Cow's milk protein allergy (CMPA) represents a major health concern in Tunisia, with diagnostic challenges influencing disease prognosis. Molecular allergen testing has emerged as a valuable tool to enhance diagnostic accuracy and predict disease persistence.

This study aims to characterize the clinical and epidemiological features of CMPA in a Tunisian population, with a particular focus on the role of molecular allergens in assessing disease chronicity.

A retrospective analysis was conducted on 262 cases of IgE-mediated CMPA diagnosed at the Pasteur Institute of Tunis between 2020 and 2023. Sensitization to molecular allergens was assessed using ImmunoCAP (Phadia 100).

CMPA symptoms predominantly manifested in infancy (94%, 246/262), with a male predominance (sex ratio: 1.6). Acute reactions were the most frequent presentation (69.9%, 79/113), and polysensitization was common (81%, 212/262), particularly to β-lactoglobulin. Spontaneous resolution occurred in approximately 33% of cases (29/87), with a mean age of 3 years and 8 months. Persistent CMPA was significantly associated with elevated IgE levels to whole milk, β-lactoglobulin, and casein (p < 0.05). ROC curve analysis identified predictive thresholds for disease persistence, including 4.2 kU/L for whole milk-specific IgE and 0.37 kU/L for casein-specific IgE (p = 0.006).

Molecular allergen testing improves CMPA diagnosis and offers critical prognostic insights. The identification of IgE thresholds may facilitate early risk stratification and guide personalized management strategies.

Pollinosis is highly prevalent. Reliable specific IgE tests are needed to identify the causative aeroallergens. This study aims to evaluate the performance of DropScreenTM (DS), a point of care test, by comparing it with that of ViewAllergy39TM, a laboratory test (VA).

Sera from 70 Japanese outpatients with pollinosis (median age: 29.5 years; 35% were men) were used. Qualitative analysis and concordance rate assessment were performed. For allergens with discrepant results between DS and VA, inhibition tests were carried out on relevant samples and allergen component analysis for specific allergens was conducted.

The average positivity rates for the 17 allergens included in the study were 20.8% and 26.6% for DS and VA, respectively. DS positive rate for Japanese cypress was 10-fold lower than that of VA. Clear discrepancies in detection rates between VA and DS were also shown for Japanese cedar, Moth, and A. fumigatus. Inhibition tests on discrepant sera confirmed that VA could accurately measure specific IgE toward these allergens.

DS and VA were not equally effective in reliably detecting specific IgE toward Japanese cypress. This study highlights the importance of understanding the impact of testing performance differences between assays on diagnostic workup and subsequent therapy selection.

Originally native to North America, ragweed has become a pervasive invasive species worldwide over the past century, posing a substantial public health risk as a potent allergen. This review explores the key allergens found in common ragweed, assesses global trends in ragweed sensitization, particularly in China, and examines various therapeutic and biological control methods. There are currently 11 identified ragweed allergens, with Amb a 1 and 11 recognized as the primary triggers. Epidemiological data indicate higher rates of sensitization in North America and Europe, with a growing trend observed in China. Ragweed-induced type I hypersensitivity typically presents as seasonal allergic rhinitis, conjunctivitis, and asthma symptoms. Strategies for managing ragweed allergy include allergen avoidance, pharmacotherapy, and allergen immunotherapy (AIT). Biological control using Ophraella communa and Epiblema strenuana effectively limits ragweed proliferation. Accurate allergen identification and personalized treatment can significantly reduce the health burden associated with ragweed. An in-depth understanding of ragweed sensitization patterns and biological control measures is essential for the long-term prevention of ragweed allergies.

Diagnosis of allergies is mostly based on the patient's clinical history and allergen provocation tests. Determination of specific IgE (sIgE) profiles can be performed to support allergy diagnosis. This is commonly done in vivo by the skin prick test or in vitro with automated systems. Several platforms exist to quantify sIgE levels, but all these methods require access to specific instruments, often delaying the test's results. The IgE luciferase-linked immunosorbent assay (LuLISA) allows bioluminescent quantification of IgE against peanut in microliter samples, but this method awaits extension to other allergens. This study aimed to validate a new method, named LuLIPLEX, for multiplexed bioluminescent detection of sIgE against 20 major molecular allergens.

Quantification of sIgE against 12 recombinant or purified food allergens and eight aeroallergens was performed by LuLIPLEX versus standard IgE detection methods (ImmunoCAP, ISAC, ALEX, or NOVEOS). Multiplexed detection of IgE against these 20 allergens was performed within 45 min using 50 μL of serum, plasma, or whole blood samples.

A head-to-head comparison between LuLIPLEX and standard IgE detection methods showed a high correlation among all allergens tested. sIgE profiles in polysensitized subjects could be determined within 45 min in serum and plasma samples, as well as using a single drop of capillary blood.

LuLIPLEX is a rapid and sensitive method to quantify sIgE levels against multiple allergens. Given that the test is very fast and can be performed on small and inexpensive luminometers, the IgE LuLIPLEX could allow point-of-care testing of sIgE profiles in allergic subjects.

Food safety is crucially linked to the food system, ensuring safe production, handling, and distribution to protect public health. Food allergy has been considered as a public health and food safety issue. Despite being widely regarded as a prevailing strategy for managing food allergies, strict food avoidance faces challenges due to allergen cross-contact in the food supply chain and the potential for inaccurate allergen labeling. Hence, a scientific approach to assess allergen risk in this context is imperative. In this review, a novel approach to managing food allergies, referred to as quantitative food allergen risk assessment, is presented. This discussion covered the evolving concepts and modern analytical approaches. Moreover, this review delves into the current application of quantitative food allergen risk assessment. Finally, a valuable tool for food allergen risk assessment in the food industry, Voluntary Incidental Trace Allergen Labelling (VITAL), was introduced. The establishment of a globally harmonized and standardized quantitative food allergen risk assessment framework could facilitate the promotion of international harmonization of allergen labeling, support food allergic consumers in making safe food choices, and safeguard the health of allergic individuals across various regions and ethnicities. The implementation of food allergen risk assessment could ensure both food supply chain safety and guide the establishment of acceptable allergen cross-contact levels, enhancing food safety and bolstering the integrity and sustainability of the food system.

