Tamara T. Perry

Clinical efficacy and immune regulation with peanut oral immunotherapy

BACKGROUND Oral immunotherapy (OIT) has been thought to induce clinical desensitization to allergenic foods, but trials coupling the clinical response and immunologic effects of peanut OIT have not been reported. OBJECTIVE The study objective was to investigate the clinical efficacy and immunologic changes associated with OIT. METHODS Children with peanut allergy underwent an OIT protocol including initial day escalation, buildup, and maintenance phases, and then oral food challenge. Clinical response and immunologic changes were evaluated. RESULTS Of 29 subjects who completed the protocol, 27 ingested 3.9 g peanut protein during food challenge. Most symptoms noted during OIT resolved spontaneously or with antihistamines. By 6 months, titrated skin prick tests and activation of basophils significantly declined. Peanut-specific IgE decreased by 12 to 18 months, whereas IgG(4) increased significantly. Serum factors inhibited IgE-peanut complex formation in an IgE-facilitated allergen binding assay. Secretion of IL-10, IL-5, IFN-gamma, and TNF-alpha from PBMCs increased over a period of 6 to 12 months. Peanut-specific forkhead box protein 3 T cells increased until 12 months and decreased thereafter. In addition, T-cell microarrays showed downregulation of genes in apoptotic pathways. CONCLUSION Oral immunotherapy induces clinical desensitization to peanut, with significant longer-term humoral and cellular changes. Microarray data suggest a novel role for apoptosis in OIT.

A randomized controlled study of peanut oral immunotherapy: Clinical desensitization and modulation of the allergic response

BACKGROUND Open-label oral immunotherapy (OIT) protocols have been used to treat small numbers of patients with peanut allergy. Peanut OIT has not been evaluated in double-blind, placebo-controlled trials. OBJECTIVE To investigate the safety and effectiveness of OIT for peanut allergy in a double-blind, placebo-controlled study. METHODS In this multicenter study, children ages 1 to 16 years with peanut allergy received OIT with peanut flour or placebo. Initial escalation, build-up, and maintenance phases were followed by an oral food challenge (OFC) at approximately 1 year. Titrated skin prick tests (SPTs) and laboratory studies were performed at regular intervals. RESULTS Twenty-eight subjects were enrolled in the study. Three peanut OIT subjects withdrew early in the study because of allergic side effects. During the double-blind, placebo-controlled food challenge, all remaining peanut OIT subjects (n = 16) ingested the maximum cumulative dose of 5000 mg (approximately 20 peanuts), whereas placebo subjects (n = 9) ingested a median cumulative dose of 280 mg (range, 0-1900 mg; P < .001). In contrast with the placebo group, the peanut OIT group showed reductions in SPT size (P < .001), IL-5 (P = .01), and IL-13 (P = .02) and increases in peanut-specific IgG(4) (P < .001). Peanut OIT subjects had initial increases in peanut-specific IgE (P < .01) but did not show significant change from baseline by the time of OFC. The ratio of forkhead box protein 3 (FoxP3)(hi): FoxP3(intermediate) CD4+ CD25+ T cells increased at the time of OFC (P = .04) in peanut OIT subjects. CONCLUSION These results conclusively demonstrate that peanut OIT induces desensitization and concurrent immune modulation. The current study continues and is evaluating the hypothesis that peanut OIT causes long-term immune tolerance.

Sustained unresponsiveness to peanut in subjects who have completed peanut oral immunotherapy

