Paediatric allergy diagnosis in primary care is improved by in vitro allergen-specific IgE testing

Allergic Rhinitis in Preschoolers: A Systematic Review of Diagnostics

BACKGROUND

Most studies that seek to analyze the prevalence of allergic rhinitis do not include preschool children and the diagnosis in this age group is difficult.

OBJECTIVE

Identify complementary tests to the diagnosis of allergic rhinitis in preschool children and verify if there is scientific robustness to propose a diagnostic algorithm for this condition in this age group.

METHODS

Systematic review of the literature in four databases: SCIELO, PubMed/MEDLINE, LILACS and SCOPUS. Each article was initially chosen by title, abstract and by the keywords "allergic rhinitis," "diagnosis" and "preschool." Those articles selected entered the complete reading and data extraction phase. The study was registered in the International Prospective Register of Systematic Reviews under number CRD42020207053.

RESULTS

Fourteen articles were suitable for analysis. In the assessment using Quality Assessment of Diagnostic Accuracy Studies - 2, all studies had at least one domain considered "high risk" or "undetermined risk." Seven reports of nasal cytology, seven of specific IgE, four of immediate hypersensitivity skin test, one of nasal nitric oxide, three of total IgE and one of urinary leukotriene E4 were found. Eight articles evaluated more than one diagnostic test.

CONCLUSION

There are no defined criteria for the diagnosis of allergic rhinitis in preschool children. Nasal cytology, serum specific IgE and immediate hypersensitivity skin test were the most used tests. A reliable diagnostic criterion in this age group is necessary so that in the future it is possible to propose a diagnostic algorithm for allergic rhinitis in preschool children.

Allergens sensitization among children with allergic diseases in Shanghai, China: age and sex difference

Background

The distribution of allergens has geographic characteristics. Local epidemiological data provides evidence-based strategies for the prevention and management of allergic diseases. Age and sex differences may exist in the prevalence of sensitivity to various allergens. We investigated the distribution of common allergens in allergic children in Shanghai, southeastern China.

Methods

39,926 children 1 month to 18 years of age diagnosed with allergic diseases were tested for the presence of serum-specific Immunoglobulins E (sIgE) to 17 allergens common to this region, using a reversed enzyme allergosorbent test.

Results

25,757 (64.5%) of the subjects showed elevated sIgE to at least one of the tested allergens. House mite and dust mite were the most common aeroallergens, while egg and milk were the most common food allergens. The most common aeroallergens and food allergens were similar among each allergic disease. By age-group analysis, the positive rates of aeroallergens were higher at older age. Several peaks of sensitization to food allergens were observed in children between 1 and 3 years of age for eggs, milk, nut, crab and shrimp. In addition, the sensitization to beef and mango was highest in children 3–6 years of age. The rate of positive sIgE detection was higher in males than females for all the tested allergens except cockroach, trees and beef. Considering the interplay between sex and ages and other related components (including season, monthly temperature, humidity, air quality index, test rate of patients), the sIgE positive rates of the main aeroallergens increased with age, while the main food allergens decreased; males are more sensitive to several aeroallergens (including dust mite, house mite, cat epithelium, dog epithelium and mulberry).

Conclusions

House mite, dust mite, milk, and egg are major allergens in Shanghai. Children at younger age are more sensitive to food allergens, while increasing overall prevalence of sensitization can be found with increasing age. Boys have higher positive rates of sIgE responses than girls. Knowledge of the prevalence of allergen sensitization in different age groups and sex may help facilitate diagnosis and intervention efforts to mitigate the impact of allergic diseases in this large geographical region. This approach may be extrapolated to other regions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02008-7.

Highly sensitive colorimetric detection of allergies based on an immunoassay using peroxidase-mimicking nanozymes

Nanomaterials that exhibit enzyme-like characteristics, which are called nanozymes, have recently attracted significant attention due to their potential to overcome the intrinsic limitations of natural enzymes, such as low stability and relatively high cost for preparation and purification. In this study, we report a highly efficient colorimetric allergy detection system based on an immunoassay utilizing the peroxidase-mimicking activity of hierarchically structured platinum nanoparticles (H-Pt NPs). The H-Pt NPs had a diameter of 30 nm, and were synthesized by a seed-mediated growth method, which led to a significant amount of peroxidase-like activity. This activity mainly occurs because of the high catalytic power of the Pt element, and the fact that the H-Pt NPs have a large surface area available for catalytic events. The H-Pt NPs were conjugated to an antibody for the detection of immunoglobulin E (IgE) in the analytes; IgE is a representative marker for the diagnosis of allergies. They were then successfully integrated into a conventionally used allergy diagnostic test, the ImmunoCAP diagnostic test, as a replacement for natural signaling enzymes. Using this strategy, total and specific IgE levels were detected within 5 min at room temperature, with high specificity and sensitivity. The practical utility of the immunoassay was also successfully verified by correctly determining the levels of both total and specific IgE in real human serum samples with high precision and reproducibility. The present H-Pt NP-based immunoassay system would serve as a platform for rapid, robust, and convenient analysis of IgE, and can be extended to the construction of diagnostic systems for a variety of clinically important target molecules.

