Systematic review and meta-analyses on the accuracy of diagnostic tests for IgE-mediated food allergy

The European Academy of Allergy and Clinical Immunology (EAACI) is updating the Guidelines on Food Allergy Diagnosis. We aimed to undertake a systematic review of the literature with meta-analyses to assess the accuracy of diagnostic tests for IgE-mediated food allergy. We searched three databases (Cochrane CENTRAL (Trials), MEDLINE (OVID) and Embase (OVID)) for diagnostic test accuracy studies published between 1 October 2012 and 30 June 2021 according to a previously published protocol (CRD42021259186). We independently screened abstracts, extracted data from full texts and assessed risk of bias with QUADRAS 2 tool in duplicate. Meta-analyses were undertaken for food-test combinations for which three or more studies were available. A total of 149 studies comprising 24,489 patients met the inclusion criteria and they were generally heterogeneous. 60.4% of studies were in children ≤12 years of age, 54.3% were undertaken in Europe, ≥95% were conducted in a specialized paediatric or allergy clinical setting and all included oral food challenge in at least a percentage of enrolled patients, in 21.5% double-blind placebo-controlled food challenges. Skin prick test (SPT) with fresh cow's milk and raw egg had high sensitivity (90% and 94%) for milk and cooked egg allergies. Specific IgE (sIgE) to individual components had high specificity: Ara h 2-sIgE had 92%, Cor a 14-sIgE 95%, Ana o 3-sIgE 94%, casein-sIgE 93%, ovomucoid-sIgE 92/91% for the diagnosis of peanut, hazelnut, cashew, cow's milk and raw/cooked egg allergies, respectively. The basophil activation test (BAT) was highly specific for the diagnosis of peanut (90%) and sesame (93%) allergies. In conclusion, SPT and specific IgE to extracts had high sensitivity whereas specific IgE to components and BAT had high specificity to support the diagnosis of individual food allergies.

EAACI guidelines on the diagnosis of IgE-mediated food allergy

This European Academy of Allergy and Clinical Immunology guideline provides recommendations for diagnosing IgE-mediated food allergy and was developed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. Food allergy diagnosis starts with an allergy-focused clinical history followed by tests to determine IgE sensitization, such as serum allergen-specific IgE (sIgE) and skin prick test (SPT), and the basophil activation test (BAT), if available. Evidence for IgE sensitization should be sought for any suspected foods. The diagnosis of allergy to some foods, such as peanut and cashew nut, is well supported by SPT and serum sIgE, whereas there are less data and the performance of these tests is poorer for other foods, such as wheat and soya. The measurement of sIgE to allergen components such as Ara h 2 from peanut, Cor a 14 from hazelnut and Ana o 3 from cashew can be useful to further support the diagnosis, especially in pollen-sensitized individuals. BAT to peanut and sesame can be used additionally. The reference standard for food allergy diagnosis is the oral food challenge (OFC). OFC should be performed in equivocal cases. For practical reasons, open challenges are suitable in most cases. Reassessment of food allergic children with allergy tests and/or OFCs periodically over time will enable reintroduction of food into the diet in the case of spontaneous acquisition of oral tolerance.

Impact of Allocation Concealment and Blinding in Trials Addressing Treatments for COVID-19: A Methods Study

We aimed to assess the impact of allocation concealment and blinding on the results of coronavirus disease 2019 (COVID-19) trials, using the World Health Organization COVID-19 database (to February 2022). We identified 488 randomized trials comparing drug therapeutics with placebo or standard care in patients with COVID-19. We performed random-effects meta-regressions comparing the results of trials with and without allocation concealment and blinding of health-care providers and patients. We found that, compared with trials with allocation concealment, trials without allocation concealment may estimate treatments to be more beneficial for mortality, mechanical ventilation, hospital admission, duration of hospitalization, and duration of mechanical ventilation, but results were imprecise. We did not find compelling evidence that, compared with trials with blinding, trials without blinding produce consistently different results for mortality, mechanical ventilation, and duration of hospitalization. We found that trials without blinding may estimate treatments to be more beneficial for hospitalizations and duration of mechanical ventilation. We did not find compelling evidence that COVID-19 trials in which health-care providers and patients are blinded produce different results from trials without blinding, but trials without allocation concealment estimate treatments to be more beneficial compared with trials with allocation concealment. Our study suggests that lack of blinding may not always bias results but that evidence users should remain skeptical of trials without allocation concealment.

