopic disorder.

Food Allergy Management for Adolescents Using Behavioral Incentives: A Randomized Trial

OBJECTIVE

We sought to evaluate the use of behavioral economics approaches to promote the carrying of epinephrine auto-injectors (EAIs) among adolescents with food allergies. We hypothesized that adolescents who receive frequent text message nudges (Intervention 1) or frequent text message nudges plus modest financial incentives (Intervention 2) would be more likely to carry their epinephrine than members of the usual care control group.

METHODS

We recruited 131 adolescents ages 15 to 19 with a food allergy and a current prescription for epinephrine to participate in a cohort multiple randomized controlled trial. Participants were randomly assigned to participate in Intervention 1, Intervention 2, or to receive usual care. The primary outcome was consistency of epinephrine-carrying, measured as the proportion of checkpoints at which a participant could successfully demonstrate they were carrying their EAI, with photo-documentation of the device.

RESULTS

During Intervention 1, participants who received the intervention carried their EAI 28% of the time versus 38% for control group participants (P = .06). During Intervention 2, participations who received the intervention carried their EAI 45% of the time versus 23% for control group participants (P = .002).

CONCLUSIONS

Text message nudges alone were unsuccessful at promoting EAI-carrying but text message nudges combined with modest financial incentives almost doubled EAI-carriage rates among those who received the intervention compared with the control group. However, even with the intervention, adolescents with food allergies carried their EAI <50% of the time. Alternative strategies for making EAIs accessible to adolescents at all times should be implemented.

Safety of Epicutaneous Immunotherapy in Peanut-Allergic Children: REALISE Randomized Clinical Trial Results

BACKGROUND

Treatment options for peanut allergy are limited. In previous clinical trials, epicutaneous immunotherapy with a patch containing 250-μg peanut protein (Viaskin Peanut 250 μg [VP250]) was well tolerated and statistically superior to placebo in desensitizing peanut-allergic children.

OBJECTIVE

To examine the safety of VP250 in children, using a study design approximating potential real-world use.

METHODS

REAL LIfe Use and Safety of EPIT (REALISE) is a phase 3 multicenter study consisting of a 6-month, randomized, double-blind, placebo-controlled period followed by open-label active treatment. Children aged 4 to 11 years with physician diagnosis of peanut allergy received daily treatment with placebo (6 months) or VP250 (up to 36 months). Data from the 6-month, randomized, controlled phase of REALISE are reported.

RESULTS

Three hundred ninety-three children were randomized 3:1 to receive VP250 (n = 294) or placebo (n = 99) for 6 months; 284 (72.3%) children had a history of peanut anaphylaxis. According to parent diary, all participants receiving VP250 and 83.8% receiving placebo reported at least 1 episode of local skin reaction, with frequency decreasing over time. Only 4 participants (1.4%) receiving VP250 discontinued because of adverse events (AEs). Epinephrine was administered for allergic reactions attributed to VP250 in 7 children (2.4%), of whom 5 remained in the study; none involved severe anaphylaxis. Overall, AE rates were similar among participants with and without a history of peanut anaphylaxis.

CONCLUSIONS

In a study designed to mirror real-world use, VP250 was observed to be well tolerated in peanut-allergic children, consistent with previous phase 2b and 3 studies.

Improvement in eosinophilic esophagitis when using dupilumab for other indications or compassionate use

BACKGROUND

Dupilumab has been approved to treat atopic dermatitis, asthma, and nasal polyps and is in active clinical trials for the treatment of eosinophilic esophagitis (EoE). Given its shared immunopathology, we hypothesized that EoE symptoms and inflammation would improve when dupilumab therapy was used for other allergic indications.

OBJECTIVE

To measure the clinical and histologic response in EoE to dupilumab when treating other atopic diseases.

METHODS

We completed a retrospective chart review of all patients at Children's Hospital of Philadelphia and Rady Children Hospital who were prescribed dupilumab for atopic dermatitis, asthma, or nasal polyps and had a concomitant clinical diagnosis of EoE. Demographic information along with histology, symptom scores, medications, and diet information were collected. Response to dupilumab was evaluated.