BACKGROUND Although peanut oral immunotherapy (OIT) has been conclusively shown to cause desensitization, it is currently unknown whether clinical protection persists after stopping therapy. OBJECTIVE Our primary objective was to determine whether peanut OIT can induce sustained unresponsiveness after withdrawal of OIT. METHODS We conducted a pilot clinical trial of peanut OIT at 2 US centers. Subjects age 1 to 16 years were recruited and treated for up to 5 years with peanut OIT. The protocol was modified over time to permit dose increases to a maximum of 4000 mg/d peanut protein. Blood was collected at multiple time points. Clinical end points were measured with 5000-mg double-blinded, placebo-controlled food challenges once specific criteria were met. RESULTS Of the 39 subjects originally enrolled, 24 completed the protocol and had evaluable outcomes. Twelve (50%) of 24 successfully passed a challenge 1 month after stopping OIT and achieved sustained unresponsiveness. Peanut was added to the diet. At baseline and the time of challenge, such subjects had smaller skin test results, as well as lower IgE levels specific for peanut, Ara h 1, and Ara h 2 and lower ratios of peanut-specific IgE/total IgE compared with subjects not passing. There were no differences in peanut IgG₄ levels or functional activity at the end of the study. CONCLUSIONS This is the first demonstration of sustained unresponsiveness after peanut OIT, occurring in half of subjects treated for up to 5 years. OIT favorably modified the peanut-specific immune response in all subjects completing the protocol. Smaller skin test results and lower allergen-specific IgE levels were predictive of successful outcome.

Adverse reactions during peanut oral immunotherapy home dosing

To The Editor: Oral immunotherapy (OIT) is increasingly being investigated as a potential treatment for peanut and other food allergies, with a recent study demonstrating evidence of clinical desensitization and immunologic changes suggesting the development of long-term tolerance1. Unlike traditional subcutaneous immunotherapy for inhalant allergens, peanut OIT is administered daily, with the vast majority of doses given at home. In our peanut OIT protocols, subjects are seen in the research unit for observed dose escalations every two weeks, and subsequent doses are given at home. In the open-label study of peanut OIT, home doses were generally well-tolerated2. The incidence of allergic reactions with any home dose was 3.5%, with mild upper respiratory and skin symptoms being the most common complaints. Despite the infrequent incidence of symptoms with peanut OIT home dosing, certain patterns of reactions have surfaced during this phase. Characterizing these reactions and identifying potential triggers or factors which predispose to reactions may improve the safety of home dosing. Reactions occurring during investigational OIT or any immunotherapy protocol are challenging to study prospectively, due to ongoing modifications in the protocol and recommendations that are instituted to prevent further reactions. In subcutaneous aeroallergen immunotherapy, asthma has been identified as a risk factor for systemic reactions, prompting recommendations to evaluate respiratory symptoms and consider objective measures of airway function during administration3. Researchers studying milk and egg OIT noted certain “augmentation factors” that lowered threshold doses – namely, infection, exercise, pollen allergy, and irregular intake4 – and identifying these factors and reducing the immunotherapy dose prevented further allergic reactions. We have noted five patterns associated with a propensity to react to a previously tolerated dose of peanut OIT, including several not previously described. It is interesting that these factors would provoke symptoms after a given OIT dose when, in many of the examples noted, the dose had been tolerated for weeks to months without symptoms. Table I lists selected examples illustrating the observed patterns – (1) concurrent illness, (2) suboptimally-controlled asthma, (3) timing of dose administration after food ingestion, (4) physical exertion after dosing, and (5) dosing during menses. Addressing these factors (see Table II) has improved the safety profile of our peanut OIT protocol. While some of our recommendations mirror those instituted in subcutaneous immunotherapy protocols, most are unique to OIT administration. We expand on reports from other research centers4, 5, which have described triggers such as infection, exercise, pollen allergy, and irregular intake, and this is the first report involving protocols for peanut allergy. Table I Examples of Reactions during Peanut OIT Home Dosing Table II Recommendations for Future OIT Investigations We have observed that dosing during febrile illnesses has been associated with systemic reactions to previously tolerated peanut OIT doses. We recommend withholding OIT during acute illnesses and advise subjects to resume dosing at home if fewer than three doses are missed. If three to five doses are missed, subjects return to the research unit for observed dosing. Those who miss more than five days of dosing may require significant dose reduction or repeat desensitization. In our open-label study2, asthma was associated with a higher rate of chest symptoms during OIT. Of the subjects reporting chest symptoms during home dosing, 82% had co-existing asthma. Several subjects receiving peanut OIT noted cough and wheezing after doses. Some also had chronic cough or exercise-induced respiratory symptoms. Although we did not observe changes in pulmonary function in these subjects, their symptoms improved with the initiation of asthma controller medications (see Table I), highlighting the importance of diagnosing and treating co-morbid atopic conditions. Regular peak flow measurements and pulmonary function testing has been implemented to optimize asthma control. It has not been uncommon for a subject taking a daily OIT dose without eating a meal or snack in the two hours before dosing to have symptoms with a dose that has been previously tolerated; taking the same dose with food the next day and thereafter prevents further reactions. Additionally, several subjects have experienced allergic symptoms with exercise after OIT dosing, and we advise these individuals to avoid exertion for two hours after dosing. Finally, one subject had several systemic reactions when menses was coupled with exercise despite no symptoms with daily dosing in the interval between episodes and was eventually withdrawn from the study. She was not taking other medications (e.g. non-steroidal anti-inflammatory drugs). Of note, she did not have systemic reactions each time she exercised during menses. At this time, the role of menses is unclear, and further study is needed. In the studies to date, peanut and food OIT have a good safety profile, and home dosing is infrequently associated with adverse reactions2, 6. However, allergic symptoms should be expected, and subjects and their families should be counseled about circumstances associated with an increased possibility of reacting to previously tolerated OIT doses. As OIT for food allergy becomes increasingly studied in research settings, implementing these recommendations and modifications can improve the safety of these experimental protocols.