Effectiveness of face masks for reducing transmission of SARS-CoV-2: a rapid systematic review

This rapid systematic review of evidence asks whether (i) wearing a face mask, (ii) one type of mask over another and (iii) mandatory mask policies can reduce the transmission of SARS-CoV-2 infection, either in community-based or healthcare settings. A search of studies published 1 January 2020-27 January 2023 yielded 5185 unique records. Due to a paucity of randomized controlled trials (RCTs), observational studies were included in the analysis. We analysed 35 studies in community settings (three RCTs and 32 observational) and 40 in healthcare settings (one RCT and 39 observational). Ninety-five per cent of studies included were conducted before highly transmissible Omicron variants emerged. Ninety-one per cent of observational studies were at 'critical' risk of bias (ROB) in at least one domain, often failing to separate the effects of masks from concurrent interventions. More studies found that masks (n = 39/47; 83%) and mask mandates (n = 16/18; 89%) reduced infection than found no effect (n = 8/65; 12%) or favoured controls (n = 1/65; 2%). Seven observational studies found that respirators were more protective than surgical masks, while five found no statistically significant difference between the two mask types. Despite the ROB, and allowing for uncertain and variable efficacy, we conclude that wearing masks, wearing higher quality masks (respirators), and mask mandates generally reduced SARS-CoV-2 transmission in these study populations. This article is part of the theme issue 'The effectiveness of non-pharmaceutical interventions on the COVID-19 pandemic: the evidence'.

Grading of recommendations assessment, development, and evaluation concept article 5: addressing intransitivity in a network meta-analysis

OBJECTIVES

This article describes considerations for addressing intransitivity when assessing the certainty of the evidence from network meta-analysis (NMA) using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Intransitivity is induced by effect modification, that is, when the magnitude of the effect between an intervention and outcome differs depending on the level of another factor.

STUDY DESIGN AND SETTING

To develop this GRADE concept paper, the lead authors conducted iterative discussions, computer simulations, and presentations to the GRADE project group and at GRADE working group meetings. The GRADE Working Group formally approved the article in July 2022.

RESULTS

NMA authors can have a higher or a lower threshold to rate down the certainty of the evidence due to intransitivity, which depends on the extent of their concerns regarding the trustworthiness of indirect comparisons, and their view of the relative problems with rating down excessively or insufficiently. NMA authors should consider three main factors when addressing intransitivity: the credibility of effect modification, the strength of the effect modification, and the distribution of effect modifiers across the direct comparisons. To avoid double counting limitations of the evidence, authors should consider the relationship between intransitivity and other GRADE domains.

CONCLUSION

NMA authors face theoretic and pragmatic challenges and in most situations need to assess intransitivity without the availability of empirical data. Thus, explicitness regarding perspective is crucial.

Outcomes reported in randomized controlled trials for mixed and non-IgE-mediated food allergy: Systematic review

BACKGROUND

Mixed and non-IgE-mediated food allergy is a subset of immune-mediated adverse food reactions that can impose a major burden on the quality of life of affected patients and their families. Clinical trials to study these diseases are reliant upon consistent and valid outcome measures that are relevant to both patients and clinicians, but the degree to which such stringent outcome reporting takes place is poorly studied.

OBJECTIVE

As part of the Core Outcome Measures for Food Allergy (COMFA) project, we identified outcomes reported in randomized clinical trials (RCT) of treatments for mixed or non-IgE-mediated food allergy.

DESIGN

In this systematic review, we searched the Ovid, MEDLINE and Embase databases for RCTs in children or adults investigating treatments for food protein-induced enterocolitis syndrome, food protein-induced allergic proctocolitis, food protein-induced enteropathy and eosinophilic gastrointestinal disorders including eosinophilic esophagitis [EoE], eosinophilic gastritis and eosinophilic colitis published until 14 October 2022.

RESULTS

Twenty-six eligible studies were identified, with 23 focused on EoE (88%). Most interventions were corticosteroids or monoclonal antibodies. All EoE studies assessed patient-reported dysphagia, usually using a non-validated questionnaire. Twenty-two of 23 EoE studies used peak tissue eosinophil count as the primary outcome, usually using a non-validated assessment method, and other immunological markers were only exploratory. Thirteen (57%) EoE studies reported endoscopic outcomes of which six used a validated scoring tool recently recommended as a core outcome for EoE trials. Funding source was not obviously associated with likelihood of an RCT reporting mechanistic versus patient-reported outcomes. Only 3 (12%) RCTs concerned forms of food allergy other than EoE, and they reported on fecal immunological markers and patient-reported outcomes.

