Allergen-specific oral immunotherapy for peanut allergy (Review)

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Allergen-specific oral immunotherapy for peanut allergy

(Review)

Nurmatov U, Venderbosch I, Devereux G, Simons FER, Sheikh A

This is a reprint of a Cochrane review, prepared and maintained by The Cochrane Collaboration and published inThe Cochrane Library 2012, Issue 9

http://www.thecochranelibrary.com

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T A B L E O F C O N T E N T S 1 HEADER . . . . 1 ABSTRACT . . . . 2

PLAIN LANGUAGE SUMMARY . . . .

3 BACKGROUND . . . . 4 OBJECTIVES . . . . 4 METHODS . . . . 6 RESULTS . . . . 8 DISCUSSION . . . . 9 AUTHORS’ CONCLUSIONS . . . . 9 ACKNOWLEDGEMENTS . . . . 9 REFERENCES . . . . 12 CHARACTERISTICS OF STUDIES . . . . 20 DATA AND ANALYSES . . . .

20 ADDITIONAL TABLES . . . . 20 APPENDICES . . . . Figure 1. . . 23 23 HISTORY . . . . 23 CONTRIBUTIONS OF AUTHORS . . . . 23 DECLARATIONS OF INTEREST . . . . 24 SOURCES OF SUPPORT . . . . 24

DIFFERENCES BETWEEN PROTOCOL AND REVIEW . . . .

24

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[Intervention Review]

Allergen-specific oral immunotherapy for peanut allergy

Ulugbek Nurmatov1, Iris Venderbosch2, Graham Devereux3, F Estelle R Simons4, Aziz Sheikh5

1Allergy & Respiratory Research Group, Centre for Population Health Sciences, The University of Edinburgh, Edinburgh, UK. 2Radboud University Nijmegen Medical Center, Nijmegen, Netherlands.3Department of Child Health, Royal Aberdeen Children’s Hospital, The University of Aberdeen, Aberdeen, UK.4Department of Pediatrics & Child Health; Department of Immunology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.5Centre for Population Health Sciences, The University of Edinburgh, Edinburgh, UK

Contact address: Aziz Sheikh, Centre for Population Health Sciences, The University of Edinburgh, Medical School, Doorway 3, Teviot Place, Edinburgh, EH8 9AG, UK.Aziz.Sheikh@ed.ac.uk.

Editorial group:Cochrane Tobacco Addiction Group.

Publication status and date:New, published in Issue 9, 2012.

Review content assessed as up-to-date: 13 April 2012.

Citation: Nurmatov U, Venderbosch I, Devereux G, Simons FER, Sheikh A. Allergen-specific oral immunotherapy for peanut allergy. Cochrane Database of Systematic Reviews2012, Issue 9. Art. No.: CD009014. DOI: 10.1002/14651858.CD009014.pub2.

Copyright © 2012 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.

A B S T R A C T Background

Peanut allergy is one of the most common forms of food allergy encountered in clinical practice. In most cases, it does not spontaneously resolve; furthermore, it is frequently implicated in acute life-threatening reactions. The current management of peanut allergy centres on meticulous avoidance of peanuts and peanut-containing foods. Allergen-specific oral immunotherapy (OIT) for peanut allergy aims to induce desensitisation and then tolerance to peanut, and has the potential to revolutionise the management of peanut allergy. However, at present there is still considerable uncertainty about the effectiveness and safety of this approach.

Objectives

To establish the effectiveness and safety of OIT in people with IgE-mediated peanut allergy who develop symptoms after peanut ingestion.

Search methods

We searched in the following databases: AMED, BIOSIS, CAB, CINAHL,The Cochrane Library, EMBASE, Global Health, Google Scholar, IndMed, ISI Web of Science, LILACS, MEDLINE, PakMediNet and TRIP. We also searched registers of on-going and unpublished trials. The date of the most recent search was January 2012.

Selection criteria

Randomised controlled trials (RCTs), quasi-RCTs or controlled clinical trials involving children or adults with clinical features indicative of IgE-mediated peanut allergy treated with allergen-specific OIT, compared with control group receiving either placebo or no treatment, were eligible for inclusion.

Data collection and analysis

Two review authors independently checked and reviewed titles and abstracts of identified studies and assessed risk of bias. The full text of potentially relevant trials was assessed. Data extraction was independently performed by two reviewers with disagreements resolved through discussion.

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Main results

We found one small RCT, judged to be at low risk of bias, that enrolled 28 children aged 1 to 16 years with evidence of sensitisation to peanut and a clinical history of reaction to peanut within 60 minutes of exposure. The study did not include children who had moderate to severe asthma or who had a history of severe peanut anaphylaxis. Randomisation was in a 2:1 ratio resulting in 19 children being randomised to the intervention arm and nine to the placebo arm. Intervention arm children received OIT with peanut flour and control arm participants received placebo comprising of oat flour. The primary outcome was assessed using a double-blind, placebo controlled oral food challenge (OFC) at approximately one year. No data were available on longer term outcomes beyond the OFC conducted at the end of the study.

Because of adverse events, three patients withdrew from the intervention arm before the completion of the study. Therefore, only 16 participants received the full course of peanut OIT, whereas all nine patients receiving placebo completed the trial. The per-protocol analysis found a significant increase in the threshold dose of peanut allergen required to trigger a reaction in those in the intervention arm with all 16 participants able to ingest the maximum cumulative dose of 5000 mg of peanut protein (which the authors equate as being equivalent to approximately 20 peanuts) without developing symptoms, whereas in the placebo group they were able to ingest a median cumulative dose of 280 mg (range: 0 to 1900 mg, P < 0.001) before experiencing symptoms. Per-protocol analyses also demonstrated that peanut OIT resulted in reductions in skin prick test size (P < 0.001), interleukin-5 (P = 0.01), interleukin-13 (P = 0.02) and an increase in peanut-specific immunoglobulin G4(IgG4) (P < 0.01).

Children in the intervention arm experienced more adverse events during treatment than those in the placebo arm. In the initial day escalation phase, nine (47%) of the 19 participants initially enrolled in the OIT arm experienced clinically-relevant adverse events which required treatment with H1-antihistamines, two of which required additional treatment with epinephrine (adrenaline). Authors’ conclusions

The one small RCT we found showed that allergen-specific peanut OIT can result in desensitisation in children, and that this is associated with evidence of underlying immune-modulation. However, this treatment approach was associated with a substantial risk of adverse events, although the majority of these were mild. In view of the risk of adverse events and the lack of evidence of long-term benefits, allergen-specific peanut OIT cannot currently be recommended as a treatment for the management of patients with IgE-mediated peanut allergy. Larger RCTs are needed to investigate the acceptability, long-term effectiveness and cost-effectiveness of safer treatment regimens, particularly in relation to the induction of clinical and immunological tolerance.

P L A I N L A N G U A G E S U M M A R Y Oral immunotherapy for the treatment of peanut allergy

Allergy to peanut can result in potentially life-threatening reactions and, on occasions, death. Unlike many other forms of food allergy, allergy to peanut is typically life-long. There is currently no cure for peanut allergy and people with this allergy must constantly be careful to avoid accidentally eating peanut or peanut-containing foods. If a person with a peanut allergy accidentally ingests peanut, he or she may develop serious allergic reactions necessitating emergency treatment with epinephrine (adrenaline).