Challenges in the implementation of the EAACI AIT guidelines: A situational analysis of current provision of allergen immunotherapy

PURPOSE

The European Academy of Allergy and Clinical Immunology (EAACI) has produced Guidelines on Allergen Immunotherapy (AIT). We sought to gauge the preparedness of primary care to participate in the delivery of AIT in Europe.

METHODS

We undertook a mixed-methods, situational analysis. This involved a purposeful literature search and two surveys: one to primary care clinicians and the other to a wider group of stakeholders across Europe.

RESULTS

The 10 papers identified all pointed out gaps or deficiencies in allergy care provision in primary care. The surveys also highlighted similar concerns, particularly in relation to concerns about lack of knowledge, skills, infrastructural weaknesses, reimbursement policies and communication with specialists as barriers to evidence-based care. Almost all countries (92%) reported the availability of AIT. In spite of that, only 28% and 44% of the countries reported the availability of guidelines for primary care physicians and specialists, respectively. Agreed pathways between specialists and primary care physicians were reported as existing in 32%-48% of countries. Reimbursement appeared to be an important barrier as AIT was only fully reimbursed in 32% of countries. Additionally, 44% of respondents considered accessibility to AIT and 36% stating patient costs were barriers.

CONCLUSIONS

Successful working with primary care providers is essential to scaling-up AIT provision in Europe, but to achieve this, the identified barriers must be overcome. Development of primary care interpretation of guidelines to aid patient selection, establishment of disease management pathways and collaboration with specialist groups are required as a matter of urgency.

Lactobacillus delbrueckii subsp. bulgaricus CRL 454 cleaves allergenic peptides of β-lactoglobulin

Whey, a cheese by-product used as a food additive, is produced worldwide at 40.7 million tons per year. β-Lactoglobulin (BLG), the main whey protein, is poorly digested and is highly allergenic. We aimed to study the contribution of Lactobacillus delbrueckii subsp. bulgaricus CRL 454 to BLG digestion and to analyse its ability to degrade the main allergenic sequences of this protein. Pre-hydrolysis of BLG by L. delbrueckii subsp. bulgaricus CRL 454 increases digestion of BLG assayed by an in vitro simulated gastrointestinal system. Moreover, peptides from hydrolysis of the allergenic sequences V41-K60, Y102-R124, C121-L140 and L149-I162 were found when BLG was hydrolysed by this strain. Interestingly, peptides possessing antioxidant, ACE inhibitory, antimicrobial and immuno-modulating properties were found in BLG degraded by both the Lactobacillus strain and digestive enzymes. To conclude, pre-hydrolysis of BLG by L. delbrueckii subsp. bulgaricus CRL 454 has a positive effect on BLG digestion and could diminish allergenic reactions.

Sublingual immunotherapy: World Allergy Organization position paper 2013 update

We have prepared this document, "Sublingual Immunotherapy: World Allergy Organization Position Paper 2013 Update", according to the evidence-based criteria, revising and updating chapters of the originally published paper, "Sublingual Immunotherapy: World Allergy Organization Position Paper 2009", available at http://www.waojournal.org. Namely, these comprise: "Mechanisms of sublingual immunotherapy;" "Clinical efficacy of sublingual immunotherapy" - reporting all the data of all controlled trials published after 2009; "Safety of sublingual immunotherapy" - with the recently published Grading System for adverse reactions; "Impact of sublingual immunotherapy on the natural history of respiratory allergy" - with the relevant evidences published since 2009; "Efficacy of SLIT in children" - with detailed analysis of all the studies; "Definition of SLIT patient selection" - reporting the criteria for eligibility to sublingual immunotherapy; "The future of immunotherapy in the community care setting"; "Methodology of clinical trials according to the current scientific and regulatory standards"; and "Guideline development: from evidence-based medicine to patients' views" - including the evolution of the methods to make clinical recommendations.Additionally, we have added new chapters to cover a few emerging crucial topics: "Practical aspects of schedules and dosages and counseling for adherence" - which is crucial in clinical practice for all treatments; "Perspectives and new approaches" - including recombinant allergens, adjuvants, modified allergens, and the concept of validity of the single products. Furthermore, "Raising public awareness about sublingual immunotherapy", as a need for our patients, and strategies to increase awareness of allergen immunotherapy (AIT) among patients, the medical community, all healthcare stakeholders, and public opinion, are also reported in detail.