RESULTS

A total of 45 patients were identified. Of which, 11 patients were prescribed dupilumab for asthma, 27 for atopic dermatitis, 3 for nasal polyps, and 4 for compassionate use for EoE. There was no follow-up data for 8 patients. Follow-up histology was available for 26 patients: 22 of 26 had less than 6 eosinophils per high power field after the initiation of dupilumab with significant improvement (pre: 52.9 + 35.1 to post: 4.5 + 10.9 eosinophils/high power field, P < .005). A total of 28 patients had improvement of symptoms, with 24 patients reporting complete resolution of symptoms after dupilumab initiation. Reductions in EoE treatment medications (swallowed steroids, proton pump inhibitors) or expansion of diet occurred in 29 patients treated with dupilumab.

CONCLUSION

Dupilumab therapy initiated for atopic disease effectively induces symptomatic and histologic remission of esophageal disease and reduces the need for EoE-directed therapy in patients with concomitant EoE.

Improving allergy office scheduling increases patient follow up and reduces asthma readmission after pediatric asthma hospitalization

BACKGROUND

Pediatric asthma is a major contributor to emergency room utilization and hospital readmission rates.

OBJECTIVE

To develop an allergy department‒based intervention to improve follow-up appointment scheduling processes for pediatric asthma patients after discharge for asthma exacerbation.

METHODS

This quality improvement study was conducted in the allergy clinic of an urban, tertiary children's hospital. Children receiving subspecialty allergy care for asthma were included into the intervention group during the intervention period. The quality improvement intervention consisted of 3 attempts by telephone to reach the family to schedule the follow-up appointment. If this was unsuccessful or if the appointment was not kept, then a reminder letter was sent to the family. The primary outcome of interest in this study was the percent of postdischarge follow-up appointments scheduled within 30 days of discharge. Secondary outcomes measured were the percent of allergy appointments attended within 30 days of discharge and the 30-day hospital readmission rate.

RESULTS

Demographics did not differ significantly between the intervention and baseline preintervention year. The initial baseline scheduled allergy follow-up visit rate was 48.8 ± 13.3% of patients discharged per month. This increased to an overall rate of 75.7 ± 20.1% patients scheduling allergy follow-up within 30 days of discharge during the intervention year. We also observed a significant increase in attended allergy visits 30 days postdischarge from 35.5 ± 15.6% in year 1 to 53.9 ± 25.5% during the intervention year and a significant decrease in the 30-day readmission rate on the allergy service.

CONCLUSION

These data suggests that minor changes in allergy practice organization can significantly affect posthospitalization follow-up rates and decrease asthma readmission rates.

Medication contaminants as a potential cause of anaphylaxis to vincristine

Vincristine (VCR) is a vinca alkaloid and common chemotherapeutic that is used to treat multiple pediatric and adult malignancies. Despite its common use, cases of anaphylaxis to VCR are rare and typically isolated to a single individual. We report a series of eight patients with adverse reactions to VCR over the course of 11 months at a single institution, four of which progressed to anaphylaxis and one of which resulted in cardiac arrest. Mass spectrometry analysis of medication lots was performed to test for possible contaminant(s). Our findings highlight the risk of anaphylaxis during therapy with VCR.

Effect of Varying Doses of Epicutaneous Immunotherapy vs Placebo on Reaction to Peanut Protein Exposure Among Patients With Peanut Sensitivity: A Randomized Clinical Trial

IMPORTANCE

Epicutaneous immunotherapy may have potential for treating peanut allergy but has been assessed only in preclinical and early human trials.

OBJECTIVE

To determine the optimal dose, adverse events (AEs), and efficacy of a peanut patch for peanut allergy treatment.