The overall goal of allergen-specific oral immunotherapy (OIT) for peanut allergy is to reduce and, if possible, eliminate the risk of further reactions associated with exposure to peanuts. Most people who have reactions to peanut have an immediate type (also sometimes known as IgE-mediated) reaction in which symptoms typically develop within minutes of exposure to peanut protein and it is for this group that allergen-specific OIT is a potential treatment approach. It is not considered suitable for those who experience more delayed (also sometimes known as non-IgE mediated) reactions. Treatment involves giving people with peanut allergy very small doses of peanut protein by mouth and gradually increasing the amount being administered (the build-up phase). Once the desired dose has been achieved, this is followed by the patient taking the same dose of peanut every day for a set period of time (maintenance phase). As giving doses of peanut to someone with a peanut allergy has the potential to introduce allergic reactions, participants’ safety needs to be carefully monitored during studies of peanut OIT.

We found one small trial undertaken in 28 children aged 1 to 16 years with confirmed peanut allergy. The study did not include children who had moderate to severe asthma or who had had severe anaphylaxis (a severe allergic reaction that may result in death) because of their peanut allergy. The authors randomised children to intervention or placebo in a 2:1 ratio. Intervention arm children received peanut flour whereas control arm participants received oat flour. The 48-week trial showed that treatment with peanut OIT enabled children receiving OIT to substantially increase the amount of peanut flour they ate in comparison with those in the placebo arm

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without having an allergic reaction. However, almost half of the children (nine out of 19) receiving OIT had an allergic reaction due to the OIT which required antihistamines, and two had more serious reactions to the treatment which required adrenaline (epinephrine). Although promising, based on the findings of this one small trial, we cannot recommend that peanut OIT be used routinely for people with peanut allergy. There is a need for further larger studies investigating safer OIT regimens and establishing the long-term effectiveness of OIT after treatment is stopped.

B A C K G R O U N D

Description of the condition

Peanut allergy is one of the most common food allergies in west-ernised countries affecting, for example, up to 1.8% of young children in the United Kingdom (Hourihane 2007) and approx-imately 1% of children and 0.6% of adults in North America (Sicherer 2010b). The prevalence of challenge-proven peanut al-lergy was 3.0% in Australian infants (Osborne 2011). The preva-lence of peanut allergy may (Mullins 2009;Sicherer 2010a) or may not (Ben-Shoshan 2009;Kotz 2011) be increasing. Of the eight major allergenic proteins in peanut, the components Ara h1 and Ara h2 (particularly the latter) are the most impor-tant predictors of clinical symptoms on exposure (de Leon 2007;

Nicolaou 2010).

IgE antibody-mediated allergic reactions to peanut involve specific sensitisation of tissue mast cells and blood basophils by the binding of IgE to the high-affinity IgE receptors on these cells. On re-exposure, peanut proteins bind to the IgE antibody specific to them and this triggers the release of histamine, tryptase and a variety of other inflammatory mediators (Burks 2008). Symptoms of an acute allergic reaction typically develop within minutes to a few hours after peanut ingestion. Severity is unpredictable and ranges from mild skin symptoms (e.g. hives, flushing), gastrointestinal symptoms (e.g. vomiting, abdominal pain, diarrhoea), to severe or fatal anaphylaxis involving obstruction of the upper or lower airways and respiratory distress and/or cardiovascular collapse (

Burks 2008;Simons 2011;Soar 2008).

There is currently no disease-modifying treatment or cure for peanut allergy (Sheikh 2010). Current management involves strict avoidance of peanut in all forms, including the minute quan-tities present in many packaged foods, as well as more obvious sources such as desserts, cookies and candies. Accidental expo-sures occur annually in more than 15% of patients at risk (Clark 2008;Yu 2006). The quality of life of affected people and their caregivers can be substantially reduced due to fear of incorrect food choices, ingestion of food containing hidden allergens, and the ever-present threat of anaphylaxis (Akeson 2007;King 2009;

Cummings 2010).

Pharmacological treatment of peanut allergy involves teaching patients and caregivers to recognise symptoms of anaphylaxis (Gallagher 2011), to promptly use an epinephrine (adrenaline) auto-injector, and to activate emergency medical services (Simons 2009).

Clinical peanut allergy is typically life-long (Sicherer 2007). Ther-apeutic interventions that provide permanent protection against unintentional peanut ingestion are therefore needed. Two decades ago, placebo-controlled trials of subcutaneous immunotherapy in patients with clinical peanut allergy showed promising re-sults, but there was an unacceptably high rate of adverse events (Oppenheimer 1992;Nelson 1997). Peanut oral immunotherapy (OIT) has been studied recently in patients with clinical peanut allergy, building on an approach successfully used more than a cen-tury ago to desensitise a child with egg allergy (Schofield 1908). In peanut OIT, incremental doses of peanut protein are admin-istered to carefully selected patients in physician-monitored, con-trolled clinical settings. Up-dosing in such settings is interspersed with periods of maintenance dosing at home (Burks 2008;Sicherer 2010b). The initial aim however is to provide clinical desensitisa-tion - i.e. to increase the threshold dose of exposure to peanut, and reduce the risk of allergic reactions from unintentional ingestion of peanut. The ultimate aim is to produce clinical and immuno-logic tolerance through down-regulation of the Th2 response to peanut that will endure irrespective of whether a previously clini-cally reactive patient continues to eat peanut on a regular basis or does not eat peanut at all (Clark 2009;Jones 2009).

There are different types/regimens of OIT protocols (e.g. rush, slow). In peanut OIT, peanut allergen can be delivered in a range of forms (e.g. crushed roasted peanuts, peanut flour and whole peanut kernels) and is swallowed thereby facilitating contact of the allergen with the gastro-intestinal mucosa.

Three non-randomised open studies of peanut OIT have been published to-date (Blumchen 2010;Clark 2009;Jones 2009) and the findings from these have been synthesised in an earlier system-atic review (Sheikh 2012). Although at inherently high risk of bias, these studies suggested that peanut OIT may achieve desensitisa-tion. For example, in one study, peanut OIT resulted in clinical desensitisation (defined as the ability to tolerate 3.9 g of peanut protein during an oral food challenge) for 27 of the 29 children

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who completed at least eight months of treatment. Down-regula-tion of the Th2 response to peanut was also documented: by 6 to 12 months, the size of the peanut skin prick test (SPT) decreased, basophil activation by peanut decreased, and cytokine production from peripheral blood mononuclear cells stimulated with peanut was modulated and by 12 to 18 months, peanut specific IgE de-creased and peanut specific IgG4 inde-creased (Jones 2009). These studies also demonstrated the high risk of adverse events associated with OIT.

Randomised, double-blind, placebo-controlled studies of peanut OIT are now ongoing. Important questions that need to be ad-dressed before such an approach can be considered for routine clin-ical use include issues to do with the effectiveness and cost-effec-tiveness of OIT and the need to better appreciate the risks associ-ated with treatment and how these can be minimised (Thyagarajan 2010).

Description of the intervention

As early as 1908, Schofield’s case report suggested that OIT can lead to desensitisation in those with egg allergy (Schofield 1908). Over the last hundred years, there has been considerable use of immunotherapy, but the majority of this relates to the manage-ment of people with allergic rhinitis who have pollen and other inhalant allergies. It is typically delivered through the subcu-taneous route and, more recently, by sublingual administration (Calderon 2011a;Calderon 2011b;Radulovic 2010). Two decades ago, small placebo-controlled trials of subcutaneous immunother-apy in peanut allergy were undertaken. Although the results were in some respects promising, the frequency of adverse events was high (Oppenheimer 1992;Nelson 1997). OIT is now being in-vestigated as an effective safer mode of immunotherapy in people with peanut allergy.