The purpose of this study is to establish a light-initiated chemiluminescence assay (LiCA) for the quantitative analysis of Humulus scandens pollen-specific IgE (sIgE) antibodies.

The best chemibeads coupling method in detecting Humulus scandens pollen - sIgE was selected. The working concentrations of the antigen-antibody and the reaction buffer were optimized as components of the reaction system. Then the assay performance was evaluated and the results of LiCA were compared with ImmunoCAP methods.

In the range of 0.23 kUA/L to 100.51 kUA/L, LiCA demonstrated good linearity. The coefficients of variation for repeatability and intermediate precision ranged from 5.96% to 8.58% and 7.53% to 11.25%, respectively. The limit of blank (LoB), limit of detection (LoD), and limit of quantitation (LoQ) were determined to be 0.044 kUA/L, 0.086 kUA/L, and 0.11 kUA/L, respectively. Furthermore, LiCA exhibited a statistically significant correlation with ImmunoCAP (r = 0.990).

The established LiCA-based quantitative detection method for Humulus scandens pollen-slgE has good analytical performance and potential clinical application prospects.

Allergic patients are characterized by complex and patient-specific IgE sensitization profiles to various allergens, which are accompanied by different phenotypes of allergic disease. Molecular allergy diagnosis establishes the patient's IgE reactivity profile at a molecular allergen level and has moved allergology into the era of precision medicine. Molecular allergology started in the late 1980s with the isolation of the first allergen-encoding DNA sequences. Already in 2002, the first allergen microarrays were developed for the assessment of complex IgE sensitization patterns. Recombinant allergens are used for a precise definition of personal IgE reactivity profiles, identification of genuine IgE sensitization to allergen sources for refined prescription of allergen-specific immunotherapy and allergen avoidance diagnosis of co- versus cross-sensitization, epidemiologic studies, and prediction of symptoms, phenotypes, and development of allergic disease. For example, molecular IgE sensitization patterns associated with more severe respiratory allergies, severe food allergy, and allergy to honeybee or vespids are already established. The implementation of molecular allergy diagnosis into daily clinical practice requires continuous medical education and training doctors in molecular allergy diagnosis, and may be facilitated by clinical decision support systems such as diagnostic algorithms that may take advantage of artificial intelligence.

Allergen testing has emerged as a pivotal component in prevention and treatment strategies for allergic diseases among children and the utilization of specific IgE (sIgE) through a fully automated chemiluminescent microarray immunoassay (CLMIA) has emerged as a promising trend in the simultaneous detection of multiple allergenic components of children.

The accuracy and reliability of CLMIA were verified using children's serum samples that concentrated on allergens. the allergens. The clinical diagnostic practicability of CLMIA was assessed through comprehensive evaluations including measurements of the limit of detection (LOD), intra-batch, and inter-batch precision, linearity analysis, the cross-contamination rate, and the concordance rate with the Phadia system.

After the optimization process of CLMIA, the LODs for allergens were calculated to be below 0.01 kU/L, demonstrating the high sensitivity of CLMIA. All components exhibited good linearity within the range of 0.1-100.0 kU/L and the coefficient of determinations (R2 > 0.99). The data of intra-batch precision (<10 %) and inter-batch data (<15 %) illustrated the high reproducibility of CLMIA. The cross-contamination rates for allergens (<0.5 %) showed the high accuracy of CLMIA without interfering. The positive concordance rate between CLMIA and the Phadia system exceeds 90 % with a good negative concordance rate (>85 %) and the Kappa coefficients (>0.8), suggesting the close alignment of CLMIA and the Phadia system and showing the satisfactory clinical potential of CLMIA in children's allergy disease.

The application of CLMIA has been promising in allergen testing, especially for detecting multiple allergenic components in children.

The basophil activation test (BAT) has become a major cellular in vitro test for evaluating the allergenic activity of specific IgEs. The impact of the BAT is due to the ability of blood basophil granulocytes to present IgE on the high-affinity FcεRI receptor and to mirror the mast cell response that elicits an acute allergic reaction. The BAT proved to be able to identify allergic patients at risk of reacting to a low dose of the allergen and/or developing life-threatening reactions and thus can significantly improve the current management of allergic patients. However, to improve the diagnostic utility for identifying the allergenic activity of different genuinely sensitizing allergens and lower the procedure and labour requirements, developing a multiplex BAT approach incorporating multiple allergen components would be highly anticipated. Recently, the novel multiplex BAT was described utilizing two major innovative steps. The first step was the fluorescent labeling of allergens. The second step was applying fluorescently labeled allergens in flow cytometry assessment to analyze the activation of basophil subpopulations gated according to the binding of different allergens or to evaluate the fluorescence intensity of multiple allergens on the surface of basophils. These novel cellular multiplex approaches will advance our understanding of IgE-mediated responses. Integration of multiplex BAT, in addition to multiplex IgE assays into practice, will personalize the measurement of allergenic IgE activity and can help estimate the likelihood of clinical relevance and risks for multiple allergens when testing individual allergic patients.

