Safety, clinical, and immunologic efficacy of a Chinese herbal medicine (Food Allergy Herbal Formula-2) for food allergy

BACKGROUND

Food Allergy Herbal Formula-2 (FAHF-2) is a 9-herb formula based on traditional Chinese medicine that blocks peanut-induced anaphylaxis in a murine model. In phase I studies FAHF-2 was found to be safe and well tolerated.

OBJECTIVE

We sought to evaluate the safety and effectiveness of FAHF-2 as a treatment for food allergy.

METHODS

In this double-blind, randomized, placebo-controlled study 68 subjects aged 12 to 45 years with allergies to peanut, tree nut, sesame, fish, and/or shellfish, which were confirmed by baseline double-blind, placebo-controlled oral food challenges (DBPCFCs), received FAHF-2 (n = 46) or placebo (n = 22). After 6 months of therapy, subjects underwent DBPCFCs. For those who demonstrated increases in the eliciting dose, a repeat DBPCFC was performed 3 months after stopping therapy.

RESULTS

Treatment was well tolerated, with no serious adverse events. By using intent-to-treat analysis, the placebo group had a higher eliciting dose and cumulative dose (P = .05) at the end-of-treatment DBPCFC. There was no difference in the requirement for epinephrine to treat reactions (P = .55). There were no significant differences in allergen-specific IgE and IgG4 levels, cytokine production by PBMCs, or basophil activation between the active and placebo groups. In vitro immunologic studies performed on subjects' baseline PBMCs incubated with FAHF-2 and food allergen produced significantly less IL-5, greater IL-10 levels, and increased numbers of regulatory T cells than untreated cells. Notably, 44% of subjects had poor drug adherence for at least one third of the study period.

CONCLUSION

FAHF-2 is a safe herbal medication for subjects with food allergy and shows favorable in vitro immunomodulatory effects; however, efficacy for improving tolerance to food allergens is not demonstrated at the dose and duration used.

Correlations between basophil activation, allergen-specific IgE with outcome and severity of oral food challenges

BACKGROUND

Double-blinded, placebo-controlled food challenges (DBPCFCs) remain the gold standard for diagnosing food allergies. Skin prick tests (SPTs) and allergen-specific IgE (sIgE) are routinely used in medical practice but are not sufficient to predict severity of clinical reactivity.

OBJECTIVE

To compare the utility of SPT wheal diameter, sIgE, allergen-specific IgG4 (sIgG4), total IgE (tIgE), sIgE/sIgG4 and sIgE/tIgE ratios, peanut component-specific IgE, and basophil activation in predicting outcome and severity of reactions at DBPCFCs.

METHODS

Sixty-seven subjects (12-45 years old) underwent DBPCFCs for peanut, tree nut, fish, shrimp, and/or sesame as part of screening for enrollment in a clinical trial. The SPT, sIgE, tIgE, sIgG4, and peanut component-specific IgE (if applicable) levels were measured. CD63 upregulation on basophils in response to in vitro allergen challenge was analyzed by flow cytometry. Correlations between these measurements and DBPCFC severity scores were analyzed.

RESULTS

The SPT and sIgE showed a weak correlation with DBPCFC severity scores, but tIgE and sIgG4 did not. The sIgE/sIgG4 ratio differentiated between positive and negative reactions but did not correlate with DBPCFC severity scores. A low positive correlation was seen between DBPCFC severity score and Ara h 2 IgE, whereas a low negative correlation with Ara h 8 IgE was observed. Basophil activation was positively correlated with DBPCFC severity scores. Receiver operating characteristic curves showed basophil reactivity had the largest area under the curve at 0.904 and sIgE at 0.870.

CONCLUSION

These results indicate that basophil activation testing can enhance discrimination between allergic and nonallergic individuals and could serve as an additional tool to predict clinical severity.

Peanut and tree nut allergy

Allergy to peanut and tree nuts is a major worldwide health concern. The prevalence of these allergies may be increasing, but the reasons for these increases remain unclear. This group of foods accounts for a large proportion of severe and fatal food-allergic reactions. These allergies present most often during childhood but can occur at any age. Resolution is possible but uncommon, and frequent lifetime reactions caused by accidental ingestion are a serious problem. The major allergens of peanut and most tree nuts have been identified, allowing for insights into patient diagnoses, clinical outcomes, and potential future immunotherapies.

Sublingual immunotherapy for peanut allergy: Long-term follow-up of a randomized multicenter trial

BACKGROUND

We previously reported the initial results of the first multicenter, randomized, double-blind, placebo-controlled clinical trial of peanut sublingual immunotherapy (SLIT), observing a favorable safety profile associated with modest clinical and immunologic effects in the first year.

OBJECTIVE

We sought to provide long-term (3-year) clinical and immunologic outcomes for our peanut SLIT trial. Key end points were (1) percentage of responders at 2 years (ie, could consume 5 g of peanut powder or a 10-fold increase from baseline), (2) percentage reaching desensitization at 3 years, (3) percentage attaining sustained unresponsiveness after 3 years, (4) immunologic end points, and (5) assessment of safety parameters.