Allergic reactions to foods in preschool-aged children in a prospective observational food allergy study.

OBJECTIVE: To examine circumstances of allergic reactions to foods in a cohort of preschool-aged children. METHODS: We conducted a prospective, 5-site observational study of 512 infants aged 3 to 15 months with documented or likely allergy to milk or egg, and collected data prospectively examining allergic reactions. RESULTS: Over a median follow-up of 36 months (range: 0–48.4), the annualized reaction rate was 0.81 per year (367/512 subjects reporting 1171 reactions [95% confidence interval: 0.76–0.85]). Overall, 269/512 (52.5%) reported >1 reaction. The majority of reactions (71.2%) were triggered by milk (495 [42.3%]), egg (246 [21.0%]), and peanut (93 [7.9%]), with accidental exposures attributed to unintentional ingestion, label-reading errors, and cross-contact. Foods were provided by persons other than parents in 50.6% of reactions. Of 834 reactions to milk, egg, or peanut, 93 (11.2%) were attributed to purposeful exposures to these avoided foods. A higher number of food allergies (P < .0001) and higher food-specific immunoglobulin E (P < .0001) were associated with reactions. Of the 11.4% of reactions (n = 134) that were severe, 29.9% were treated with epinephrine. Factors resulting in undertreatment included lack of recognition of severity, epinephrine being unavailable, and fears about epinephrine administration. CONCLUSIONS: There was a high frequency of reactions caused by accidental and nonaccidental exposures. Undertreatment of severe reactions with epinephrine was a substantial problem. Areas for improved education include the need for constant vigilance, accurate label reading, avoidance of nonaccidental exposure, prevention of cross-contamination, appropriate epinephrine administration, and education of all caretakers.