Identification of the molecular culprits of allergic reactions leveraged molecular allergology applications in clinical laboratory medicine. Molecular allergology shifted the focus from complex, heterogeneous allergenic extracts, e.g. pollen, food, or insect venom, towards genetically and immunologically defined proteins available for in vitro diagnosis. Molecular allergology is a precision medicine approach for the diagnosis, stratification, therapeutic management, follow-up and prognostic evaluation of patients within a large range of allergic diseases. Exclusively available for in vitro diagnosis, molecular allergology is nonredundant with any of the current clinical tools for allergy investigation. As an example of a major application, discrimination of genuine sensitization from allergen cross-reactivity at the molecular level allows the proper targeting of the culprit allergen and thus dramatically improves patient management. This review aims at introducing clinical laboratory specialists to molecular allergology, from the biochemical and genetic bases, through immunological concepts, to daily use in the diagnosis and management of allergic diseases.

Allergic fungal rhinosinusitis (AFRS) shares similarities with eosinophilic chronic rhinosinusitis (ECRS), both characterized by intractable nasal polyps. The key distinction lies in the presence of fungal infection within the nasal cavity. While ECRS nasal polyps are known for significant infiltration of M2 macrophages and eosinophils, as well as an increase in high endothelial venule (HEV)-like vessels, these features are less commonly reported in AFRS. This study compared clinicopathological findings between AFRS (n=10), ECRS (n=12), and non-ECRS (n=10) patients' nasal polyps using immunohistochemical analysis for CD163 and CD68 to assess the M2/M1 macrophage ratio, and peripheral lymph node addressin (PNAd) and CD34 to evaluate the proportion of HEV-like vessels. AFRS showed a significantly higher number of CD163-positive M2 macrophages and an increased M2/M1 ratio compared with ECRS. However, the percentage of HEV-like vessels and the number of eosinophils infiltrating the nasal polyps were similar in both AFRS and ECRS. The observed increase in M2 macrophages in AFRS nasal polyps is presumed to be induced by fungal infection in the nasal cavity, in comparison with ECRS. These results highlight the distinctive immunological profiles of AFRS and ECRS, emphasizing the role of macrophage polarization in their pathogenesis.

The specific detection of serum IgE antibodies specific to allergens (sIgE Abs) that can crosslink the plural high-affinity IgE receptor (FcεRIα) molecules on the surface of mast cells or basophils with a multivalent allergen can reduce the false-positive diagnoses observed in chemiluminescent and fluorescence enzyme immunoassays for type-I allergic patients. In this study, we detected sIgE Abs to the egg-allergen ovalbumin (OVA) and the wheat-allergen gluten in the sera of rats sensitized with each allergen using an amplified luminescence proximity homogeneous assay by crosslinking (AlphaCL). OVA and gluten were reacted with each sIgE Ab in the sera. Then, acceptor and donor beads labeled with the human FcεRIα were added to the reacted solution. The luminescence intensity for anti-OVA IgE Abs in the sera with the removal of IgG Abs was observed in five of seven (71.4%) of the sensitized rats, whereas no signals were observed in any of the unsensitized rats. The AlphaCL could also detect anti-gluten sIgE Abs in the sera of sensitized rats, but not of unsensitized rats. In conclusion, we successfully detected sIgE Abs in the sera of rats sensitized to two allergens using the AlphaCL. This detection method has the potential to be used as a new diagnostic tool for type-I allergic patients.

Respiratory sensitization is a complex immunological process eventually leading to hypersensitivity following re-exposure to the chemical. A frequent consequence is occupational asthma, which may occur after long latency periods. Although chemical-induced respiratory hypersensitivity has been known for decades, there are currently no comprehensive and validated approaches available for the prospective identification of chemicals that induce respiratory sensitization, while the expectations of new approach methodologies (NAMs) are high. A great hope is that due to a better understanding of the molecular key events, new methods can be developed now. However, this is a big challenge due to the different chemical classes to which respiratory sensitizers belong, as well as because of the complexity of the response and the late manifestation of symptoms. In this review article, the current information on respiratory sensitization related processes is summarized by introducing it in the available adverse outcome pathway (AOP) concept. Potentially useful models for prediction are discussed. Knowledge gaps and gaps of regulatory concern are identified.

IgE-mediated allergies represent a major health problem in the modern world. Apart from allergen-specific immunotherapy (AIT), the only disease-modifying treatment, researchers focus on biologics that target different key molecules such as allergens, IgE, or type 2 cytokines to ameliorate allergic symptoms. Single-domain antibodies, or nanobodies, are the newcomers in biotherapeutics, and their huge potential is being investigated in various research fields since their discovery 30 years ago. While they are dominantly applied for theranostics of cancer and treatment of infectious diseases, nanobodies have become increasingly substantial in allergology over the last decade. In this review, we discuss the prerequisites that we consider to be important for generating useful nanobody-based drug candidates for treating allergies. We further summarize the available research data on nanobodies used as allergen monitoring and detection probes and for therapeutic approaches. We reflect on the limitations that have to be addressed during the development process, such as in vivo half-life and immunogenicity. Finally, we speculate about novel application formats for allergy treatment that might be available in the future.