Recent studies using oral (and sublingual) immunotherapy appear to be promising. OIT is in particular of considerable interest as a possible treatment for peanut allergy (Sheikh 2010). The aim of treatment is initially to desensitise patients to peanut allergen, which by increasing the threshold dose of exposure, reduces the risk of reactions resulting from accidental ingestion whilst on treat-ment (Burks 2008). The ultimate aim is to induce a state of cure or tolerance, i.e. following the completion of OIT, allowing peo-ple to eat peanut whenever they want and in whatever quantity they want without developing symptoms. There is early evidence that OIT can induce significant longer-term humoral and cellular changes, which are suggestive of the development of immunolog-ical tolerance (Clark 2009;Jones 2009).

How the intervention might work

OIT involves the administration of initially very small doses (usu-ally micro or milligrams) of food allergen to food-allergic patients

in a controlled clinical setting. The dose of the administered food allergen is then systematically increased until a maximum toler-ated dose of food allergen is achieved (Jones 2009). Regular dos-ing with this maximal dose is then maintained at home by the patient. Successful desensitisation is thought to induce immuno-logical tolerance by generating allergen specific IL-10 secreting Tr1 and/or TGF-secreting Th3 regulatory T-cells (Sicherer 2006;

Moneret-Vautrin 2011). OIT is intended for patients with IgE-mediated peanut allergy. Mechanisms of non-IgE IgE-mediated food allergy are less well understood and currently OIT is not an ap-propriate form of treatment for non-IgE mediated disease.

Why it is important to do this review

OIT is a treatment approach that has the potential to revolutionise the management of people with peanut allergy. However, at present there is still considerable uncertainty about the effectiveness and safety of this approach (Sheikh 2010). There is therefore a need to systematically identify, critically appraise and summarise available evidence on the benefits and harms associated with OIT for the management of people with peanut allergy.

O B J E C T I V E S

To determine the effectiveness and safety of OIT in people with IgE-mediated peanut allergy. In this context, effectiveness means that a patient who is sensitised to peanut and was previously un-able to tolerate ingestion of peanut without developing symptoms within minutes or hours, is, after undergoing peanut OIT, able to ingest peanut and tolerate it without developing any clinical symptoms.

M E T H O D S

Criteria for considering studies for this review

Types of studies

We were primarily interested in randomised controlled trials (RCTs). However, anticipating a limited number of RCTs in this area, we also planned to include studies using quasi-RCT and con-trolled clinical trial (CCT) designs. Our working definition for these designs are:

• RCTs: All participants are allocated at random (e.g. random

number generation, coin flips).

• Quasi-RCTs: The intervention is allocated in a way that is not truly random: for example, allocation by birth, day of the week, month of the year.

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• CCTs: Trials that contains at least two groups, one which receives the treatment and one which acts as a comparison group. The comparison group receives placebo/no treatment other than usual care.

Types of participants

We were interested in studies conducted in children or adults with confirmed peanut allergy. For the purposes of this review, peanut allergy was defined as a history of systemic clinical symp-toms within minutes to hours after the ingestion of peanut in those with objective evidence of sensitisation to peanut protein (Sicherer 2010b). Objective evidence of sensitisation consisted of an elevated serum peanut-specific IgE (ImmunoCAP) level (using cut-points defined by the centre/study) or a positive skin prick test (SPT) response to peanut, where this was defined as a wheal of≥3 mm than that produced by the saline control.

Types of interventions

We were interested in studies investigating peanut OIT compared either with a placebo group, an alternative way of administering desensitisation therapy or treatment with a peanut avoidance con-trol group. We did not include studies which investigated OIT in combination with another treatment if the effect of OIT could not be evaluated independently from the additional treatment.

Types of outcome measures

We consider outcomes measured at any time period during or after treatment. We only included studies which assessed either one or both of our primary outcomes of interest, but we did not restrict studies to those with pre-/post-intervention double-blind, placebo-controlled oral food challenge (OFC) (Plaut 2009).

Primary outcomes

Our primary outcome measures of interest were:

• Increase in the amount of peanut that can be ingested and

tolerated while receiving OIT (i.e. evidence of desensitisation)

• Complete recovery from peanut allergy after completion of OIT whether or not peanut is eaten (i.e. induction of

immunologic tolerance).

Secondary outcomes

Our secondary outcome measures of interest were:

• Changes in generic and disease specific quality of life

• Satisfaction (patients and carers)

• Frequency and severity of further reactions

• Adverse events

• Drop-outs

• Impact on co-morbidities

• Medication use

• Health care utilisation

• Cost-effectiveness

• Immunological changes suggestive of the induction of tolerance (e.g. decreased peanut-specific IgE, increased peanut specific IgG4, and modulation of cytokine production from peanut-stimulated peripheral blood mononuclear cells).

Search methods for identification of studies

We conducted systematic searches for RCTs, quasi-RCTs and CCTs regardless of language, geographical area or publication sta-tus. The date of the last search of all databases was 21 January 2011.

Electronic searches

We searched the following databases: AMED, BIOSIS, CAB, CINAHL, The Cochrane Library, EMBASE, Global Health, Google Scholar, IndMed, ISI Web of Science, LILACS, MED-LINE, PakMediNet, and TRIP. We restricted our searches to the period 1990 to 2012, as peanut OIT was not studied prior to 1990.

MEDLINE search strategies are detailed inAppendix 1and the search strategies used for other databases are found inAppendix 2. We combined subject search strategies with adaptations of the highly sensitive search strategy designed by the Cochrane Col-laboration for identifying randomised controlled trials and con-trolled clinical trials (as described in theCochrane Handbook Ver-sion 5.1.0., Box 6.4.b,Higgins 2011).

Searching other resources

In order to identify unpublished and ongoing work we searched key relevant internet-based databases: Current Controlled Tri-als (http://www.controlled-trials.com); ClinicalTrials.gov (http:// www.clinicaltrials.gov); and Australian New Zealand Clinical Tri-als Registry (http://www.anzctr.org.au). We contacted experts in the field for information on ongoing and unpublished work (Table 1). We also searched the references of all studies identified by the above methods.

Data collection and analysis

Selection of studies

Two reviewers (UN and IV) independently reviewed the titles and abstracts retrieved during the search process and selected all stud-ies that potentially satisfied our inclusion criteria. Both review-ers (UN and IV) then independently assessed the full text copies

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of these potentially eligible studies against the inclusion criteria. Disagreements were resolved through discussion between UN and IV and AS arbitrated in instances where an agreement was not reached. For a PRISMA diagram of study selection, seeAppendix 3.

Data extraction and management

We collected included study details using a form designed for this purpose. Two reviewers (UN and IV) only included data if there was an independently reached consensus. If no agreement was reached, a third reviewer (AS) arbitrated.

The following data were, where available, independently extracted from the included study:

• Trial methods • Country and setting

• Participants (N, mean age, age range)

• Description of intervention

• Outcome measures (primary and secondary) • Study withdrawal

• Adverse events.

Assessment of risk of bias in included studies

Risk of bias was assessed and documented following the domain-based evaluation described in theCochrane Handbook for Systematic Reviews of Interventions5.1.0 (Higgins 2011). We compared the evaluations and discussed and resolved any inconsistencies and disagreements. We assessed the following domains as low, high, or unclear risk of bias:

• Random sequence generation

• Allocation concealment

• Blinding of participants and personnel

• Blinding of outcome assessment

• Incomplete outcome data

• Selective reporting

• Other bias.