METHODS

Response to treatment was evaluated in 40 subjects aged 12 to 40 years by performing a 10-g peanut powder oral food challenge after 2 and 3 years of daily peanut SLIT therapy. At 3 years, SLIT was discontinued for 8 weeks, followed by another 10-g oral food challenge and an open feeding of peanut butter to assess sustained unresponsiveness.

RESULTS

Approximately 98% of the 18,165 doses were tolerated without adverse reactions beyond the oropharynx, with no severe symptoms or uses of epinephrine. A high rate (>50%) discontinued therapy. By study's end, 4 (10.8%) of 37 SLIT-treated participants were fully desensitized to 10 g of peanut powder, and all 4 achieved sustained unresponsiveness. Responders at 2 years showed a significant decrease in peanut-specific basophil activation and skin prick test titration compared with nonresponders.

CONCLUSIONS

Peanut SLIT induced a modest level of desensitization, decreased immunologic activity over 3 years in responders, and had an excellent long-term safety profile. However, most patients discontinued therapy by the end of year 3, and only 10.8% of subjects achieved sustained unresponsiveness.

Advances in allergic skin disease, anaphylaxis, and hypersensitivity reactions to foods, drugs, and insects in 2014

This review highlights some of the research advances in anaphylaxis; hypersensitivity reactions to foods, drugs, and insects; and allergic skin diseases that were reported in the Journal in 2014. Studies on food allergy suggest worrisomely high rates of peanut allergy and food-induced anaphylaxis-related hospitalizations. Evidence is mounting to support the theory that environmental exposure to peanut, such as in house dust, especially with an impaired skin barrier attributed to atopic dermatitis (AD) and loss of function mutations in the filaggrin gene, is a risk factor for sensitization and allergy. Diagnostic tests are improving, with early studies suggesting the possibility of developing novel cellular tests with increased diagnostic utility. Treatment trials continue to show the promise and limitations of oral immunotherapy, and mechanistic studies are elucidating pathways that might define the degree of efficacy of this treatment. Studies have also provided insights into the prevalence and characteristics of anaphylaxis and insect venom allergy, such as suggesting that baseline platelet-activating factor acetylhydrolase activity levels are related to the severity of reactions. Advances in drug allergy include identification of HLA associations for penicillin allergy and a microRNA biomarker/mechanism for toxic epidermal necrolysis. Research identifying critical events leading to skin barrier dysfunction and the polarized immune pathways that drive AD have led to new therapeutic approaches in the prevention and management of AD.

Mental health and quality-of-life concerns related to the burden of food allergy

As food allergy increases, more research is devoted to its influence on patient and family mental health and quality of life (QoL). This article discusses the effects on parent and child QoL, as well as distress, while appraising the limitations of knowledge given the methods used. Topics include whether QoL and distress are affected compared with other illnesses, assessment of distress and QoL in parents compared with children, concerns about food allergy-related bullying, and the necessity for evidence-based interventions. Suggestions are offered for how to improve QoL and reduce distress on the way to better coping with food allergy.

Optimizing the diagnosis of food allergy

Accurately diagnosing a patient with a possible food allergy is important to avoid unnecessary dietary restrictions and prevent life-threatening reactions. Routine testing modalities have limited accuracy, and an oral food challenge is often required to make a definitive diagnosis. Given that they are labor intensive and risk inducing an allergic reaction, several alternative diagnostic modalities have been investigated. Testing for IgE antibodies to particular protein components in foods has shown promise to improve diagnostics and has entered clinical practice. Additional modalities show potential, including epitope binding, T-cell studies, and basophil activation.

The role of casein-specific IgA and TGF-β in children with food protein-induced enterocolitis syndrome to milk

BACKGROUND

Food protein-induced enterocolitis syndrome (FPIES) is a gastrointestinal hypersensitivity disorder with a poorly understood pathophysiology and no biomarkers to aid in diagnosis.

OBJECTIVE

To investigate humoral and cellular responses to casein in children with milk-FPIES, including the role of casein-specific (cs) IgA and T-cell mediated TGF-β responses.

PATIENTS AND METHODS

Thirty-one children previously diagnosed with milk-FPIES were challenged with milk. Twelve age-matched children with FPIES to other foods and 6 milk-tolerant children without a history of FPIES were used as controls. Casein-specific IgE, IgG, IgG4, and IgA were measured in serum and TGF-β levels in supernatants of casein-stimulated PBMCs.

RESULT

Twenty-six children with milk-FPIES reacted (active milk-FPIES) and five tolerated milk (milk-FPIES resolved) during food challenge. All of them had significantly lower levels of csIgG, csIgG4, and csIgA than control children (p-value<0.001). There were no TGF-β responses in supernatants of active milk-FPIES children.