Pollen from Salsola kali, i.e., saltwort, Russian thistle, is a major allergen source in the coastal regions of southern Europe, in Turkey, Central Asia, and Iran. S. kali-allergic patients mainly suffer from hay-fever (i.e., rhinitis and conjunctivitis), asthma, and allergic skin symptoms. The aim of this study was to investigate the importance of individual S. kali allergen molecules. Sal k 1, Sal k 2, Sal k 3, Sal k 4, Sal k 5, and Sal k 6 were expressed in Escherichia coli as recombinant proteins containing a C-terminal hexahistidine tag and purified by nickel affinity chromatography. The purity of the recombinant allergens was analyzed by SDS-PAGE. Their molecular weight was determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and their fold and secondary structure were studied by circular dichroism (CD) spectroscopy. Sera from clinically well-characterized S. kali-allergic patients were used for IgE reactivity and basophil activation experiments. S. kali allergen-specific IgE levels and IgE levels specific for the highly IgE cross-reactive profilin and the calcium-binding allergen from timothy grass pollen, Phl p 12 and Phl p 7, respectively, were measured by ImmunoCAP. The allergenic activity of natural S. kali pollen allergens was studied in basophil activation experiments. Recombinant S. kali allergens were folded when studied by CD analysis. The sum of recombinant allergen-specific IgE levels and allergen-extract-specific IgE levels was highly correlated. Sal k 1 and profilin, reactive with IgE from 64% and 49% of patients, respectively, were the most important allergens, whereas the other S. kali allergens were less frequently recognized. Specific IgE levels were highest for profilin. Of note, 37% of patients who were negative for Sal k 1 showed IgE reactivity to Phl p 12, emphasizing the importance of the ubiquitous cytoskeletal actin-binding protein, profilin, for the diagnosis of IgE sensitization in S. kali-allergic patients. rPhl p 12 and rSal k 4 showed equivalent IgE reactivity, and the clinical importance of profilin was underlined by the fact that profilin-monosensitized patients suffered from symptoms of respiratory allergy to saltwort. Accordingly, profilin should be included in the panel of allergen molecules for diagnosis and in molecular allergy vaccines for the treatment and prevention of S. kali allergy.

In many countries, infant vaccination with acellular pertussis (aP) vaccines has replaced use of more reactogenic whole-cell pertussis (wP) vaccines. Based on immunological and epidemiological evidence, we hypothesised that substituting the first aP dose in the routine vaccination schedule with wP vaccine might protect against IgE-mediated food allergy. We aimed to compare reactogenicity, immunogenicity, and IgE-mediated responses of a mixed wP/aP primary schedule versus the standard aP-only schedule.

OPTIMUM is a Bayesian, 2-stage, double-blind, randomised trial. In stage one, infants were assigned (1:1) to either a first dose of a pentavalent wP combination vaccine (DTwP-Hib-HepB, Pentabio PT Bio Farma, Indonesia) or a hexavalent aP vaccine (DTaP-Hib-HepB-IPV, Infanrix hexa, GlaxoSmithKline, Australia) at approximately 6 weeks old. Subsequently, all infants received the hexavalent aP vaccine at 4 and 6 months old as well as an aP vaccine at 18 months old (DTaP-IPV, Infanrix-IPV, GlaxoSmithKline, Australia). Stage two is ongoing and follows the above randomisation strategy and vaccination schedule. Ahead of ascertainment of the primary clinical outcome of allergist-confirmed IgE-mediated food allergy by 12 months old, here we present the results of secondary immunogenicity, reactogenicity, tetanus toxoid IgE-mediated immune responses, and parental acceptability endpoints. Serum IgG responses to diphtheria, tetanus, and pertussis antigens were measured using a multiplex fluorescent bead-based immunoassay; total and specific IgE were measured in plasma by means of the ImmunoCAP assay (Thermo Fisher Scientific). The immunogenicity of the mixed schedule was defined as being noninferior to that of the aP-only schedule using a noninferiority margin of 2/3 on the ratio of the geometric mean concentrations (GMR) of pertussis toxin (PT)-IgG 1 month after the 6-month aP. Solicited adverse reactions were summarised by study arm and included all children who received the first dose of either wP or aP. Parental acceptance was assessed using a 5-point Likert scale. The primary analyses were based on intention-to-treat (ITT); secondary per-protocol (PP) analyses were also performed. The trial is registered with ANZCTR (ACTRN12617000065392p). Between March 7, 2018 and January 13, 2020, 150 infants were randomised (75 per arm). PT-IgG responses of the mixed schedule were noninferior to the aP-only schedule at approximately 1 month after the 6-month aP dose [GMR = 0·98, 95% credible interval (0·77 to 1·26); probability (GMR > 2/3) > 0·99; ITT analysis]. At 7 months old, the posterior median probability of quantitation for tetanus toxoid IgE was 0·22 (95% credible interval 0·12 to 0·34) in both the mixed schedule group and in the aP-only group. Despite exclusions, the results were consistent in the PP analysis. At 6 weeks old, irritability was the most common systemic solicited reaction reported in wP (65 [88%] of 74) versus aP (59 [82%] of 72) vaccinees. At the same age, severe systemic reactions were reported among 14 (19%) of 74 infants after wP and 8 (11%) of 72 infants after aP. There were 7 SAEs among 5 participants within the first 6 months of follow-up; on blinded assessment, none were deemed to be related to the study vaccines. Parental acceptance of mixed and aP-only schedules was high (71 [97%] of 73 versus 69 [96%] of 72 would agree to have the same schedule again).

Compared to the aP-only schedule, the mixed schedule evoked noninferior PT-IgG responses, was associated with more severe reactions, but was well accepted by parents. Tetanus toxoid IgE responses did not differ across the study groups.

Trial registered at the Australian and New Zealand Clinical 207 Trial Registry (ACTRN12617000065392p).

The clinical significance of newly available platforms for specific IgE measurement must be evaluated. However, data are lacking for NOVEOS (Hycor), especially for food allergens.

We compared the technical and clinical performance of two platforms (ImmunoCAP and NOVEOS) to measure specific IgE to 10 food allergens.

Sera from 289 clinically characterized patients were tested for IgE specific for six food allergen extracts (egg white, cow's milk, peanut, hazelnut, fish, and shrimp) and four molecular allergens (Gal d 1, Bos d 8, Ara h 2, and Cor a 14). Specific IgE measurements were carried out using ImmunoCAP and NOVEOS methods. Food allergy diagnoses were established according to international guidelines.