Data synthesis

Due to finding only one included study, we were unable to perform meta-analysis in this review. Had sufficient data been available, we planned to use Review Manager for data analysis and quantitative data synthesis. For dichotomous data, we planned to calculate individual and pooled statistics as relative risks (RR) with 95% confidence intervals (CI). For continuous data, we planned to calculate individual and pooled statistics as mean differences (MD) and/or standardised mean differences (SMD) with 95% CI. We planned to conduct meta-analysis using the fixed-effect model. Quantitative analyses of outcomes are, wherever possible, on an intention to treat basis. If we had found sufficient studies, we would have assessed evidence of publication bias graphically using

Funnel plots and statistically using Begg and Egger tests (Begg 1994;Egger 1997).

Subgroup analysis and investigation of heterogeneity We planned to considerthe appropriateness of meta-analysis in the presence of significant clinical or statistical heterogeneity. In future iterations of this review, relevant heterogeneity will be tested for using the I2statistic and significant heterogeneity assumed if I2is greater than 40% (i.e. more than 40% of the variability in outcome between trials could not be explained by sampling variation). In future updates of this review, if data allow, we plan to undertake subgroup analyses in relation to:

• Isolated peanut allergy vs. multiple food allergies • Oral immunotherapy regimen (rush vs. standard)

• Duration of treatment

• Time since completion of treatment.

Sensitivity analysis

We did not find sufficient studies to conduct sensitivity analyses. We planned to undertake sensitivity analyses for the allocation of missing data by best and worst case analysis, and also to undertake a sensitivity analysis on the basis of only including studies judged to be at low risk of bias. We also planned to undertake sensitivity analysis using random effects modelling, comparing the pooled estimates with those derived from undertaking fixed-effect meta-analysis.

Systematic review protocol

The methods used in this review were specified in advance and documented in a protocol which has been published (Nurmatov 2011).

R E S U L T S

Description of studies

See:Characteristics of included studies;Characteristics of excluded studies;Characteristics of ongoing studies.

Results of the search

Our searches identified a total of 746 titles, 16 of which we selected for more detailed interrogation. SeeAppendix 3for a study flow diagram.

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Included studies

We found one small, US-based RCT (Varshney 2011) that en-rolled 28 children aged 1 to 16 years: 19 in the intervention arm and nine in the placebo arm. Subjects were patients with a clini-cal history of peanut allergy and evidence of allergic sensitisation to peanut protein. The active treatment was peanut flour, com-pared with a placebo of oat flour. Patients with a history of severe peanut anaphylaxis, moderate-to-severe persistent asthma, poorly controlled atopic dermatitis, oat allergy (due to use as placebo) or inability to discontinue antihistamines for a short period of time were excluded from the study population. The average length of oral immunotherapy (OIT) was 48 weeks: the initial day es-calation phase lasted two days; the dose eses-calation period (with home dosing and build-up visits) lasted approximately 44 weeks and the maintenance phase lasted approximately four weeks. A double-blind, placebo controlled oral food challenge (OFC) was conducted at week 48. Adverse events were recorded and peanut-specific IgE, IgG and IgG4were measured. Secreted cytokine as-says and T-cell analyses were conducted in subsets of patients. SeeCharacteristics of included studiesfor further details.

Excluded studies

We excluded 15 of the 16 studies we identified from screening, as they did not meet our specified inclusion criteria. Eight stud-ies were either case serstud-ies or open trials without a control group (Anagnostou 2011;Blumchen 2010;Buchanan 2006;Clark 2009;

Jones 2009; Moneret-Vautrin 2010; Nash 2008; Wassermann 2010), two were case reports (Aruanno 2009;Mansfield 2006), two studied forms of immunotherapy other than OIT (Bird 2010;

Kim 2011), and three did not report either of our primary out-comes (Hofmann 2009andWeldon 2011reported only on safety, andThyagarajan 2008reported only immunological outcomes). SeeCharacteristics of excluded studiesfor further information.

Ongoing studies

Searches of clinical trials registries revealed eight studies of peanut OIT for which results had yet to be published. Five of these eight studies were RCTs: NCT00815035 and NCT01324401

compare OIT with placebo and OIT with control, respec-tively; NCT01084174 compares OIT with sublingual im-munotherapy; NCT00932282 compares two lengths of treat-ment with a combination of anti-IgE therapy and OIT; and

ACTRN12608000594325 studies the combination of a probi-otic and OIT, with the intervention group receiving OIT and a probiotic and the control group receiving the same probiotic and placebo OIT. Further details can be found inCharacteristics of ongoing studies.

Risk of bias in included studies

The one included RCT (Varshney 2011) was judged to be at low risk of bias in all domains. Further details of the risk of bias as-sessment can be found in theCharacteristics of included studies

table.

Effects of interventions

Effectiveness of OIT on increasing peanut threshold dose

During the initial day of treatment escalation, 26 out of 28 (93%) individuals reached the maximum cumulative dose of 12mg of peanut protein (equivalent to approximately 1/25t hof a peanut)

or placebo. Two patients in the intervention arm did not reach the 1.5 mg dose and were therefore deemed initial day escalation failures.

Because of adverse events, three patients withdrew from the inter-vention arm (i.e. the two escalation day failures and one additional patient); only 16 participants therefore received the full course of peanut OIT. All nine patients in the placebo arm completed the trial. In those who completed the study, there was a significant increase in the threshold dose of peanut allergen required to trig-ger a reaction in those in the intervention arm compared to those in the placebo arm at the 48 week OFC. All 16 participants who received the full course of active treatment were able to ingest the maximum cumulative dose of 5000 mg (reported by the authors as equivalent to approximately 20 peanuts), compared to a me-dian cumulative dose of 280 mg in the placebo group (range: 0 to 1900; P < 0.001), which equates to approximately one peanut.

Adverse events

Forty-seven per cent (n = 9) of subjects in the intervention arm experienced clinically relevant adverse events during initial day escalation. No placebo subjects had clinically relevant symptoms during initial day escalation. During the build-up phase, peanut OIT subjects had clinically relevant symptoms after 1.2% of 407 build-up doses. One subject treated with peanut OIT experienced mild gastrointestinal symptoms during up-dosing. During home dosing, one placebo group subject experienced adverse events, but no further details about the nature of these symptoms were given. At OFC, one peanut OIT-treated subject experienced mild up-per respiratory symptoms and moderate urticaria. In the placebo treated group, eight subjects experienced clinically relevant symp-toms: one had gastrointestinal symptoms and oral pruritus and a further three subjects had more severe symptoms, but no further details about the nature of these reactions of these were available.

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Medication use

Nine (47%) of the OIT subjects received antihistamine treatment during initial day escalation and two of these subjects required epinephrine. None of the placebo subjects required treatment dur-ing initial day escalation. Durdur-ing build-up dosdur-ing, none of the sub-jects required medication. No detailed information about other medication use during this phase was given. During home dosing, one of the children in the placebo group required treatment with epinephrine. During OFC, one of the peanut OIT treated sub-jects required antihistamines. Three of the placebo group subsub-jects required treatment with epinephrine during OFC. No further de-tails were given about the reason for the use of epinephrine.

Titrated skin prick test (SPT)

In the peanut OIT group, the titrated SPT size decreased from a median of 7 mm (range: 5.5 to 15 mm) at baseline to 1.75 mm (range: 0 to10 mm) by the time of the OFC, which was performed after four weeks of maintenance therapy. In the placebo group, there was a smaller reduction in the titrated SPT size from 7 mm (range; 5.5 to 13 mm) at baseline to 4 mm (range: 0 to 12.5 mm) at OFC.