DESIGN, SETTING, AND PARTICIPANTS

Phase 2b double-blind, placebo-controlled, dose-ranging trial of a peanut patch in peanut-allergic patients (6-55 years) from 22 centers, with a 2-year, open-label extension (July 31, 2012-July 31, 2014; extension completed September 29, 2016). Patients (n = 221) had peanut sensitivity and positive double-blind, placebo-controlled food challenges to an eliciting dose of 300 mg or less of peanut protein.

INTERVENTIONS

Randomly assigned patients (1:1:1:1) received an epicutaneous peanut patch containing 50 μg (n = 53), 100 μg (n = 56), or 250 μg (n = 56) of peanut protein or a placebo patch (n = 56). Following daily patch application for 12 months, patients underwent a double-blind, placebo-controlled food challenge to establish changes in eliciting dose.

MAIN OUTCOMES AND MEASURES

The primary efficacy end point was percentage of treatment responders (eliciting dose: ≥10-times increase and/or reaching ≥1000 mg of peanut protein) in each group vs placebo patch after 12 months. Secondary end points included percentage of responders by age strata and treatment-emergent adverse events (TEAEs).

RESULTS

Of 221 patients randomized (median age, 11 years [quartile 1, quartile 3: 8, 16]; 37.6% female), 93.7% completed the trial. A significant absolute difference in response rates was observed at month 12 between the 250-μg (n = 28; 50.0%) and placebo (n = 14; 25.0%) patches (difference, 25.0%; 95% CI, 7.7%-42.3%; P = .01). No significant difference was seen between the placebo patch vs the 100-μg patch. Because of statistical testing hierarchical rules, the 50-μg patch was not compared with placebo. Interaction by age group was only significant for the 250-μg patch (P = .04). In the 6- to 11-year stratum, the response rate difference between the 250-μg (n = 15; 53.6%) and placebo (n = 6; 19.4%) patches was 34.2% (95% CI, 11.1%-57.3%; P = .008); adolescents/adults showed no difference between the 250-μg (n = 13; 46.4%) and placebo (n = 8; 32.0%) patches: 14.4% (95% CI, -11.6% to 40.4%; P = .40). No dose-related serious AEs were observed. The percentage of patients with 1 or more TEAEs (largely local skin reactions) was similar across all groups in year 1: 50-μg patch = 100%, 100-μg patch = 98.2%, 250-μg patch = 100%, and placebo patch = 92.9%. The overall median adherence was 97.6% after 1 year; the dropout rate for treatment-related AEs was 0.9%.

CONCLUSIONS AND RELEVANCE

In this dose-ranging trial of peanut-allergic patients, the 250-μg peanut patch resulted in significant treatment response vs placebo patch following 12 months of therapy. These findings warrant a phase 3 trial.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01675882.

Seasonal exacerbation of esophageal eosinophilia in children with eosinophilic esophagitis and allergic rhinitis

BACKGROUND

Evidence supports a possible link between eosinophilic esophagitis (EoE) and environmental aeroallergens, which can manifest as seasonal exacerbation of esophageal eosinophilia. Few studies have examined this link in pediatric patients with EoE.

OBJECTIVE

To identify the proportion of patients with seasonal induced esophageal eosinophilia.

METHODS

A retrospective chart review was conducted of all patients diagnosed with EoE at the authors' institution. Demographic data were collected by chart review. Seasonal variation or flare was defined as a change from fewer than to at least 15 eosinophils per high-power field and a minimum of a 2-fold increase in eosinophil count between 2 consecutive biopsy specimens in different seasons without dietary or medication modifications.

RESULTS

Of the 1,180 patients with EoE, 160 (14%) were suspected of having aeroallergen-associated triggers by history. Of these 160 patients, 32 (20%) had biopsy examination-confirmed variation of EoE triggered by aeroallergens. Most of these patients were boys (84%), all had a history or examination consistent with allergic rhinitis, and most had a history of asthma (75%). Thirty-two subjects had obvious seasonal variation, 22 of whom also had known food-induced symptoms.

CONCLUSION

Children with EoE and allergic rhinitis might have exacerbations in their esophageal eosinophilia during certain seasons depending on the specific aeroallergens to which they are sensitized. Identification of environmental allergens to sensitized patients is important and can guide therapy.