CONCLUSIONS

Outcomes measured in clinical trials of EoE and non-IgE-mediated food allergy are heterogeneous and largely non-validated. Core outcomes for EoE have been developed and need to be used in future trials. For other forms of mixed or non-IgE-mediated food allergies, core outcome development is needed to support the development of effective treatments.

SYSTEMATIC REVIEW REGISTRATION

OSF public registry DOI:10.17605/OSF.IO/AZX8S.

[Forsythiaside B inhibits cerebral ischemia/reperfusion-induced oxidative stress injury in mice via the AMPK/DAF-16/FOXO3 pathway]

OBJECTIVE

To study the protective effect of forsythiaside B (FB) against cerebral oxidative stress injury induced by cerebral ischemia/reperfusion (I/R) in mice and explore the underlying mechanism.

METHODS

Ninety C57BL/6 mice were randomized into sham-operated group, middle cerebral artery occlusion (MCAO) model group, and low-, medium and highdose (10, 20, and 40 mg/kg, respectively) FB groups. The expression levels of MDA, ROS, PCO, 8-OHdG, SOD, GSTα4, CAT and GPx in the brain tissue of the mice were detected using commercial kits, and those of AMPK, P-AMPK, DAF-16, FOXO3 and P-FOXO3 were detected with Western blotting. Compound C (CC), an AMPK inhibitor, was used to verify the role of the AMPK pathway in mediating the therapeutic effect of FB. In another 36 C57BL/6 mice randomized into 4 sham-operated group, MCAO model group, FB (40 mg/kg) treatment group, FB+CC (10 mg/kg) treatment group, TTC staining was used to examine the volume of cerebral infarcts, and the levels of ROS and SOD in the brain were detected; the changes in the protein expressions of AMPK, P-AMPK, DAF-16, FOXO3 and P-FOXO3 in the brain tissue were detected using Western blotting.

RESULTS

In mice with cerebral IR injury, treatment with FB significantly reduced the levels of ROS, MDA, PCO and 8-OHdG, increased the activities of antioxidant enzymes SOD, GSTα4, CAT and GPx, and enhanced phosphorylation of AMPK and FOXO3 and DAF-16 protein expression in the brain tissue (P < 0.01). Compared with FB treatment alone, the combined treatment with FB and CC significantly reduced phosphorylation of AMPK and FOXO3, lowered expression of DAF-16 and SOD activity, and increased cerebral infarction volume and ROS level in the brain tissue of the mice (P < 0.01).

CONCLUSION

FB inhibits oxidative stress injury caused by cerebral I/R in mice possibly by enhancing AMPK phosphorylation, promoting the downstream DAF-16 protein expression and FOXO3 phosphorylation, increasing the expression of antioxidant enzymes, and reducing ROS level in the brain tissue.

Preoperative Rehabilitation Is Feasible in the Weeks Prior to Surgery and Significantly Improves Functional Performance

BACKGROUND

Frailty is a multidimensional state of increased vulnerability. Frail patients are at increased risk for poor surgical outcomes. Prior research demonstrates that rehabilitation strategies deployed after surgery improve outcomes by building strength.

OBJECTIVES

Examine the feasibility and impact of a novel, multi-faceted prehabilitation intervention for frail patients before surgery.

DESIGN

Single arm clinical trial.

SETTING

Veterans Affairs hospital.

PARTICIPANTS

Patients preparing for major abdominal, urological, thoracic, or cardiac surgery with frailty identified as a Risk Analysis Index≥30.

INTERVENTION

Prehabilitation started in a supervised setting to establish safety and then transitioned to home-based exercise with weekly telephone coaching by exercise physiologists. Prehabilitation included (a)strength and coordination training; (b)respiratory muscle training (IMT); (c)aerobic conditioning; and (d)nutritional coaching and supplementation. Prehabilitation length was tailored to the 4-6 week time lag typically preceding each participant's normally scheduled surgery.

MEASUREMENTS

Functional performance and patient surveys were assessed at baseline, every other week during prehabilitation, and then 30 and 90 days after surgery. Within-person changes were estimated using linear mixed models.