A strong correlation (ρ > 0.9) was present between the two platforms whereas specific IgE concentrations measured with NOVEOS were consistently lower (mean, -15%) than with ImmunoCAP. NOVEOS and ImmunoCAP provided similar overall odds ratios and relative risks for food allergy diagnosis with both allergen extracts and molecular allergens. When all 10 allergens were considered, NOVEOS provided better receiver operating characteristic curves (P = .04). Finally, we found that the most discordant results were observed with hazelnut and peanut extracts and were related to cross-reactive carbohydrate determinants for these two with ImmunoCAP.

Specific IgE determination by either ImmunoCAP or NOVEOS (odds ratios of allergy, 25.1 or 33.0, respectively) is highly informative regarding the risk of allergy in the selected population. The NOVEOS platform presents the advantage of being less affected by unwanted reactivity owing to carbohydrate determinant-specific IgE while requiring a 10-fold lower test sample volume.

The in vitro specific IgE (sIgE) assays now commonly used in clinical laboratories are not only time-consuming and expensive but also require many serum samples. To address these limitations, a novel fluorescent microsphere-based multiplex flow cytometric immunoassay was developed. This innovative assay enables rapid and simultaneous quantitative detection of multiple allergen-sIgE antibodies.

To establish a new method for the simultaneous quantitative detection of 6 allergen-sIgE antibodies based on fluorescence multiplex flow cytometry.

Six different encoded fluorescent microspheres were selected to covalently couple 6 allergens, and their antigen-coupling activities were verified. After optimizing the multiplexing procedure and reaction conditions, including the concentration of microspheres encapsulated by allergens, reaction temperature, and reaction time, standard curves were established to quantify the 6 allergen-sIgE, and their performance was evaluated according to clinical guidelines.

The chosen analytical mode was optimized for the detection of the 6 allergens-sIgE for 70 minutes. The established coefficients of variation for multiplex flow cytometry reproducibility and intermediate precision were less than 10%. Linear regression analysis showed a highly significant quantitative correlation between the results of the multiple analyses of Dermatophagoides pteronyssinus, Dermatophagoides farinae, Artemisia, and cat hair allergens and ImmunoCAP (Thermo Fisher Scientific): the r2 values ranged from 0.85 to 0.97 (P < .0001). In addition, there was a high correlation between the results of the multiplex analysis of dog hair allergens and the capture enzyme-linked immunosorbent assay (r2 = 0.92, P < .0001).

A high-throughput system called multiplex flow cytometry has been developed for the simultaneous detection of 6 inhalant allergens. The method has the advantage of being rapid and using less serum. Furthermore, it has the potential to be expanded to include other allergens and biologic agents.

The food allergy (FA) entity went through a long difficult road which led to much delay in its recognition. After long periods of denial and misdiagnosis, it attained its current designation as food hypersensitivity or allergy. This review will briefly address the evolution of the FA entity from the early BC era until our 21st century and highlight the milestones in the main aspects of diagnosis, treatment, prevention, and research. A great recognition of the allergy specialty was gained by the discovery of its main mediator -immunoglobulin E in 1967 - which also helped in classifying FA into IgE-mediated (immediate-type) and non-IgE-mediated. The cause of the increasing prevalence during the past few decades may be attributed to an increased food consumption and the consequences of modern lifestyle (the hygiene hypothesis). In addition to a skillful medical history-taking, helpful tests have been developed involving the skin or blood. The scratch test was modified to the prick test and in certain instances prick-by-prick. The use of intradermal test has been markedly reduced. Blood testing began by measuring specific-IgE antibodies (sIgE) in the serum using the radioallergosorbent test which went through multiple modifications to avoid radioisotope material and increase the test's sensitivity. The test was advanced to measure sIgE to individual allergen components. Recently, cellular tests were developed in the form of basophil activation or mast cell activation. In most cases, FA needs verification by appropriately-designed challenge testing. Regarding treatment, strict avoidance remains the basic approach. Certain food-labeling regulations led to some improvement in the problem of hidden food allergens but more is desired. Recently some protocols for oral immunotherapy (OIT) showed reasonable safety and efficacy in preventing reactions to accidental exposures. The protocol for peanut has been approved in the United States and other foods are expected to follow. Epicutaneous immunotherapy showed higher safety and promising efficacy. Sublingual immunotherapy might follow as well. Studies on the use of certain biologicals, alone or in combination of OIT, showed promising findings. Very recently, omalizumab was approved in the United States for patients with multiple FA. A major change in the strategy of prevention is the benefit of introducing allergenic foods at an early age (4-6 months). Research on FA markedly flourished in recent decades with increasing numbers of investigators, funding, publications, and education. Despite the major strides, still more awaits exploration with expected better understanding and practice of FA.

There are few studies concerning the impact of serum vitamin D status on the risk of allergen sensitization and atopic dermatitis (AD) during early childhood.

Children with AD and age-matched healthy controls (HC) were prospectively enrolled at age 0.5, 2, and 4 years. Serum 25-hydroxyvitamin D (25[OH]D) level was measured using Elecsys Vitamin D Total assay. The study utilized the ImmunoCAP assay to analyze specific IgE for food and inhalant allergens, along with total serum IgE levels. It explored the connection between vitamin D levels and allergen sensitization, as well as their influence on AD at different ages.

A total of 222 children including 95 (59 AD and 36 HC), 66 (37 AD and 29 HC), and 61 (32 AD and 29 HC) children were classified at age 0.5, 2, and 4 years, respectively. In children with AD, there was a significantly lower vitamin D level at age 2 and 4, but a significantly higher prevalence of food and mite sensitization at all ages in comparison with HC (P < 0.001). Vitamin D level was found to be inversely related to the prevalence of allergen sensitization at age 4 (P < 0.05). However, vitamin D level appeared to have high importance for allergen sensitization at all ages and AD at age 2 and 4 years.