Changes in peanut-specific IgE

Peanut-specific IgE was measured at the beginning of the study and then at two, six and nine months and at OFC. The median baseline peanut IgE levels in the peanut OIT and placebo groups were 104 kU/L (range; 31 to 685 kU/L) and 57 kU/L (range; 20 to 188 kU/L), respectively (P = 0.02). After two months, the median peanut-specific IgE of peanut OIT subjects increased to 308 kU/L (P < 0.01). At OFC, median peanut-specific IgE was not significantly different from baseline. Placebo subjects showed no changes.

Changes in peanut-specific IgG4

Peanut-specific IgG4significantly increased from baseline at all time-points in peanut OIT treated subjects, but did not change in placebo subjects (P < 0.001).

Other immunological changes

Peanut OIT treated subjects had an initial increase in specific-IgE (P < 0.01), but did not show any significant changes from baseline by the time of the OFC.

Cytokines and T-cell parameters were measured at baseline, nine months, and at the time of OFC in eight peanut subjects and nine placebo subjects who had cultured peripheral blood mononuclear cells (PBMCs) at these time points. At nine months and OFC, IL-5 and IL-13 were significantly decreased from baseline in peanut OIT subjects (P < 0.03). There was a transient increase in

TGF-βlevels in peanut OIT subjects at 9 months (P = 0.03), but levels returned to baseline by the time of the OFC. In placebo arm subjects, there was no change in IL-5, IL-13 or TGF-β. There was no significant change found in IL-10 or IFN-γ in either peanut OIT or placebo subjects.

Drop-outs

Two subjects in the peanut OIT treated arm did not reach the 1.5 mg dose and therefore did not continue the study. During the build-up phase, one additional peanut OIT subject withdrew from the study after the first dose escalation because of mild gas-trointestinal symptoms precluding further up-dosing.

Other outcomes

No other outcomes specified in the protocol were reported in the included study.

D I S C U S S I O N

Summary of main results

This review identified one small RCT at low risk of bias. This RCT demonstrated that it is possible to induce desensitisation in children treated with allergen-specific peanut OIT, enabling a sub-stantial increase in the amount of peanut to be safely consumed whilst receiving OIT. There was a significant increase in threshold dose of peanut allergen tolerated by children after peanut OIT; in the intervention group, the children ingested the maximum cumu-lative dose of 5000 mg (equivalent to approximately 20 peanuts), whereas in the placebo group the mean amount of peanut allergen ingested was 280 mg (range, 0 to 1900 mg, P < 0.001). Treat-ment was associated with relevant immune-modulatory changes suggesting that OIT may have longer-term benefits, but data were not available on induction of tolerance. However, adverse events associated with treatment were common and in some cases these reactions were severe, raising important concerns about the safety of the OIT regimen employed in this trial. There is no evidence on the cost-effectiveness of this treatment approach. Concerns around safety and cost-effectiveness mean that although OIT for peanut allergy should at present be regarded as a promising line of enquiry, it is not as yet appropriate for incorporating into clinical care.

Overall completeness and applicability of evidence

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Although the evidence identified in this review is consistent with that reported in our earlier systematic review of peanut OIT case series (Sheikh 2012), the only rigorous evidence on this subject comes from one small eligible RCT in children (Varshney 2011). There is therefore at present only limited evidence to inform care provision and, given the concerns about safety, the applicability of this evidence is limited. We found no evidence in relation to the management of adults.

Quality of the evidence

The one included trial was well-conducted, but it was small and involved children from only two centres (Varshney 2011), limiting its external validity.

Potential biases in the review process

We have undertaken comprehensive searches of a range of data sources. That said, there remains the possibility that we may have failed to uncover some potentially eligible studies. We are not aware of any other sources of bias in the review process.

Agreements and disagreements with other studies or reviews

The findings from our systematic review are broadly consistent with other reviews on this subject (Fisher 2011; Sheikh 2012), which suggest that whilst desensitisation can be achieved through peanut OIT there is at present no evidence in relation to the induction of tolerance. In a Phase I trial from the USA (Weldon 2011), 24 subjects aged 5 to 45 years old received 3777 doses of OIT. Twenty-one out of 24 patients reported reactions; 85 per cent of those were mild and resolved with antihistamines (abdominal pain 28%, oropharyngeal pruritus 27% and lip pruritis 11%) and three reactions were severe and resolved with epinephrine.

A U T H O R S ’ C O N C L U S I O N S Implications for practice

Peanut OIT represents a promising, potentially disease-modifying therapeutic approach for the management of IgE-mediated peanut allergy. However, currently there is insufficient evidence in terms of long-term effectiveness, safety and cost-effectiveness of peanut OIT to recommend its routine use in clinical practice.

Implications for research

Further research is needed to better establish the effectiveness, sa-fety, and cost-effectiveness of allergen-specific peanut OIT. In particular, future trials need to establish whether clinical and im-munologic tolerance can successfully be achieved after OIT is dis-continued, and to understand the impact of treatment on the qual-ity of life of patients and relevant family members. There is also a need to ensure that the full age spectrum of patients affected by peanut allergy is reflected in future trials. The results of on-going trials will, in the future, shed light on long-term oral immune tol-erance issues in subjects with IgE-mediated peanut allergy.

A C K N O W L E D G E M E N T S

We wish to thank to the Chief Scientist Office of the Scottish Gov-ernment for their funding our previous grant “Establishing the ef-fectiveness, cost-effectiveness and safety of oral desensitisation for food allergy: a systematic review and meta-analysis of intervention studies” (CZG/2/493).

We also thank Managing Editors from the Cochrane Tobacco Addiction Group, Dr. Monaz Mehta, Lindsay Stead and Jamie Hartmann-Boyce for their assistance during the review process.

R E F E R E N C E S

References to studies included in this review

Varshney 2011 {published data only}

Varshney P, Jones S, Scurlock AM, Perry TT, Kemper A, Steele P, et al.A randomized controlled study of peanut oral immunotherapy: clinical desensitization and modulation of the allergic response. Journal of Allergy and Clinical Immunology2011;127:654–60.

References to studies excluded from this review

Anagnostou 2011 {published data only}

Anagnostou K, Clark A, King Y, Islam S, Deighton J, Ewan P. Efficacy and safety of high-dose peanut oral immunotherapy with factors predicting outcome. Clinical & Experimental Allergy2011;41(9):1273–81.

Aruanno 2009{published data only}

Aruanno A, Nucera E, et al.Oral specific desensitisation in food allergy and loss of tolerance after interruption of the maintenance phase: five case reports. Allergy2009;64 (Suppl.90):167.

Bird 2010 {published data only}

Bird JA, Pons L, Kulis M, Kemper AR, Laubach S, Kim

9 Allergen-specific oral immunotherapy for peanut allergy (Review)

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E, et al.Double-blinded placebo controlled sublingual immunotherapy (SLIT) trial for peanut allergy.Journal of Allergy and Clinical Immunology2010;125(2):AB20–78.

Blumchen 2010 {published data only}

Blumchen K, Ulbricht H, Staden U, Dobberstein K, Beschomer J, Lopes de Oliveira LC, et al.Oral peanut immunotherapy in children with peanut anaphylaxis. Journal of Allergy and Clinical Immunology2010;126:83–91.

Buchanan 2006 {published data only}

Buchanan A, Scurlock AM, Jones SM, Christie L, Althage KM, Pons L, et al.Oral desensitization and induction of tolerance in peanut-allergic children.Journal of Allergy and Clinical Immunology2006;117:S327.

Clark 2009 {published data only}

Clark AT, Islam S, King Y, Deighton J, Anagnostou K, Ewan PW. Successful oral tolerance induction in severe peanut allergy.Allergy2009;64(8):1218–20.