The link between allergies and eosinophilic esophagitis: implications for management strategies

Eosinophilic esophagitis (EE) has an increased incidence of diagnosis similar to other atopic diseases. We present a recent literature review of the common features between atopic diseases (i.e., asthma, allergic rhinitis and atopic dermatitis) and EE. All of the disorders have allergen triggers and evidence of a possible Th2 inflammation at the site of disease. Murine models have also shown similar features with the importance of T cells and Th2 cytokines for the development of disease. The diseases share underlying inflammation with the potential for remodeling with an increase in TGF-beta expression in asthma and EE. However, differences do exist between the diseases in treatment and pathogenesis. For EE, there are two basic treatment options: avoidance of the food triggers or treatment of the eosinophilic inflammation with corticosteroids.

Treatment of eosinophilic esophagitis with specific food elimination diet directed by a combination of skin prick and patch tests

BACKGROUND

Eosinophilic esophagitis (EE) is a recently described disorder identified in patients with symptoms suggestive of gastroesophageal reflux disease (GERD) but unresponsive to conventional reflux therapies. Therapies have included corticosteroids, elemental diet, and diet restriction. We report our experience with skin prick and atopy patch testing and food elimination diets in patients diagnosed as having EE.

OBJECTIVE

To identify food antigens that cause EE and the characteristics of patients who respond to food elimination vs those who are unresponsive.

METHODS

Patients diagnosed as having EE had restricted diets based on skin prick and atopy patch testing results. Additional biopsies were performed after 4 to 8 weeks of restricted diet. Demographics, atopic tendencies, and food antigens were identified retrospectively in our food allergy database.

RESULTS

A total of 146 patients diagnosed as having EE were evaluated with skin prick and atopy patch testing. Thirty-nine patients had unequivocal demonstration of food causing EE, with normalization of biopsy results on elimination and reoccurrence on reintroduction. An additional 73 patients, for a total 112 (77%) of 146 patients, had resolution of their EE as demonstrated by biopsy results. Fifteen (10%) of 146 patients were nonresponders manifested by no significant reduction in esophageal eosinophils despite restricted diet based on skin prick and atopy patch testing. Egg, milk, and soy were identified most frequently with skin prick testing, whereas corn, soy, and wheat were identified most frequently with atopy patch testing.

CONCLUSION

In more than 75% of patients with EE, both symptoms and esophageal inflammation can be significantly improved with dietary elimination of foods. Skin prick and atopy patch testing can help identify foods in most patients.

Association of toxic shock syndrome toxin-secreting and exfoliative toxin-secreting Staphylococcus aureus with Kawasaki syndrome complicated by coronary artery disease

Kawasaki syndrome (KS) has been reported to be associated with selective expansion of Vbeta2+ T cells and either staphylococcal toxic shock syndrome toxin-1 or streptococcal pyrogenic exotoxin C in uncomplicated cases. However, there have been no previous studies on the role of superantigens in KS associated with coronary artery disease, the major complication of this illness. The present study characterized bacteria isolated from three acute KS patients who developed coronary artery disease. Staphylococcus aureus secreting either TSST-1 (n = 3) or exfoliative toxin A (n = 1), both known to stimulate expansion of Vbeta2+ T cells, were isolated from all three patients. The percent Vbeta2+ T cells was determined in three patients with coronary artery disease. On presentation, one patient demonstrated reduction, whereas the other two showed expansion, of Vbeta2+ T cells. Repeat analyses of the latter two children showed their percent Vbeta2+ T cells to decrease toward normal. These observations suggest that coronary artery disease in KS may result from superantigenic stimulation of Vbeta2+ T cells. This is also the first demonstration of an association of staphylococcal exfoliative toxin with acute KS. The observation that three different bacterial toxins associated with KS are potent activators of Vbeta2+ T cells suggests an important role for this T cell subset in the pathogenesis of this autoimmune disease.