Section on allergy and immunology

Founded in 1948, the Section on Allergy and Immunology is dedicated to ensuring that children receive the highest quality of allergy and immunology care. To accomplish its mission, the Section provides a number of educational, training, and research programs and continually advocates for improved allergy and immunology care and services. The Section sponsors educational programs for both pediatric generalists and subspecialists at the American Academy of Pediatrics (AAP) National Conference and Exhibition (NCE) each fall and at the American Academy of Allergy Asthma & Immunology annual meeting each spring. The Section’s other educational endeavors include this annual “Best Articles Relevant to Pediatric Allergy and Immunology” supplement to Pediatrics, Visiting Professor Program, Pediatric Asthma Speaker’s Kit, online continuing medical education course on “asthma gadgets,” electronic quality improvement in practice program on asthma diagnosis and management (Education in Quality Improvement for Pediatric Practice [eQIPP], which meets the American Board of Pediatrics maintenance-ofcertification criteria), school nurse allergy tool kit, and a number of public education materials. The Section is also active in contributing to educational programs and resources such as AAP News, educational brochures, clinical reports, and many other endeavors. To support training and promote research in pediatric allergy and immunology, the Section awards travel grants to residents and training fellows to participate and present cases at the AAP NCE and provides outstanding abstract awards for training fellows and junior faculty for presentation at the American Academy of Allergy Asthma & Immunology annual meeting. In close collaboration with other subspecialty societies, the Section is actively involved with initiatives to improve subspecialty education such as the American Board of Allergy and Immunology maintenance-of-certification requirements. Section members represent the AAP in national and government conferences and provide input on federal legislation on behalf of the AAP. For more information on all AAP allergy and immunology resources and initiatives, visit www.aap.org/sections/allergy. The reviews contained in the 2011 synopsis were written by Fellows of the AAP Section on Allergy and Immunology and fellows in allergy and immunology training programs who contributed reviews with their mentors. The editor selected the journals to be reviewed on the basis of the likelihood that they would contain articles on allergy and immunology that would be of value and interest to the pediatrician. Each journal was assigned to a voluntary reviewer who was responsible for selecting articles and writing reviews of their articles. Only articles of original research were selected for review. Final selection of the articles to be included was made by the editor. The 2010–2011 journals chosen for review were Allergy, American Journal of Asthma & Allergy for Pediatricians, Archives of Pediatric and Adolescent Medicine, American Journal of Medicine, American Journal of Respiratory and Critical Care Medicine, Annals of Allergy, Asthma, and Immunology, Annals of Internal Medicine, Archives of Disease in Childhood, Archives of Internal Medicine, Blood, British Journal of Dermatology, British Medical Journal, Chest, Clinical and Experimental Allergy, Clinical Pharmacology and Therapeutics, Critical Care Medicine, European Journal of Pediatrics, European Respiratory Journal, Immunology, Journal of Allergy and Clinical Immunology, Journal of the American Academy of Dermatology, Journal of the American Medical Association, Journal of Applied Physiology, Journal of Experimental Medicine, Journal of Immunology, Journal of Infectious Diseases, Journal of Pediatric Gastroenterology and Nutrition, Journal of Pediatrics, Journal of Pharmacology and Experimental Therapeutics, Lancet, Nature, New England Journal of Medicine, Pediatrics, Medicine, Pediatric Allergy and Immunology, Pediatric Asthma, Allergy & Immunology, Pediatric Dermatology, Pediatric Infectious Disease Journal, and Science. The editor and the Section on Allergy and Immunology gratefully acknowledge the work of the reviewers and their trainees who assisted. The reviewers were Stuart L. Abramson, MD, PhD, Sugar Land, TX; James R. Banks, MD, Arnold, MD; Theresa A. Bingemann, MD, Rochester,

Rural health disparities in asthma care and outcomes

Fifty-nine million Americans (21% of the US population) live in rural areas of the United States. Compared with persons living in urban areas of the United States, rural populations have lower income, a higher rate of government versus private insurance, and decreased access to health care. Although there are reports of lower asthma prevalence in rural areas, the majority of these data have been published on international populations, with few available studies looking at American urban versus rural asthma prevalence on a national scale or comparing rural with nearby urban cohorts in the United States. A large body of literature, mainly generated from studies of rural Europe, suggests that lower prevalence might be due to beneficial effects of exposure to farm environments, but the extent to which this applies to the rural United States, where a smaller proportion of the population engages in farming, is unclear. The United States has the additional covariate of having a higher proportion of African Americans, who have a greater asthma burden than whites independent of socioeconomic status, clustered in cities. There are data indicating that rural patients have increased difficulty obtaining health care in general and limited data suggesting that they receive inferior care for asthma. Future work is needed to more clearly define asthma prevalence and morbidity among residents of the rural United States, as well as to identify interventions effective in this population.