Hofmann 2009 {published data only}

Hofmann AM, Scurlock AM, Jones SM, Palmer KP, Lokhnygina Y, Steele PH, et al.Safety of a peanut oral immunotherapy protocol in children with peanut allergy. Journal of Allergy and Clinical Immunology2009;124(2): 286–91.

Jones 2009 {published data only}

Jones SM, Pons L, Roberts JL, Scurlock AM, Perry TT, Kulis M, et al.Clinical efficacy and immune regulation with peanut oral immunotherapy.Journal of Allergy and Clinical Imunology2009;124(2):292–300.

Kim 2011 {published data only}

Kim EH, Bird JA, Kulis M, Laubach S, Pons L, Shreffler W, et al.Sublingual immunotherapy for peanut allergy: clinical and immunological evidence of desensitization.Journal of Allergy and Clinical Immunology2011;127(3):640–6.

Mansfield 2006 {published data only}

Mansfield L. Sussessful oral desensitisation for systemic peanut allergy. Annals of Allergy, Asthma and Immunology 2006;97(2):266–7.

Moneret-Vautrin 2010 {published data only}

Moneret-Vautrin DA, Petit N, Parisot L, Dumont P, Morisset M, Beadouin E, et al.Efficiency and safety of oral immunotherapy protocols in peanut allergy: Pilot study on 51 patients.Revue Française d’Allergologie et d’Immunologie Clinique2010;50(5):434–42.

Nash 2008 {published data only}

Nash SD, Steele PH, Kamilaris JS, Pons L, Kulis MD, Lee LA, et al.Oral immunotherapy for children with peanut allergy. Journal of Allergy and Clinical immunology2008;

121:S136.

Thyagarajan 2008 {published data only}

Thyagarajan A, Jones SM, Pons L, Kulis M, Smith PB, Steele PH, et al.Immunoglobulin changes using different dosing regimens of peanut oral immunotherapy (OIT) in peanut allergic patients.Journal of Allergy and Clinical Immunology2008;125(2):AB21.

Wassermann 2010 {published data only}

Wassermann RL, Mansfield LE, Gallucci AR, Hutteman HR, Ruvalcaba AM, Long NA, et al.Office based oral desensitization of patients with anaphylactic sensitivity to foods is safe and effective. Journal of Allergy and Clinical Immunology2010;125:AB59(233).

Weldon 2011 {published data only}

Weldon B, Yu G, Neale-May S, Hunter TT, Nadeau K. THe safety of peanut oral immunotherapy in peanut allergic subjects in a single center trial. Journal of Allergy and Clinical Immunology2011;127(2):AB25.

References to ongoing studies

ACTRN12608000594325 {unpublished data only} Study of the effectiveness of Probiotics and Peanut Oral Immunotherapy (P-POIT) in inducing desensitisation or tolerance in children with peanut allergy. Ongoing study December 2008.

NCT00598039 {unpublished data only}

Oral Peanut Immunotherapy for Peanut Allergic Patients. Ongoing study March 2003.

NCT00815035 {unpublished data only}

Oral Immunotherapy for Peanut Allergy. Ongoing study June 2009.

NCT00932282 {unpublished data only}

Peanut Oral Immunotherapy and Anti-IgE for Peanut Allergy. Ongoing study July 2009.

NCT01084174 {unpublished data only}

A Randomized, Double-Blind, Placebo-Controlled Pilot Study of Sublingual/Oral Immunotherapy for the Treatment of Peanut Allergy. Ongoing study March 2010.

NCT01259804 {unpublished data only} Efficacy and Safety of High-dose Peanut Oral Immunotherapy With Factors Predicting Outcome. Ongoing study Jan 2008.

NCT01274429 {unpublished data only}

Peanut Oral Immunotherapy (OIT) - Initial Pilot Study in Adults. Ongoing study Dec 2010.

NCT01324401 {unpublished data only}

Oral Peanut Immunotherapy. Ongoing study March 2011.

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Burks AW. Peanut allergy.Lancet2008;371:1538–46.

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Calderon MA, Penagos M, Sheikh A, Canonica GW, Durham SR. Sublingual immunotherapy for allergic conjunctivitis: Cochrane systematic review and meta-analysis. Clinical and Experimental Allergy2011;41(9): 1263–72.

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Calderon MA, Boyle RJ, Penagos M, Sheikh A. Immunotherapy: The meta-analysis. What have we learned?.Immunology and Allergy Clinics of North America 2011;31(2):159–73.

Clark 2008

Clark AT, Ewan PW. Good prognosis, clinical features, and circumstances of peanut and tree nut reactions in children treated by a specialist allergy center. Journal of Allergy and Clinical Immunology2008;122(2):286–9.

Cummings 2010

Cummings AJ, Knibb RC, Erlewyn-Lajenesse M, King RM, Roberts G, Lucas JSA. Management of nut allergy influences quality of life and anxiety in children and their mothers. Pediatric Allergy and Immunology2010;21:586–94.

de Leon 2007

de Leon MP, Rolland JM, O’Hehir RE. The peanut allergy epidemic: Allergen molecular characterisation and prospects for specific therapy.Expert Reviews in Molecular Medicine 2007;9(1):1–18.

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Fisher 2011

Fisher HR, du Toit G, Lack G. Specific oral tolerance induction in food allergic children: is oral desensitisation more effective than allergen avoidance.Archives of Disease in Childhood2011;96:259–64.

Gallagher 2011

Gallagher M, Worth A, Cunningham-Burley S, Sheikh A. Epinephrine auto-injector use in adolescents at risk of anaphylaxis: a qualitative study in Scotland, UK.Clinical and Experimental Allergy2011;41(6):869–77.

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Hourihane JO, Aiken R, Briggs R, Gudgeon LA, Grimshaw KE, DunnGalvin A, et al.The impact of government advice to pregnant mothers regarding peanut avoidance on the prevalence of peanut allergy in United Kingdom children at school entry.The Journal of Allergy and Clinical Immunology 2007;119:1197–202.

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Moneret-Vautrin DA. Sublingual and oral immunotherapy for food allergy: outcome and immunological modifications. Review Francaise D’Allergologie2011;51:286–294.

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Mullins RJ, Dear KBG, Tang MLK. Characteristics of childhood peanut allergy in the Australian Capital Territory, 1995 to 2007.Journal of Allergy and Clinical Immunology 2009;123(3):689–93.

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Sicherer SH, Munoz-Furlong A, Godbold JH, Sampson HA. US prevalence of self-reported peanut, tree nut, and sesame allergy: 11-year follow-up.Journal of Allergy and Clinical Immunology2010;125(6):1322–6.