RESULTS

43 patients completed baseline assessments; 36(84%) completed a median 5(range 3-10) weeks of prehabilitation before surgery; 32(74%) were retained through 90-day follow-up. Baseline function was relatively low. Exercise logs show participants completed 94% of supervised exercise, 78% of prescribed IMT and 74% of home-based exercise. Between baseline and day of surgery, timed-up-and-go decreased 2.3 seconds, gait speed increased 0.1 meters/second, six-minute walk test increased 41.7 meters, and the time to complete 5 chair rises decreased 1.6 seconds(all P≤0.007). Maximum and mean inspiratory and expiratory pressures increased 4.5, 7.3, 14.1 and 13.5 centimeters of water, respectively(all P≤0.041).

CONCLUSIONS

Prehabilitation is feasible before major surgery and achieves clinically meaningful improvements in functional performance that may impact postoperative outcomes and recovery. These data support rationale for a larger trial powered to detect differences in postoperative outcomes.

P–547 Single-cell RNA sequencing identifies molecular regulations associated with poor maturation performance on rescue in vitro matured oocytes

Study question

What is the transcriptome signature associated with rescuein vitro matured (rIVM) oocytes?

Summary answer

GATA–1/CREB1/WNT signaling axis was repressed in rIVM oocytes of poor quality.

What is known already

rIVM aims to produce mature oocytes (MII) for in vitro fertilization (IVF) through IVM of immature oocytes collected from stimulated ovaries. It is less popular due to limited success rate in infertility treatment. Genetic aberrations, cellular stress, and the absence of cumulus cell support in oocytes could account for the failure of rIVM.

Study design, size, duration

We applied single-cell RNA sequencing (scRNA-seq) to capture the transcriptomes of human in vivo (IVO) oocytes (n = 10) from 7 donors and rIVM oocytes (n = 10) from 10 donors, followed by studying the maternal age effect and ovarian responses on rIVM oocyte transcriptomes.

Participants/materials, setting, methods

Human oocytes were collected from donors aged 28–41 years with a body mass index of &lt; 30. RNA extraction, cDNA generation, library construction and sequencing were performed in one preparation. scRNA-seq data were then processed and analyzed. Selected genes in therIVM vs. IVO comparison were validated by quantitative real-time PCR.

Main results and the role of chance

The transcriptome profiles of rIVM/IVO showed distinctive differences. A total of 1559 differentially expressed genes (DEGs, genes with at least two-fold change and adjusted p &lt; 0.05) were found to be enriched in metabolic processes, biosynthesis, and oxidative phosphorylation. Among these DEGs, we identified a repression of WNT/β-catenin signaling in rIVM when compared with IVO oocytes. We found that estradiol level exhibited a significant age-independent correlation with the IVO mature oocyte ratio (MII ratio). rIVM oocytes with higher MII ratio showed over-represented cellular processes such as anti-apoptosis. To further identify targets that contribute to the poor outcomes of rIVM, we compared oocytes collected from young donors with high MII ratio versus donors of advanced maternal age and revealed CREB1was an important regulator in rIVM. Our study identified GATA–1/CREB1/WNT signaling was repressed in both rIVM condition and rIVM oocytes of low-quality.

Limitations, reasons for caution

In the rIVM oocytes of high- and low-quality comparison, the number of samples was limited after data filtering with stringent selection criteria. For the oocyte stage identification, we were unable to predict the presence of oocyte spindle so polar body extrusion was the only indicator.

Wider implications of the findings: This study showed that GATA–1/CREB1/WNT signaling and antioxidant actions were repressed in rIVM condition and was further downregulated in rIVM oocytes of low-quality, providing us the foundation of subsequent follow-up research on human subjects.

Trial registration number

Not applicable

Risk of peanut- and tree-nut-induced anaphylaxis during Halloween, Easter and other cultural holidays in Canadian children

BACKGROUND

It is not established whether the risk of anaphylaxis induced by peanuts or tree nuts in children increases at specific times of the year. We aimed to evaluate the risk of peanut-and tree-nut-induced anaphylaxis during certain cultural holidays in Canadian children.

