The Natural History of Peanut and Egg Allergy and Predictors of Persistence: The Healthnuts Longitudinal Study, 6-Year-Old Follow-up

Immune response evolution in peanut epicutaneous immunotherapy for peanut-allergic children

BACKGROUND

Epicutaneous immunotherapy with investigational Viaskin™ Peanut 250 μg (DBV712) has demonstrated statistically superior desensitization versus placebo in peanut-allergic children in clinical trials. It is unclear whether serologic biomarkers predict response.

METHODS

Serum-specific IgG4 and IgE (whole peanut and components) from subjects enrolled in the phase 3 Efficacy and Safety of Viaskin Peanut in Children With IgE-Mediated Peanut Allergy study were examined by exploratory univariate and multivariate analyses to determine trajectories and predictors of treatment response, based upon peanut protein eliciting dose (ED) at Month (M) 12 double-blind placebo-controlled food challenge.

RESULTS

Among Viaskin Peanut-treated subjects, peanut sIgG4 significantly increased from baseline through M12 and peanut sIgE peaked at M3 and fell below baseline by M12, with sIgG4 and sIgE peanut components mirroring these trajectories. Placebo subjects had no significant changes. By univariate analysis, M12 peanut sIgG4/sIgE was higher in treatment responders (p < 0.001) and had highest area under the curve (AUC) for predicting ED ≥300 mg and ≥1000 mg (AUC 69.5% and 69.9%, respectively). M12 peanut sIgG4/sIgE >20.1 predicted M12 ED ≥300 mg (80% positive predictive value). The best performing component was Ara h 1 sIgE <15.7 kUA /L (AUC 66.5%). A multivariate model combining Ara h 1 and peanut sIgG4/sIgE had an AUC of 68.2% (ED ≥300 mg) and 67.8% (ED ≥1000 mg).

CONCLUSIONS

Peanut sIgG4 rise most clearly differentiated Viaskin Peanut versus placebo subjects. sIgG4/sIgE ratios >20.1 and the combination of Ara h 1 and peanut sIgG4/sIgE had moderate ability to predict treatment response and could potentially be useful for clinical monitoring. Additional data are needed to confirm these relationships.

The Cost-Effectiveness of Preschool Peanut Oral Immunotherapy in the Real-World Setting

BACKGROUND

Across North America, 1.4% to 4.5% of children and families live with peanut allergy (PA). Preschool peanut oral immunotherapy (POIT) has been shown to be safe and effective in the real-world setting.

OBJECTIVE

Evaluate the cost effectiveness of preschool POIT in North America.

METHODS

Markov cohort analyses and microsimulation was used to evaluate simulated preschool children with PA over an 80-year time horizon. Models incorporated the natural history of PA, comparing children treated with preschool POIT with those not receiving immunotherapy. Costs were expressed in U.S. and Canadian dollars.

RESULTS

A preschool POIT strategy was associated with cost savings while improving quality-adjusted life-years (QALY), dominating a nonimmunotherapy approach. Over the model horizon, when all costs (and effectiveness) of PA were included from a societal perspective, a POIT versus a non-POIT approach cost $82,514 (18.51 QALY) versus $84,367 (17.75 QALY) in the United States, and $40,111 (18.83 QALY) versus $53,848 (18.26 QALY) in Canada. In microsimulations, systemic reactions to POIT were less frequent than anaphylaxis from accidental exposure without POIT (United States: 3.59, SD 3.49 vs 19.53, SD 11.71; Canada: 3.63, SD 3.54 vs 4.56, SD 3.30), epinephrine use was reduced with POIT (United States: 5.85, SD 5.73 vs 9.76, SD 5.85; Canada: 0.34, SD 0.36 vs 0.53, SD 0.38), and fatalities were rare but lower in the POIT strategy (United States: 0.00005, SD 0.0071 vs 0.00015, SD 0.012; Canada: 0.00005, SD 0.0071 vs 0.00009, SD 0.0095).

CONCLUSIONS

Preschool POIT in a real-world setting improved health and economic outcomes in the United States and Canada.