Recognition of the major cat allergen Fel d 1 through the cysteine-rich domain of the mannose receptor determines its allergenicity

Dendritic cells are professional antigen-presenting cells that are specialized in antigen uptake and presentation. Allergy to cat has increased substantially in recent years and has been shown to be positively associated with asthma. We have recently shown that the mannose receptor (MR), a C-type lectin expressed by dendritic cells, recognizes various glycoallergens from diverse sources and is involved in promoting allergic responses to a major house dust mite allergen in vitro. Here we investigated the potential role of MR in allergic responses to Fel d 1, a major cat allergen. Fel d 1 binding to MR was confirmed by ELISA. Using blocking, gene silencing (siRNA) experiments, and MR knock-out (MR(-/-)) cells, we have demonstrated that MR plays a major role in internalization of Fel d 1 by human and mouse antigen-presenting cells. Intriguingly, unlike other glycoallergens, recognition of Fel d 1 by MR is mediated by the cysteine-rich domain, which correlates with the presence of sulfated carbohydrates in natural Fel d 1. WT and MR(-/-) mice were used to study the role of MR in allergic sensitization to Fel d 1 in vivo. MR(-/-) mice sensitized with cat dander extract and Fel d 1 produced significantly lower levels of total IgE, Fel d 1-specific-IgE and IgG1, the hallmarks of allergic response, compared with WT mice. Our data show for the first time that Fel d 1 is a novel ligand of the cysteine-rich domain of MR and that MR is likely to play a pivotal role in allergic sensitization to airborne allergens in vivo.

Determination of multiple allergen-specific IgE by microfluidic immunoassay cartridge in clinical settings

Our aims were to evaluate the performance of an automated microfluidic immunoassay system for measuring allergen-specific IgE (sIgE) in sera against an established in vitro assay and to assess the system's diagnostic accuracy against objective clinical criteria for identifying sensitization to specific allergens in daily practice of allergy clinics. Using both the automated microfluidic-based immunoassay system (BioIC and ImmunoCAP, we measured sIgE in serum samples from 212 children who visited allergic clinics in two medical centers. Outcomes of skin prick tests (SPT) served as the clinical comparison method. The assay results of targeted allergen of BioIC have a good correlation with ImmunoCAP in the diagnosis of allergen sensitivity by patients' clinical history. When comparing the test results of the sIgE against overall allergens, in either two tests among the three assays performed showed high percentage of agreement between BioIC and ImmunoCAP (77.8%, 95% CI: 72-83.3%) but not with SPT (BioIC 64.9%, 95% CI: 58-72%; ImmunoCAP 67.5%, 95% CI: 61-74%). Using ROC analysis and SPT as quasi-standard, BioIC and ImmunoCAP have nearly the same performance of sensitivity and specificity in the confirmation of SPT results. The total and within one-class agreements of each allergen test result between BioIC and ImmunoCAP ranged between 55.2% and 99.5% with an overall average of 80.9%. Laboratory testing for sIgE can be performed on a fully automated, microfluidic cartridge system with advantages of low sample volume, simultaneously tested allergens, and with diagnostic accuracy for representative allergens equivalent to the semi-automated CAP technology.

The ImmunoCAP Rapid Wheeze/Rhinitis Child test is useful in the initial allergy diagnosis of children with respiratory symptoms

Recurrent upper or lower respiratory symptoms, possibly allergy-related, are very frequent in childhood. It is therefore important that physicians involved in the primary care of these children have an accurate initial diagnostic tool available. In this study, we investigated the value of an in vitro diagnostic device testing 10 common allergens, the ImmunoCAP Rapid Wheeze/Rhinitis Child, for the primary evaluation of allergy. Children with non-infectious upper or lower respiratory symptoms possibly related to allergy were recruited in the primary health care setting of private practices of physician trained in immunology/allergology. The investigators carried out their usual diagnostic work-up including IgE tests, and the ImmunoCAP Rapid test was performed with capillary whole blood in a blinded way to the investigator. The investigators' conclusions on major triggering allergens were compared to the ImmunoCAP Rapid test results. In the whole patient population (n = 185), the sensitivity of the ImmunoCAP Rapid test for unveiling allergic disease was 92% (95% CI: 86-96%) and the specificity 97% (95% CI: 86-100%). Current guidelines for allergy diagnosis suggest screening children with recurrent, moderate/severe diseases for allergies. For children with asthma falling into these categories, sensitivity was 100% (95% CI: 88-100%) and specificity 100% (95% CI: 69-100%); for children with moderate and severe rhinitis sensitivity was 93% (95% CI: 86-97%) and the specificity 100% (95% CI: 79-100%). The ImmunoCAP Rapid test is an accurate test, in particular with regard to high specificity, for diagnosing allergy in children with recurrent respiratory diseases in primary care settings.