Vitamin D deficiency is strongly associated with heightened prevalence of allergen sensitization, potentially increasing the susceptibility to AD in early childhood.

To establish a new method for quantitative detection of house dust mite (HDM)-sIgE based on light-initiated chemiluminescence assay (LiCA).

The assay was established after optimizing the reaction conditions, and the assay performance was evaluated according to the clinical guidelines. Further, the results of LiCA were compared with those from the ELISA and ImmunoCAP methods.

Coefficients of variation for repeatability ranged from 4.22% to 7.69%, and intermediate precision from 8.38% to 10.34%. The limit of blank (LoB), limit of detection (LoD), and limit of quantitation (LoQ) were 0.066 kUA/L, 0.165 kUA/L, and 0.171 kUA/L, respectively. The coefficient of correlation (r) between the results of LiCA and ELISA was 0.9263, and the r between the results of LiCA and ImmunoCAP was 0.8870.

A HDM-sIgE quantitation assay based on LiCA was established, which could be used as a new reliable analytical tool for the determination of HDM-sIgE.

In vitro specific IgE (sIgE) testing has become an important tool for the diagnosis of IgE-mediated allergic diseases. Current methods used to detect allergen sIgE are time consuming and/or expensive. Therefore, a new method was developed for rapid quantitative detection of cat dander-sIgE antibody based on homogeneous chemiluminescence immunoassay.

Selection of chemibeads with different chemical groups, and the best Light-initiated chemiluminescence assay (LiCA) analytical mode for cat dander-sIgE detection. To validate and eliminate the interference of IgE on the detection of cat dander-sIgE, concentration of biotinylated anti-human IgE antibody was optimized. For quantification of cat dander-sIgE, a calibration curve was established, and the performance of the assay was evaluated according to clinical guidelines.

Indirect LiCA is the best mode of analysis and biotinylated anti-human IgE antibody at a dilution ratio of 1:250 minimizes IgE interference. The coefficient of variation of the developed LiCA was 1.49% to 4.66%, with an intermediate precision of 6.90% to 8.21%. The LoB, LoD, and LoQ of the assay were 0.023 kUA/L, 0.056 kUA/L and 0.185 kUA/L. The coefficient of correlation (r) between LiCA and ImmounoCAP was 0.9478.

A cat dander-sIgE quantitation assay based on homogeneous chemiluminescence immunoassay was established, which could be a new reliable analytical tool for the determination of cat dander-sIgE.

The symptoms of celery allergy are mainly presented as oral allergy symptom, but there are several case reports of patients who experienced anaphylaxis. Defensin (Api g 7), as a novel allergen in celery root, was described in 2022 r. The female patient had a history of several episodes of dyspnea and cough, associated with ingestion of spice mixes containing dried celery. Up to the point of hospitalization, there were no objective tests, either sIgE or skin prick tests, that would confirm celery sensitization. During hospitalization, patient had a positive double-blind placebo-controlled food challenge with cooked celery. The patient was sensitized to mugwort defensin Art v 1. An inhibition assay with celery allergen extract was performed to prove cross-sensitization between Art v 1 and celery allergen responsible for symptoms in the patient. In conclusion, Api g 7 is an important celery allergen that can be responsible for severe reactions. Its cross-reactivity with Art v 1 is characteristic. Negative diagnostic tests with celery do not exclude Api g 7 sensitization.

More than 10% of the world's population suffers from an immunoglobulin E (IgE)-mediated allergy to cats which is accompanied mainly by respiratory symptoms such as rhinitis and asthma. Several cat allergen molecules have been identified, but their allergenic activity has not been investigated in depth. Purified cat allergen molecules (Fel d 1, Fel d 2, Fel d 3, Fel d 4, Fel d 6, Fel d 7 and Fel d 8) were characterized via mass spectrometry and circular dichroism spectroscopy regarding their molecular mass and fold, respectively. Cat-allergen-specific IgE levels were quantified via ImmunoCAP measurements in IgE-sensitized subjects with (n = 37) and without (n = 20) respiratory symptoms related to cat exposure. The allergenic activity of the cat allergens was investigated by loading patients' IgE onto rat basophils expressing the human FcεRI receptor and studying the ability of different allergen concentrations to induce β-hexosaminidase release. Purified and folded cat allergens with correct masses were obtained. Cat-allergen-specific IgE levels were much higher in patients with a respiratory allergy than in patients without a respiratory allergy. Fel d 1, Fel d 2, Fel d 4 and Fel d 7 bound the highest levels of specific IgE and already-induced basophil degranulation at hundred-fold-lower concentrations than the other allergens. Fel d 1, Fel d 4 and Fel d 7 were recognized by more than 65% of patients with a respiratory allergy, whereas Fel d 2 was recognized by only 30%. Therefore, in addition to the major cat allergen Fel d 1, Fel d 4 and Fel d 7 should also be considered to be important allergens for the diagnosis and specific immunotherapy of cat allergy.

Detection of allergen-specific immunoglobulin E (IgE) antibodies (Abs) in serum would allow for screening of the causative allergen in patients with type-I allergy. In this study, we developed a new assay method to detect allergen-specific IgE Abs, which involved crosslinking the plural FcεRIα molecules with an allergen and detection using an amplified luminescence proximity homogeneous assay (AlphaCL). First, the allergen concentration, bead concentrations, and incubation time were optimized for the detection of anti-2,4-dinitrophenyl (DNP) IgE Abs in buffer. Under optimal conditions, AlphaCL was able to detect DNP-specific IgE Abs in simulated human serum at levels comparable to those in serum from type-I allergic patients. When AlphaCL was used to detect anti-DNP IgE Abs, no signal counts were obtained with the monovalent allergen 2,4-dinitrophenylated poly-γ-glutamic acid, whereas high signal counts were obtained with the multivalent allergen DNP-BSA. This confirmed that AlphaCL could specifically detect allergen-specific IgE Abs with the ability to crosslink a multivalent allergen. In summary, we have established a new assay model using AlphaCL to detect allergen-specific IgE Abs with FcεRIα crosslinking ability in human serum. This simple and practical assay model may be applied as a new diagnostic tool for patients with type-I allergy.