Peanut allergy diagnosis: A 2020 practice parameter update, systematic review, and GRADE analysis

Given the burden of disease and the consequences of a diagnosis of peanut allergy, it is important that peanut allergy be accurately diagnosed so that an appropriate treatment plan can be developed. However, a test that indicates there is peanut sensitization present (eg, a "positive" test) is not always associated with clinical reactivity. This practice parameter addresses the diagnosis of IgE-mediated peanut allergy, both in children and adults, as pertaining to 3 fundamental questions, and based on the systematic reviews and meta-analyses, makes recommendations for the clinician who is evaluating a patient for peanut allergy. These questions relate to when diagnostic tests should be completed, which diagnostic tests to utilize, and the utility (or lack thereof) of diagnostic testing to predict the severity of a future allergic reaction to peanut.

An update on international practice variation in peanut introduction: conundrums, controversies, and a new direction

PURPOSE OF REVIEW

Introduction of peanut during the first year of life is associated with an 81% relative risk reduction of developing peanut allergy in infants with severe eczema, egg allergy, or both. However, significant international variation exists in risk stratification prior to peanut introduction.

RECENT FINDINGS

A policy-level screening approach, such as the one in the United States, is not practical and is associated with higher costs and more cases of peanut allergy over time, in contrast to international models that recommend universal early introduction without prescreening. In Australia, population-level efforts to introduce peanut early without screening have demonstrated high rates of peanut introduction before 12 months of age and low rates of severe allergic reactions. In contrast, screening prior to peanut introduction in the United States is associated with 'screening creep' - the tendency of clinicians to test populations where screening is not recommended.

SUMMARY

Early peanut introduction can reduce the risk of developing food allergy and is more effective without a risk-based screening approach. In some circumstances, shared clinical decision-making can facilitate food allergy prevention in a manner consistent with family values and preferences.

Mass cytometry reveals cellular fingerprint associated with IgE+ peanut tolerance and allergy in early life

IgE-mediated peanut allergic is common, often serious, and usually lifelong. Not all individuals who produce peanut-specific IgE will react upon consumption of peanut and can eat the food without adverse reactions, known as sensitized tolerance. Here, we employ high-dimensional mass cytometry to define the circulating immune cell signatures associated with sensitized tolerance and clinical allergy to peanut in the first year of life. Key features of clinical peanut allergic are increased frequency of activated B cells (CD19^hiHLADR^hi), overproduction of TNFα and increased frequency of peanut-specific memory CD4 T cells. Infants with sensitized tolerance display reduced frequency but hyper-responsive naive CD4 T cells and an increased frequency of plasmacytoid dendritic cells. This work demonstrates the utility and power of high-dimensional mass cytometry analysis to interrogate the cellular interactions that are associated with allergic sensitization and clinical food allergy in the first year of life.

Commercial claims costs related to health care resource use associated with a diagnosis of peanut allergy

BACKGROUND

Peanut allergy (PA) affects approximately 1.6 million US children. The current standard of care is strict avoidance and prompt reaction treatment. Peanut allergy health care costs and health care resource utilization (HCRU) are poorly understood.

OBJECTIVE

To estimate PA health care costs and HCRU using a nationally representative commercial payer database.

METHODS

The IBM MarketScan Commercial Claims and Encounters Database was examined for PA diagnosis/reaction codes between January 2010 and October 2016 in patients 64 years of age or younger, with age cohort-matched controls. Outcomes were measured 12 months before and after the first claim date. Health care costs and HCRU were compared using Student's t tests and χ² tests.

RESULTS

Patients with a PA-related diagnostic code (n = 41,675) incurred almost double all-cause health care costs vs controls ($6436 vs $3493, P < .001), mainly from inpatient and outpatient medical costs ($5002 vs $2832, P < .001). More than one third of the PA group patients (36%) had a code indicative of an anaphylactic reaction during follow-up. Mean PA or reaction-related code costs per visit totaled $7921 for hospitalizations and $1115 for emergency department (ED) visits. Costs were 30% lower in patients with asthma codes without PA codes vs those with both codes ($5678 vs $8112, P < .001); all-cause ED costs were more than double in patients with atopic dermatitis codes with PA codes vs those without PA codes ($654 vs $308, P < .001).

CONCLUSION

National commercial payer claims data indicate a significant health care burden associated with a PA-related code, including over $6400/patient in annual all-cause costs and increased health care utilization.