Quality and consistency of clinical practice guidelines on the prevention of food allergy and atopic dermatitis: Systematic review protocol

Background and aims

Allergy prevention strategies have gained significant traction as a means to attenuate the growing burden of allergic diseases over the past decade. As the evidence base for primary prevention of food allergy (FA) and atopic dermatitis (AD) is constantly advancing, clinical practice guideline (CPG) recommendations on interventions for FA and AD prevention vary in quality and consistency among professional organizations. We present a protocol for a systematic review of CPGs on primary prevention of FA and AD.

Methods

We will systematically review and appraise all CPGs addressing primary prevention of FA and AD and report our findings according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Electronic databases and manual website searches from January 2011 to March 2021 without language or geographical restrictions, and supplemented by author contact, will generate the list of potentially relevant CPGs to screen. Evaluation of the methodological quality, consistency, and global applicability of shortlisted CPGs will be performed by members of the Allergy Prevention Work Group of the World Allergy Organization (WAO) using the Appraisal of Guidelines for Research and Evaluation (AGREE) II and AGREE-REX (Recommendations EXcellence). instruments. Guideline contents, consistency, and quality of the recommendations will be summarised in tabular and narrative formats. We aim to present consolidated recommendations from international guidelines of the highest methodological quality and applicability, as determined by AGREE II and AGREE-REX.

Dissemination

This systematic review will provide a succinct overview of the quality and consistency of recommendations across all existing CPGs for FA and AD prevention, as well as crucial perspectives on applicability of individual recommendations in different geographical contexts. Results from this systematic review will be reported in a peer-reviewed journal. It will also inform a position statement by WAO to provide a practical framework to guide the development of future guidelines for allergy prevention worldwide.

Prospero registration number

CRD42021265689.

Consensus on DEfinition of Food Allergy SEverity (DEFASE): Protocol for a systematic review

Background and aims

The term “Food Allergy” refers to a complex global health problem with a wide spectrum of severity. However, a uniform definition of severe food allergy is currently missing. This systematic review is the preliminary step towards a state-of-the-art synopsis of the current evidence relating to the severity of IgE-mediated food allergy; it will inform attempts to develop a consensus to define food allergy severity by clinicians and other stakeholders.

Methods

We will undertake a systematic review, which will involve searching international biomedical databases for published studies. Studies will be independently screened against pre-defined eligibility criteria and critically appraised by established instruments. Data will be descriptively and, if possible and applicable, quantitatively synthesised.

Ethics and dissemination

This study does not require any specific ethical approval since it is a systematic review. We plan to report results from this systematic review in a peer reviewed journal. These results will be used to inform the development of an international consensus to define severe food allergy. Author's potential conflicts of interest are clearly stated.

PROSPERO registration number

CRD42020183103.

Blood gene transcript signature profiling in pregnancies resulting in preterm birth: A systematic review

OBJECTIVE

To pursue a systematic review and summarise the current evidence for the potential of transcriptome molecular profiling in investigating the preterm phenotype.

STUDY DESIGN

We systematically reviewed the literature, using readily available electronic databases (i.e. PubMed/Medline, Embase, Scopus and Web of Science) from inception until March 2020 to identify investigations of maternal blood-derived RNA profiling in preterm birth (PTB). Studies were included if circulating coding or non-coding RNA was analysed in maternal blood during pregnancy and/or at delivery. Interventional trials were not included. The primary outcome was the availability of whole genome expression patterns evaluated in pregnancies resulting in preterm deliveries.

RESULTS

A total of 35 articles were included in the final analysis. Most of the studies were conducted in high-income countries and published in the last decade. Apart from spontaneous PTB, a variety of phenotypes leading to preterm delivery were reported. Differences in sampling methods, target gene selection and laboratory protocols severely limited any quantitative comparisons. Most of the studies revealed that gene expression profiling during pregnancy has high potential for identifying women at risk of spontaneous and/or non-spontaneous PTB as early as in the first trimester.

CONCLUSION

Assessing maternal blood-derived transcriptional signatures for PTB risk in pregnant women holds promise as a screening approach. However, longitudinally followed, prospective pregnancy cohorts are lacking. These are relevant for identifying causes leading to PTB and whether prediction of spontaneous PTB or co-morbidities associated with PTB is achievable. More emphasis on widely employed standardised protocols is required to ensure comparability of results.

Can Non-Selective Beta-Blockers (NSBBs) Prevent Enlargement of Small Esophageal Varices in Patients with Cirrhosis? A Meta-analysis

BACKGROUND

Non-selective beta-blockers (NSBBs) are recommended for prophylaxis of first variceal bleeding in patients of cirrhosis with large esophageal varices. However, the data is conflicting whether NSBBs can also prevent growth of small esophageal varices to large size.

AIM

To perform a meta-analysis of the randomized clinical trials comparing NSBBs with placebo for prevention of development of large esophageal varices in patients of cirrhosis with small esophageal varices.

METHODS

The PubMed, EMBASE, Science Direct, and Cochrane library databases were searched for relevant papers. A meta-analysis was performed using risk ratios (RRs) with 95% confidence interval (CI) as the effect sizes.

RESULTS

Overall, 314 trials were initially retrieved from the database searches, of which five randomized controlled trials were included in the meta-analysis. The incidence of development of large varices (RR = 0.91, 95%CI: 0.29-2.86; P = 0.87) was similar between NSBB and placebo groups. However, the heterogeneity among studies was significant (P < 0.01) with an I² of 93%. The incidences of first variceal bleeding (RR = 0.72, 95%CI: 0.25-2.12; P = 0.55) and death (RR = 0.76, 95%CI: 0.50-1.15; P = 0.19) were also similar between NSBB and placebo groups; with no heterogeneity. The incidence of adverse events was significantly higher in the NSBB group compared with the placebo group (RR = 4.66, 95%CI: 1.36-15.91; P = 0.01).

CONCLUSION

The results of this meta-analysis indicate that NSBBs are not effective in preventing growth of small varices and may lead to significant adverse effects. Hence, NSBBs should not be recommended for cirrhotic patients with small varices.