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C H A R A C T E R I S T I C S O F S T U D I E S

Characteristics of included studies [ordered by study ID]

Varshney 2011

Methods Randomised double-blind, placebo-controlled trial

Setting: University health centres, USA

Participants 28 children aged 1 to 16 years from local allergy and immunology clinics or surrounding community physician offices (19 intervention, 9 control). Av. age 7 years

Inclusion criteria: clinical history of reaction to peanut within 60min of ingestion; peanut CAP-FEIA >15 kU/L or >7 kU/L if a significant reaction occurred within 6m of enrol-ment; positive skin prick test

Excluded if: history of severe peanut anaphylaxis; moderate to severe persistent asthma; poorly controlled atopic dermatitis; oat allergy; or inability to discontinue antihistamines during OFC or skin testing

Interventions Oral immunotherapy for approx. 48wks (home dosing/build-up visits approx. 44wks; maintenance phase approx. 4wks; OFC at wk 48)

Active = peanut flour; placebo = oat flour

Initial day escalation phase:Day 1: dosing started at 0.1 mg peanut protein or placebo, approx. doubled every 30min until 6 mg reached/subject had symptoms. Day 2: Dosing began at highest tolerated dose during day 1

Home dosing:Children instructed to ingest each dose mixed in a food vehicle daily Dose escalations:Every 2 wks, doses increased 50 - 100% until 75 mg dose, 25-33% until 400 mg maintenance dose reached

Maintenance phase:Ingest 400 mg dose daily for 1m

Outcomes Double-blind, placebo controlled OFC (increasing doses of peanut or oat flour every 10 to 20mins up to cumulative dose of 5000 mg); adverse events; peanut-specific IgE, IgG, and IgG4; secreted cytokine assays and T-cell analyses in subset of participants

Notes Small sample size

Participants followed up after wk 48, investigating long-term immune tolerance (data not yet available)

Risk of bias

Bias Authors’ judgement Support for judgement

Random sequence generation (selection bias)

Low risk “A randomization table was generated to

assign subjects in a 2:1 ratio to receive peanut flour or placebo”

Allocation concealment (selection bias) Low risk “Allocation was performed before

enrol-ment and saved in a locked database acces-sible only by laboratory personnel to keep clinical staff and subjects unaware of

up-13 Allergen-specific oral immunotherapy for peanut allergy (Review)

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Varshney 2011 (Continued)

coming assignments” Blinding of participants and personnel

(performance bias) All outcomes

Low risk “Investigators, subjects, and families

re-mained blind to the assigned intervention as well laboratory studies until completion of the food challenge”

Blinding of outcome assessment (detection bias)

All outcomes

Low risk “Challenges were administered by a nurse

or physician who was also blind to testing materials”

Incomplete outcome data (attrition bias) All outcomes

Low risk Final data excludes 3 participants from

treatment group who were removed from the study before completion due to adverse events

Selective reporting (reporting bias) Low risk All prespecified outcomes reported

m: month; min: minute; OFC: oral food challenge; OIT: oral immunotherapy; wk(s): week(s)

Characteristics of excluded studies [ordered by study ID]

Study Reason for exclusion

Anagnostou 2011 Open trial without a control group

Aruanno 2009 Case reports

Bird 2010 Sublingual immunotherapy (not a study of OIT) Blumchen 2010 Case series

Buchanan 2006 Case series

Clark 2009 Open trial without a control group

Hofmann 2009 Immunological outcomes only (tolerance and desensitisation not measured)

Jones 2009 Case series

Kim 2011 Sublingual immunothertapy (not a study of OIT) Mansfield 2006 Case report

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(Continued)

Moneret-Vautrin 2010 Open trial without a control group

Nash 2008 Case series

Thyagarajan 2008 Immunological outcomes only (tolerance and desensitisation not measured) Wassermann 2010 Case series

Weldon 2011 Safety analysis only (tolerance and desensitisation not measured)

Characteristics of ongoing studies [ordered by study ID]

ACTRN12608000594325

Trial name or title Study of the effectiveness of Probiotics and Peanut Oral Immunotherapy (P-POIT) in inducing desensitisation or tolerance in children with peanut allergy

Methods Randomized controlled trial

Participants Approx. 90 children aged 1 to 10 with confirmed diagnosis of peanut allergy and no history of severe anaphylaxis to peanut

Interventions Intervention: Lactobacillus rhamnosus GG (LGG) + peanut OIT Control: LGG + placebo OIT

LGG: 2x10E10 daily for 18m

OIT: 18m. Modified rush phase: increasing doses, starting at 0.1 mg peanut protein, doubling every 30min to reach dose of 12 mg of peanut protein. Build-up phase: daily dose starting at 24 mg, increased every 2wks until dose of 2 g is reached (expected to take 8m). Dose then maintained at 2 g for approx 10m. Same for placebo OIT

Outcomes Primary: increase in tolerance by combining peanut OIT with probiotics Secondary: Desensitisation, immunologic changes

Starting date December 2008

Contact information A/Prof Mimi Tang: mimi.tang@rch.org.au Notes Expected completion date not specified

15 Allergen-specific oral immunotherapy for peanut allergy (Review)

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NCT00598039

Trial name or title Oral Peanut Immunotherapy for Peanut Allergic Patients Methods Safety/efficacy study, open label, no control group

Participants Approx. 40 subjects 1 to 16 years old with diagnosed peanut allergy. Subjects with history of severe anaphylaxis to peanut excluded

Interventions Peanut OIT (open intervention), no further details provided

Outcomes Primary: Double-blind, placebo controlled OFC and second food challenge 1m after being off of peanut Secondary: IgE to peanut decrease below a level of 2

Starting date March 2003

Contact information Contact information not provided. PI: Wesley Burks, MD, Duke University Notes Est. study completion date July 2012

NCT00815035

Trial name or title Oral Immunotherapy for Peanut Allergy

Methods Randomized, double-blind, crossover safety/efficacy study

Participants Approx. 60 participants aged 1 to 6 years with presence of peanut-specific IgE and history of significant clinical symptoms occurring within 60mins of ingesting peanuts. Participants excluded if they have history of severe anaphylaxis to peanut

Interventions Intervention: Peanut OIT Control 1: Placebo OIT Control 2: No treatment

Peanut OIT and placebo: modified rush immunotherapy on day 1 followed by daily dose with increase in dose at least every 2 wks up to maintenance dose of 4 g

Outcomes Primary: lower risk of anaphylactic reactions, long-term tolerance Secondary: molecular level effect on humoral activity/response Starting date June 2009

Contact information Contact information not provided. PI: Wesley Burks, MD, Duke University

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NCT00932282

Trial name or title Peanut Oral Immunotherapy and Anti-IgE for Peanut Allergy Methods Randomized, open label safety/efficacy study

Participants Approx. 10 subjects aged 12 or older with peanut-specific IgE and history of clinical symptoms occurring within 60mins of peanut ingestion. Participants with history of severe anaphylaxis to peanut not included Interventions Peanut OIT + omalizumab (anti-IgE): 12m vs 24m maintenance therapy

4m omalizumab treatment before peanut OIT, omalizumab continued until 1m post maintenance therapy. Initial desensitization phase over 2d to goal of 950 mg peanut powder followed by build up phase over 4m to goal maintenance dose of 8000 mg peanut powder

Outcomes Primary: Tolerate a dose of 20gm peanut flour during OFC

Secondary: Incidence of adverse events during initial escalation and build up phase Starting date July 2009

Contact information jane.hainline@duke.edu; alison.edie@duke.edu

Notes Est. completion date July 2014

NCT01084174

Trial name or title A Randomized, Double-Blind, Placebo-Controlled Pilot Study of Sublingual/Oral Immunotherapy for the Treatment of Peanut Allergy

Methods Randomized, double-blind, parallel assignment safety/efficacy study

Participants 30 subjects aged 6 to 21 with clinical history of peanut allergy, confirmed by peanut specific IgE and skin prick test

Interventions Active sublingual immunotherapy (SLIT) for peanut allergy + placebo peanut OIT vs active peanut OIT + placebo SLIT

SLIT and OIT dose increases for 16wks, then daily maintenance dose for 12m Outcomes Primary: 10 fold increase in tolerance

Secondary: Adverse events, changes in clinical and mechanistic endpoints, peanut tolerance

Starting date March 2010

Contact information Contact information not provided, PI: Robert Wood, MD, Johns Hopkins University

Notes Est. completion date Jan 2012

17 Allergen-specific oral immunotherapy for peanut allergy (Review)

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NCT01259804

Trial name or title Efficacy and Safety of High-dose Peanut Oral Immunotherapy With Factors Predicting Outcome Methods Open pilot study, no control group

Participants 22 children with peanut allergy aged 7-17

Interventions Peanut OIT: gradual updosing with every 2 wks (8-38wks) to 800 mg protein (5 peanuts/day); then 30wks maintenance

Outcomes Primary: Pass/fail peanut challenge No secondary outcomes listed

Starting date Jan 2008

Contact information Contact information not provided. PI: Andrew T. Clark, Cambridge Biomedical Campus, University of Cambridge

Notes Est. completion date Jan 2012

NCT01274429

Trial name or title Peanut Oral Immunotherapy (OIT) - Initial Pilot Study in Adults Methods Open label, no control group

Participants Approx. 20 adults aged 18 to 50 with diagnosis of peanut allergy or clinical history of peanut allergy, positive SPT, and peanut-specific IgE. Subjects with severe anaphylaxis to peanut excluded

Interventions Peanut OIT (no control).