Staphylococcus aureus enterotoxins (SE) may act as superantigens and induce an intense T-cell activation, causing local production of polyclonal IgE and resultant eosinophil activation.

To assess whether asthma with sensitization to SE but not to common aeroallergens (AAs) displays different inflammatory characteristics.

We conducted a prospective study on a series of 110 consecutive patients with asthma recruited from the University Asthma Clinic of Liège. We compared clinical, functional, and inflammatory characteristics of this general population of patients with asthma categorized into 4 groups according to sensitization to AAs and/or SE. We also compared sputum supernatant cytokines in patients sensitized to SE or not.

Patients with asthma sensitized only to AAs represented 30%, while 29% were sensitized to both AAs and SE. One-fifth of the population had no specific IgE. Sensitization to SE but not to AA (21%) was associated with later onset of disease, higher rate of exacerbations, nasal polyps, and more severe airway obstruction. As for airway type 2 biomarkers, patients presenting with specific IgE against SE displayed higher fractional exhaled nitric oxide, sputum IgE, and sputum IL-5 levels but not IL-4. We confirm that the presence of specific IgE against SE is associated with elevated serum IgE to levels well above those observed in patients sensitized only to AAs.

Our study suggests that asthma specialists should measure specific IgE against SE during the phenotyping process because it may allow the identification of a subgroup of patients with more asthma exacerbations, more nasal polyposis and chronic sinusitis, lower lung function, and more intense type 2 inflammation.

The number of people suffering from allergies is increasing worldwide every year. With the prevalence of domestic animals, especially dogs, allergens associated with them can be found ubiquitously, thereby increasing the risk of anaphylaxis in sensitized individuals. Currently, there are 8 known dog allergens, but not all of them have been thoroughly studied. The commonly used skin prick tests often fall short and fail to provide a comprehensive assessment of a patient's condition, thus making allergy diagnosis challenging. Fortunately, the introduction of new allergy diagnostic methods has made it possible to accurately identify clinically significant allergens for patients. These findings can then be used to prescribe appropriate therapy or provide specific recommendations to the patients. This review focuses on the most important dog allergens and modern allergy diagnostic techniques that are gradually being incorporated into medical practice, thus expanding the capabilities of allergists.

Immunoglobulin-E(IgE)-mediated hypersensitivity to cow's milk allergens is a frequent cause of severe and life-threatening anaphylactic reactions. Besides case histories and controlled food challenges, the detection of the IgE antibodies specific to cow's milk allergens is important for the diagnosis of cow-milk-specific IgE sensitization. Cow´s milk allergen molecules provide useful information for the refined detection of cow-milk-specific IgE sensitization.

A micro-array based on ImmunoCAP ISAC technology was developed and designated milk allergen micro-array (MAMA), containing a complete panel of purified natural and recombinant cow's milk allergens (caseins, α-lactalbumin, β-lactoglobulin, bovine serum albumin-BSA and lactoferrin), recombinant BSA fragments, and α-casein-, α-lactalbumin- and β-lactoglobulin-derived synthetic peptides. Sera from 80 children with confirmed symptoms related to cow's milk intake (without anaphylaxis: n = 39; anaphylaxis with a Sampson grade of 1-3: n = 21; and anaphylaxis with a Sampson grade of 4-5: n = 20) were studied. The alterations in the specific IgE levels were analyzed in a subgroup of eleven patients, i.e., five who did not and six who did acquire natural tolerance.

The use of MAMA allowed a component-resolved diagnosis of IgE sensitization in each of the children suffering from cow's-milk-related anaphylaxis according to Sampson grades 1-5 requiring only 20-30 microliters of serum. IgE sensitization to caseins and casein-derived peptides was found in each of the children with Sampson grades of 4-5. Among the grade 1-3 patients, nine patients showed negative reactivity to caseins but showed IgE reactivity to alpha-lactalbumin (n = 7) or beta-lactoglobulin (n = 2). For certain children, an IgE sensitization to cryptic peptide epitopes without detectable allergen-specific IgE was found. Twenty-four children with cow-milk-specific anaphylaxis showed additional IgE sensitizations to BSA, but they were all sensitized to either caseins, alpha-lactalbumin, or beta-lactoglobulin. A total of 17 of the 39 children without anaphylaxis lacked specific IgE reactivity to any of the tested components. The children developing tolerance showed a reduction in allergen and/or peptide-specific IgE levels, whereas those remaining sensitive did not.

The use of MAMA allows for the detection, using only a few microliters of serum, of IgE sensitization to multiple cow's milk allergens and allergen-derived peptides in cow-milk-allergic children with cow-milk-related anaphylaxis.

Food allergy is common in the Mediterranean, especially concerning lipid transfer proteins (LTPs) allergy. LTPs are widespread plant food allergens in fruits, vegetables, nuts, pollen, and latex. Also, LTPs are prevalent food allergens in the Mediterranean area. They can sensitize via the gastrointestinal tract and cause a wide range of conditions: from mild reactions, such as oral allergy syndrome, to severe reactions, such as anaphylaxis. LTP allergy in the adult population is well described in the literature, concerning both the prevalence and clinical characteristics. However, there is poor knowledge about its prevalence and clinical manifestation in children living in the Mediterranean.

This study, including 800 children aged from 1 to 18 years, investigated the prevalence of 8 different molecules of nonspecific LTP over time in an Italian pediatric population visited over the last 11 years.