A comparison of asthma prevalence and morbidity between rural and urban schoolchildren in Arkansas

BACKGROUND Asthma disproportionately affects minority and low-income children. Investigations that focus on high-risk pediatric populations outside the inner city are limited. OBJECTIVE To compare asthma prevalence and morbidity in urban and rural children in Arkansas. METHODS We administered a validated survey to parents of children enrolled in urban and rural school districts in Arkansas. Rates of asthma diagnosis, asthma symptoms, medication use, and health care utilization were compared between urban and rural groups. RESULTS Age and sex distributions were similar; however, 85% of rural and 67% of urban children were black and 78% of rural and 37% of urban children had state-issued medical insurance (P < .001 for both). Provider-diagnosed asthma was similar in the rural vs urban groups (19% vs 20%); however, rural children were more commonly diagnosed as having chronic bronchitis (7% vs. 2%, P < .001). Rural children had more asthma morbidity compared with urban children, including recurrent trouble breathing (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.5-2.2), recurrent cough (OR, 2.2; 95% CI, 1.9-2.6), recurrent chest tightness (OR, 1.8; 95% CI, 1.5-2.2), and repeated episodes of bronchitis (OR, 2.2; 95% CI, 1.7-2.8) during the preceding 2 years. Rural children were more likely to report symptoms consistent with moderate to severe asthma compared with urban children (46% vs. 35%, P < .001). There were no differences in health care utilization between groups. CONCLUSION Asthma prevalence was similar between representative rural and urban groups in Arkansas, but asthma morbidity was significantly higher in the rural group.

Mobile-based asthma action plans for adolescents

Abstract Purpose: To examine feasibility and utilization of a mobile asthma action plan (AAP) among adolescents. Methods: Adolescents (aged 12–17 years) with persistent asthma had their personalized AAP downloaded to a smartphone application. Teens were prompted by the mobile application to record either daily symptoms or peak flow measurements and to record medications. Once data were entered, the application provided immediate feedback based on the teen’s AAP instructions. Asthma Control Test (ACT®) and child asthma self-efficacy scores were examined pre- and post-intervention. Results: Adolescents utilized the mobile AAP a median 4.3 days/week. Participant satisfaction was high with 93% stating that they were better able to control asthma by utilizing the mobile AAP. For participants with uncontrolled asthma at baseline, median (interquartile range) ACT scores improved significantly from 16 (5) to 18 (8) [p = 0.03]. Median asthma attack prevention self-efficacy scores improved from 34 (3.5) to 36 (5.3) [p = 0.04]. Conclusions: Results suggest that personalized mobile-based AAPs are a feasible method to communicate AAP instructions to teens.

Novel baseline predictors of adverse events during oral immunotherapy in children with peanut allergy

Background: Though peanut oral immunotherapy (OIT) is a promising investigational therapy, its potential is limited by substantial adverse events (AEs), which are relatively understudied. Objective: A retrospective analysis was conducted, pooling data from 3 pediatric peanut OIT trials, comprising the largest analysis of peanut OIT safety to date. Methods: We pooled data from 104 children with peanut allergy from 3 peanut OIT studies. We catalogued AEs from parental reports, daily symptom diaries, and dose escalations. We included events that were considered likely related to OIT and identified potential baseline predictors of higher AE rates using generalized linear regression models. Results: Eighty percent of subjects experienced likely related AEs during OIT (72% during buildup and 47% during maintenance). Of these AEs, over 90% occurred while at home. Approximately 42% of subjects experienced systemic reactions, and 49% experienced gastrointestinal symptoms. Twenty percent of subjects dropped out, with half (10% of the overall group) due to persistent gastrointestinal symptoms. Baseline allergic rhinitis (AR) and peanut SPT wheal size were significant predictors of higher overall AE rates. SPT wheal size predicted increased gastrointestinal AEs, and AR predicted increased systemic reactions. Over the course of OIT, 61% of subjects received treatment for likely related AEs, 59% with antihistamines and 12% with epinephrine. Conclusions: Peanut OIT is associated with frequent AEs, with rates declining over time, and most graded mild. However, systemic reactions and intolerable gastrointestinal AEs do occur and are significantly associated with AR and peanut SPT wheal size, respectively. Further study is needed of predictive biomarkers and the overall risks and benefits of OIT.