Begins with modified rush (0.1 mg of peanut protein, dose doubled every 30min up to 6 mg peanut protein) . Dose given daily, escalation visits every 2wks. Maintenance phase starts at 2300 mg, taken daily

Outcomes Primary: lower risk of anaphylactic reactions in adults, long-term tolerance Secondary: molecular level effect on humoral activity/response in adults

Starting date Dec 2010

Contact information jane.hainline@duke.edu; alison.edie@duke.edu

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NCT01324401

Trial name or title Oral Peanut Immunotherapy

Methods Randomized, open-label, parallel-assignment safety/efficacy study of clinical symptoms after ingestion of peanuts

Participants 32 subjects 7 to 12 years old with diagnosis of peanut allergy via skin prick test and history. Excludes participants with history of severe anaphylactic reaction to peanut requiring treatment with 2+ administrations of epinephrine or hospitalisation

Interventions Intervention: Peanut OIT, daily escalating dosages as determined in modified rush phase, escalated until daily dose of 4000 mg is reached

Control: No treatment

Outcomes Primary: tolerance

Secondary: desensitisation; adverse events

Starting date March 2011

Contact information abrennan3@partners.org; skubala@partners.org

Notes Est. completion date August 2012

OIT: oral immunotherapy; m: month; min: minutes; wk(s): week(s)

19 Allergen-specific oral immunotherapy for peanut allergy (Review)

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D A T A A N D A N A L Y S E S

This review has no analyses.

A D D I T I O N A L T A B L E S Table 1. List of experts contacted

Name of author Country

Dr. Egidio Barbi Italy

Dr. Kirsten Beyer Germany

Prof. Wesley Burks USA

Dr. Andrew T Clark UK

Dr. Ernesto Enrique Spain

Dr. Mansouri Iran

Dr. Paolo Meglio Italy

Professor Moneret-Vautrin DA France

Dr. Martine Morisset France

Prof. Bodo Niggemann Germany

Prof. Giovanni Pajno Italy

Prof. G Patriarca Italy

Dr. Lydia Zapatero Remon Spain

Dr. Fernandez-Rivas Spain

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A P P E N D I C E S

Appendix 1. Medline search strategy

Nr. Search term

1 Peanut Hypersensitivity (MESH) 2 Peanut allerg*

3 Peanut-allergic

4 Arachis hypogaea allergy 5 Food allergy

6 Food hypersen*

7 1 OR 2 OR 3 OR 4 OR 5 OR 6 8 Desensitization, immunologic (MESH) 9 Desensiti* 10 Immunotherapy (MESH) 11 Immunotherapy 12 Oral immunotherapy 13 Oral desensiti* 14 Rush immunotherapy

15 Specific oral tolerance induction

16 8 OR 9 OR 10 OR 11 OR 12 OR 13 OR 14 OR 15 17 Analytical stud*

18 Intervention studies (MESH) 19 Experimental stud*

20 Etiology 21 Trial

22 Clinical trial (MESH)

21 Allergen-specific oral immunotherapy for peanut allergy (Review)

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(Continued)

23 Clinical trial

24 Controlled clinical trial 25 Uncontrolled trial

26 Randomized controlled trial (MESH) 27 Randomi* controlled trial

28 Quasi-randomi* controlled trial 29 Non-randomi* trial

30 Placebos (MESH)

31 Random allocation (MESH) 32 Double-blind method (MESH) 33 Double-blind design

34 Single-blind method

35 Random*

36 Controlled before after design 37 Interrupted time series 38 Case series

39 17 OR 18 OR 19 OR 20 OR 21 OR 22 OR 23 OR 24 OR 25 OR 26 OR 27 OR 28 OR 29 OR 30 OR 31 OR 32 OR 33 OR 34 OR 35 OR 36 OR 37 OR 38

40 7 AND 16 AND 39

Appendix 2. Other databases search strategy

Search terms for (The Cochrane Library, LILACS, TRIP, CINAHL, ISI Web of Science, BIOSIS, PakMediNet, IndMed, Google Scholar) 1990-2012

(peanut allergy or arachis hypogaea or legume* or nut allergy or food hypersensitivity or food allergy)

AND

(immunologic, desensiti* or immunotherapy or oral immunotherapy or oral desensiti* or specific oral tolerance induction or oral tolerance induction)

AND

(intervention stud* or experimental stud* or trial or clinical trial* or controlled clinical trial or random* or randomi* controlled trial or quasi randomi* or non randomi* or random allocation or single blind method or double blind method or triple blind method)

(25)

Appendix 3. PRISMA flow diagram of study selection Figure 1

Figure 1. PRISMA search flow diagram. Top level does not include searches that returned no results (AMED, PakMediNet, IndMed, LILACS).

H I S T O R Y

Protocol first published: Issue 2, 2011 Review first published: Issue 9, 2012

C O N T R I B U T I O N S O F A U T H O R S

UN developed the protocol, undertook searches, study selection, critical appraisal and drafting the review. IV developed the protocol, undertook searches, study selection, critical appraisal and commented on drafts of the review. GD helped with the design of the review protocol and commented on drafts of the final review. FER helped with the drafting the review protocol and commented on drafts of the review manuscript. AS conceived this review, oversaw all aspects of the development of the protocol and the conducting of the review and commented on drafts of this review.

23 Allergen-specific oral immunotherapy for peanut allergy (Review)

(26)

D E C L A R A T I O N S O F I N T E R E S T

None known.

S O U R C E S O F S U P P O R T

Internal sources

• No sources of support supplied

External sources

• Chief Scientist’s Office of the Scottish Government, UK.

D I F F E R E N C E S B E T W E E N P R O T O C O L A N D R E V I E W

In the protocol, we implied but did not clearly specify that this review was focused on studying allergen-specific OIT; the title and background have now been revised to better reflect the focus of this work. We have removed a reference from the protocol (Li 2001).

I N D E X T E R M S

Medical Subject Headings (MeSH)

Arachis hypogaea [immunology]; Administration, Oral; Allergens [administration & dosage; immunology]; Desensitization, Im-munologic [adverse effects;∗methods]; Epinephrine [therapeutic use]; Flour; Histamine H1 Antagonists [therapeutic use]; Peanut Hypersensitivity [immunology;∗therapy]; Randomized Controlled Trials as Topic

MeSH check words

Figure

Figure 1. PRISMA search flow diagram. Top level does not include searches that returned no results (AMED, PakMediNet, IndMed, LILACS).

Figure 1.

PRISMA search flow diagram. Top level does not include searches that returned no results (AMED, PakMediNet, IndMed, LILACS). p.25

References