METHODS

We collected data on confirmed pediatric cases of anaphylaxis presenting to emergency departments in 4 Canadian provinces as part of the Cross-Canada Anaphylaxis Registry. We assessed the mean number of cases per day and incidence rate ratio (IRR) of anaphylaxis induced by unknown nuts, peanuts and tree nuts presenting during each of 6 holidays (Halloween, Christmas, Easter, Diwali, Chinese New Year and Eid al-Adha) versus the rest of the year. We estimated IRRs and 95% confidence intervals (CIs) using Poisson regression.

RESULTS

Data were collected for 1390 pediatric cases of anaphylaxis between 2011 and 2020. Their median age was 5.4 years, and 864 (62.2%) of the children were boys. During Halloween and Easter, there were higher rates of anaphylaxis to unknown nuts (IRR 1.66, 95% CI 1.13-2.43 and IRR 1.71, 95% CI 1.21-2.42, respectively) and peanuts (IRR 1.86, 95% CI 1.12-3.11 and IRR 1.57, 95% CI 0.94-2.63, respectively) compared to the rest of the year. No increased risk of peanut- or tree-nut-induced anaphylaxis was observed during Christmas, Diwali, Chinese New Year or Eid al-Adha. Anaphylaxis induced by unknown nuts, peanuts and tree nuts was more likely in children aged 6 years or older than in younger children.

INTERPRETATION

We found an increased risk of anaphylaxis induced by unknown nuts and peanuts during Halloween and Easter among Canadian children. Educational tools are needed to increase awareness and vigilance in order to decrease the risk of anaphylaxis induced by peanuts and tree nuts in children during these holidays.

Making the GRADE in anaphylaxis management: Toward recommendations integrating values, preferences, context, and shared decision making

OBJECTIVE

To review GRADE (Grading of Recommendations Assessment, Development, and Evaluation) methods and discuss the clinical application of conditional recommendations in clinical guidelines, specifically in the context of anaphylaxis.

DATA SOURCES

Articles that described GRADE, evidence synthesis, evidence to recommendation frameworks, and shared decision making were used to discuss conditional recommendations of the 2020 Anaphylaxis GRADE guideline.

STUDY SELECTIONS

A narrative review detailing concepts of GRADE and approaches to translate conditional recommendations to individualized and contextualized patient care.

RESULTS

GRADE methods encourage a nuanced relationship between certainty of evidence and strength of recommendations. Strength of recommendation must incorporate key factors, including the balance between benefits and harms, patient values and preferences, and resource allocation (costs), with equity, feasibility, and acceptability also often included as considerations. GRADE guidelines provide recommendations that are characterized by directionality (for or against) and strength (strong or conditional). A conditional recommendation is tailored to context and primarily applied through a lens of patient preferences related to the likelihood of outcomes of importance and a shared decision-making approach. Although the 2020 Anaphylaxis GRADE guideline better informs the practice of anaphylaxis prevention through (1) identification and mitigation of risk factors for biphasic anaphylaxis and (2) evaluation of the use of glucocorticoid and/or antihistamine pretreatment, all GRADE recommendations, although directional, are conditional and as such should not be universally applied to every circumstance.

CONCLUSION

Clinical guidelines provide an important opportunity to critically appraise evidence and translate evidence to practice. Patients, practitioners, and policy makers should appreciate the strength of recommendation and certainty of evidence and understand how this affects guideline applicability and implementation.

2019 ARIA Care pathways for allergen immunotherapy

Allergen immunotherapy (AIT) is a proven therapeutic option for the treatment of allergic rhinitis and/or asthma. Many guidelines or national practice guidelines have been produced but the evidence-based method varies, many are complex and none propose care pathways. This paper reviews care pathways for AIT using strict criteria and provides simple recommendations that can be used by all stakeholders including healthcare professionals. The decision to prescribe AIT for the patient should be individualized and based on the relevance of the allergens, the persistence of symptoms despite appropriate medications according to guidelines as well as the availability of good-quality and efficacious extracts. Allergen extracts cannot be regarded as generics. Immunotherapy is selected by specialists for stratified patients. There are no currently available validated biomarkers that can predict AIT success. In adolescents and adults, AIT should be reserved for patients with moderate/severe rhinitis or for those with moderate asthma who, despite appropriate pharmacotherapy and adherence, continue to exhibit exacerbations that appear to be related to allergen exposure, except in some specific cases. Immunotherapy may be even more advantageous in patients with multimorbidity. In children, AIT may prevent asthma onset in patients with rhinitis. mHealth tools are promising for the stratification and follow-up of patients.