CONCLUSION

Children with milk-FPIES have low levels of csIgG, csIgG4, and csIgA. In particular, children with active FPIES to cow's milk have deficient T-cell mediated TGF-β responses to casein, rendering TGF-β a promising biomarker in identifying children who are likely to experience FPIES reactions to this allergen. Prospective studies are needed to validate these findings, elucidate their role in FPIES pathophysiology, and establish the diagnostic utility of TGF-β in milk-induced FPIES.

Food allergy: a practice parameter update-2014

This parameter was developed by the Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma & Immunology (JCAAI). The AAAAI and the ACAAI have jointly accepted responsibility for establishing "Food Allergy: A practice parameter update-2014." This is a complete and comprehensive document at the current time. The medical environment is a changing one, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single individual, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, ACAAI, and JCAAI. These parameters are not designed for use by pharmaceutical companies in drug promotion.

Utilizing physician screening questions for detecting anxiety among food-allergic pediatric patients

OBJECTIVE

To explore the utility of clinician screening for anxiety in pediatric food-allergic patients.

STUDY DESIGN

In Phase I, 39 patients completed an anxiety questionnaire while their allergists completed a companion questionnaire estimating their patient's responses. Allergists then attended an educational workshop to improve their anxiety detection. In Phase II, following the workshop, questionnaires were completed by an additional 39 patients and their allergists.

RESULTS

The percentage of clinician questionnaires with a "do not know" response decreased from 70% to 5% after the workshop. Correlation between allergists' and children's responses remained nonsignificant (r = .314, P = .321) before the workshop and after (r = .303, P = .068) and only 25% of patients who reported elevated anxiety were identified. Additionally, clinicians expressed poor acceptability of the screening.

CONCLUSIONS

After the workshop, clinicians did not more accurately detect anxiety and found the process intrusive. Alternative methods for uncovering anxiety among high-risk patients are needed.

Clinical features and resolution of food protein-induced enterocolitis syndrome: 10-year experience

BACKGROUND

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated food allergy. FPIES diagnosis is frequently delayed because of the absence of classic allergic symptoms and lack of biomarkers.

OBJECTIVE

We sought to characterize the clinical features and resolution of FPIES in patients evaluated in our practice.

METHODS

Subjects 6 months to 45 years of age with FPIES were prospectively recruited for oral food challenges (OFCs). Medical records were searched to identify the subjects who did not participate in OFCs.

RESULTS

Among 160 subjects, 54% were male; median age at diagnosis was 15 months. We performed 180 OFCs to 15 foods in 82 subjects; 30% of the study population had FPIES confirmed based on OFC results. The most common foods were cow's milk (44%), soy (41%), rice (22.5%), and oat (16%). The majority (65%) reacted to 1 food, 26% reacted to 2 foods, and 9% reacted to 3 or more foods. The majority were atopic, and 39% had IgE sensitization to another food. Thirty-nine (24%) subjects had positive specific IgE levels to the food inducing FPIES. Among children with specific IgE to cow's milk, 41% changed from a milk FPIES to an IgE-mediated phenotype over time. The median age when tolerance was established was 4.7 years for rice, 4 years for oat, and 6.7 years for soy. Median age when milk tolerance was established for subjects with undetectable milk-specific IgE levels was 5.1 years, whereas none of the subjects with detectable milk-specific IgE became tolerant to milk during the study (P = .003).

CONCLUSION

FPIES typically resolves by age 5 years. Milk FPIES, especially with detectable food-specific IgE, can have a protracted course and eventually transition to acute reactions.

Creation and validation of web-based food allergy audiovisual educational materials for caregivers

Studies reveal deficits in caregivers' ability to prevent and treat food-allergic reactions with epinephrine and a consumer preference for validated educational materials in audiovisual formats. This study was designed to create brief, validated educational videos on food allergen avoidance and emergency management of anaphylaxis for caregivers of children with food allergy. The study used a stepwise iterative process including creation of a needs assessment survey consisting of 25 queries administered to caregivers and food allergy experts to identify curriculum content. Preliminary videos were drafted, reviewed, and revised based on knowledge and satisfaction surveys given to another cohort of caregivers and health care professionals. The final materials were tested for validation of their educational impact and user satisfaction using pre- and postknowledge tests and satisfaction surveys administered to a convenience sample of 50 caretakers who had not participated in the development stages. The needs assessment identified topics of importance including treatment of allergic reactions and food allergen avoidance. Caregivers in the final validation included mothers (76%), fathers (22%), and other caregivers (2%). Race/ethnicity were white (66%), black (12%), Asian (12%), Hispanic (8%), and other (2%). Knowledge tests (maximum score = 18) increased from a mean score of 12.4 preprogram to 16.7 postprogram (p < 0.0001). On a 7-point Likert scale, all satisfaction categories remained above a favorable mean score of 6, indicating participants were overall very satisfied, learned a lot, and found the materials to be informative, straightforward, helpful, and interesting. This web-based audiovisual curriculum on food allergy improved knowledge scores and was well received.