About 52% of the test population was sensitized to at least one LTP molecule. For all the LTPs analyzed, sensitization increased over time. In particular, using the years 2010 through 2020 as a comparison, the major increases were observed for the LTPs of the English walnut Jug r 3, the peanut Ara h 9, and the plane tree Pla a 3 (about 50%); the increase of the LTP of the Hazelnut Cor a 8 was about 36%, and that of the LTP of the artemisia Art v 3 was approximately 30%.

The latest evidence in the literature indicates an increase in food allergy prevalence in the general population, including children. Therefore, the present survey represents an interesting perspective about the pediatric population of the Mediterranean area, exploring the trend of LTP allergy.

House dust mite (HDM) allergy belongs to the most important allergies and affects approximately 65-130 million people worldwide. Additionally, untreated HDM allergy may lead to the development of severe disease manifestations such as atopic dermatitis or asthma. Diagnosis and immunotherapy of HDM allergic patients are well established but are often hampered by the use of mite extracts that are of bad quality and lack important allergens. The use of individual allergens seems to be a promising alternative to natural allergen extracts, since they represent well-defined components that can easily be produced and quantified. However, a thorough characterization of the individual allergens is required to determine their clinical relevance and to identify those allergens that are required for correct diagnosis of HDM allergy and for successful immunotherapy. This review gives an update on the individual HDM allergens and their benefits for diagnosis and immunotherapy of HDM allergic patients.

To accurately map the B-cell linear epitopes of lysozyme (LYS) in eggs, five bioinformatics tools were first used to obtain the mimotopes. Afterward, based on the Chinese egg-allergic sera samples screened by the indirect enzyme-linked immunosorbent, the epitopes possessing the capability of binding to IgG/IgE were mapped at both pooled and individual levels by using overlapping peptides covering the complete amino acid sequence of LYS. Six B-cell linear epitopes and two dominant B-cell linear epitopes that could bind to LYS-sIgG were mapped for the first time. Seven IgE-binding epitopes and three dominant IgE-binding epitopes were also obtained. Furthermore, AA31-34 and AA88-91 were the shared dominant epitopes of LYS-sIgG and LYS-sIgE at pooled and individual levels. Overall, the mapped B-cell linear epitopes filled in the gaps in the study of LYS epitopes, and the results may provide theoretical support for the following immunotherapy of egg allergy.

The clinical presentation of cat and dog allergy vary from discomfort caused by rhinoconjuncitivitis to severe asthma. Exposure to allergens from these animals is ubiquitous and allergic sensitization to cat or dog affect up to 25% of all children and adults, but allergic sensitization does not always cause symptoms. The introduction of molecular-based allergy diagnostics has improved the possibility to characterize the allergic patient in greater detail. However, the full clinical potential of using molecular allergology in the diagnosis, characterization and treatment of patients with allergy to cats and dogs has not yet been established, although significant progress has been made during the last decade, which will be reviewed in detail in this paper.

Allergen distribution has obvious geographical characteristics. Understanding local epidemiological data may provide evidence-based strategies for the prevention and management of disease. We investigated the distribution of allergen sensitization in patients with skin diseases in Shanghai, China.

Data from tests for serum-specific immunoglobulin E were collected from 714 patients with three skin diseases who visited the Shanghai Skin Disease Hospital from January 2020 to February 2022. The prevalence of 16 allergen species, as well as age, sex, and disease-group differences in allergen sensitization, were investigated.

Dermatophagoides farinae and Dermatophagoides pteronyssinus were the most common aeroallergen species to cause allergic sensitization in patients with skin diseases, whereas shrimp and crab were the most common food-allergen species. Children were more susceptible to various allergen species. With regard to sex differences, males were sensitized to more allergen species than females. Patients suffering from atopic dermatitis were sensitized to more allergenic species than patients with non-atopic eczema or urticaria.

Allergen sensitization in patients with skin diseases in Shanghai differed by age, sex, and disease type. Knowing the prevalence of allergen sensitization across age, sex, and disease type may help facilitate diagnostic and intervention efforts, and guide the treatment and management of skin diseases in Shanghai.

Ragweed (Ambrosia artemisiifolia) pollen is a major endemic allergen source responsible for severe allergic manifestations in IgE-sensitized allergic patients. It contains the major allergen Amb a 1 and cross-reactive allergen molecules, such as the cytoskeletal protein profilin, Amb a 8 and calcium-binding allergens Amb a 9 and Amb a 10. To assess the importance of Amb a 1, profilin and calcium-binding allergen, the IgE reactivity profiles of clinically well-characterized 150 ragweed pollen-allergic patients were analysed regarding specific IgE levels for Amb a 1 and cross-reactive allergen molecules by quantitative ImmunoCAP measurements, IgE ELISA and by basophil activation experiments. By quantifying allergen-specific IgE levels we found that Amb a 1-specific IgE levels accounted for more than 50% of ragweed pollen-specific IgE in the majority of ragweed pollen-allergic patients. However, approximately 20% of patients were sensitized to profilin and the calcium-binding allergens, Amb a 9 and Amb a 10, respectively. As shown by IgE inhibition experiments, Amb a 8 showed extensive cross-reactivity with profilins from birch (Bet v 2), timothy grass (Phl p 12) and mugwort pollen (Art v 4) and was identified as a highly allergenic molecule by basophil activation testing. Our study indicates that molecular diagnosis performed by the quantification of specific IgE to Amb a 1, Amb a 8, Amb a 9 and Amb a 10 is useful to diagnose genuine sensitization to ragweed pollen and to identify patients who are sensitized to highly cross-reactive allergen molecules present in pollen from unrelated plants, in order to enable precision medicine-based approaches for the treatment and prevention of pollen allergy in areas with complex pollen sensitization.