Food-Pollen Cross-Reactivity and its Molecular Diagnosis in China.

PURPOSE OF REVIEW: Plant-derived foods are one of the most common causative sources of food allergy in China, with a significant relationship to pollinosis. This review aims to provide a comprehensive overview of this food-pollen allergy syndrome and its molecular allergen diagnosis to better understand the cross-reactive basis. RECENT FINDINGS: Food-pollen cross-reactivity has been mainly reported in Northern China, Artemisia pollen is the major related inhalant source, followed by tree pollen (Betula), while grass pollen plays a minor role. Pollen allergy is relatively low in Southern China, with allergies to grass pollen being more important than weed and tree pollens. Rosaceae fruits and legume seeds stand out as major related allergenic foods. Non-specific lipid transfer protein (nsLTP) has been found to be the most clinically relevant cross-reacting allergenic component, able to induce severe reactions. PR-10, profilin, defensin, chitinase, and gibberellin-regulated proteins are other important cross-reactive allergen molecules. Artemisia pollen can induce allergenic cross-reactions with a wide range of plant-derived foods in China, and spring tree pollens (Betula) are also important. nsLTP found in both pollen and plant-derived food is considered the most significant allergen in food pollen cross-reactivity. Component-resolved diagnosis with potential allergenic proteins is recommended to improve diagnostic accuracy and predict the potential risk of causing allergic symptoms.

AIT 2023: Current innovation and future outlook.

Although used for over 100 years, allergen immunotherapy (AIT) is still an indispensable tool in modern allergy managemen20t due to its potential to cure allergic diseases. Its current rapid development through the application of personalized and precision medicine approaches is strongly supported by advances in mHealth, component-resolved diagnosis (CRD)-based diagnostics, validation of novel biomarkers, advanced data management, and development of novel preparations. This review summarizes the key advances in the field and shows the perspectives for further development of next-generation AIT treatments.

Major Grass Pollen Allergen Components and Cross-Reactive Carbohydrate Determinants in Mugwort-Sensitized Child Patients With Allergic Respiratory Disease in Western China.

Mugwort is a common pollen allergen in western China, and this study aimed to investigate the patterns of molecular sensitization to major grass pollen allergens (mugwort, ragweed, bermuda grass, and timothy grass) and cross-reactive carbohydrate determinants (CCD) in children who were sensitized to mugwort in western China. Serum-specific IgE (sIgE) of major allergen components and CCD were detected among 121 mugwort SPT-positive children via the EUROBlotMaster system if the mugwort-sIgE was positive (MSP). A CCD inhibition test was further performed on the serum of patients with positive CCD-sIgE. Latent class analysis was used to identify the patterns of potential sensitization to major grass pollen allergens. Of a total of 100 patients with mugwort-sIgE positive (MSP), 52.0, 41.0, and 31.0% of them were positive to Art v 1, Art v 3, and Art v 4, respectively. An optimal model with three latent classes was determined using grass pollen allergens, components, and CCD. The sensitization patterns can be summarized as (1) MSP and cosensitized to ragweed, bermuda grass, and timothy grass (23.74%); (2) MSP and cosensitized to Art v 1 (54.08%); (3) MSP and cosensitized to Art v 4, Cyn d 12, Phl p 12 (22.18%). Additionally, CCD sIgE levels had a significant positive correlation with ragweed, bermuda grass, and timothy grass (P < 0.05), and CCD-Inhibitor can highly inhibit the above allergens sIgE. Our findings suggest that Art v 4 was the typical cross-reaction component of mugwort, which is cosensitized to Phl p 12 and Cyn d 12. A wide cross-reaction among ragweed, bermuda grass, and timothy grass caused by CCD was observed.

Molecular Allergy Diagnosis in Clinical Practice: Frequently Asked Questions.

Considerable progress has been made in the field of molecular biology in recent years, enabling the study of sensitization to the individual components of an allergenic source, a practice that has been termed molecular allergy diagnosis (MD) or component-resolved diagnosis (CRD). The present review provides the clinician with a practical approach to the use of MD by answering questions frequently asked by physicians on how MD can help improve the diagnosis of allergy in daily clinical practice. The article is divided into 3 sections. First, we provide a brief review of the importance for the clinician of knowing the main allergens in the different allergenic sources, their structure, and their in vitro cross-reactivity before approaching MD (section A). Second, we review the usefulness of MD in clinical practice (section B) and answer frequently asked questions on the subject. Finally, section C addresses the interpretation of MD and its integration with other tools available for the diagnosis of allergy.

Evaluation and predictive value of IgE responses toward a comprehensive panel of house dust mite allergens using a new multiplex assay: a real-life experience on an Italian population.

Summary: Background. House dust mites (HDM) are among the most important allergen sources worldwide, representing a major cause of perennial allergic rhinitis and asthma. Aim. To evaluate the prevalence of IgE responses towards a comprehensive panel of HDM allergens and to evaluate the implications of molecular sensitization profiles on respiratory symptoms. Methods. 155 consecutive HDM-allergic patients (mean age: 27.5 years; range: 1-62; female: 63), 86 affected by rhinitis and 68 by asthma, were enrolled. Specific IgE reactivity to Der f 1, Der p 1, Der f 2, Der p 2, Der p 5, Der p 7, Der p 10, Der p 11, Der p 20, Der p 21 and Der p 23 was tested in patients' sera using the last version of the multiparametric assay Allergy Explorer (ALEX). Results. In all, major and minor allergens were positive, respectively, in 96.8% and 50.9% of the patients. Prevalence and IgE levels of Der f 1, Der f 2, Der p 1 and Der p 20 were significantly higher in asthmatic patients (p less than 0.05), whereas subjects negative for minor allergens resulted more frequently suffering from rhinitis (p = 0.0001). Asthmatic patients had IgE reactivity to a larger number of HDM allergens (mean 5.4; SD ± 2.3) than patients with only rhinitis (mean 4.2; SD ± 2.5) (p = 0.003), whereas no differences in the number of HDM positive molecules and in the specific IgE levels were found among different ages. Conclusions. This study confirms that the assessment of IgE to a comprehensive panel of HDM allergens defines different serological reactivity profiles that seem associated with different clinical presentations.

Molecular Allergy Diagnosis in Clinical Practice: Frequently Asked Questions

Considerable progress has been made in the field of molecular biology in recent years, enabling the study of sensitization to the individualcomponents of an allergenic source, a practice that has been termed molecular allergy diagnosis (MD) or component-resolved diagnosis (CRD).The present review provides the clinician with a practical approach to the use of MD by answering questions frequently asked by physicianson how MD can help improve the diagnosis of allergy in daily clinical practice.The article is divided into 3 sections. First, we provide a brief review of the importance for the clinician of knowing the main allergens inthe different allergenic sources, their structure, and their in vitro cross-reactivity before approaching MD (section A). Second, we reviewthe usefulness of MD in clinical practice (section B) and answer frequently asked questions on the subject. Finally, section C addresses theinterpretation of MD and its integration with other tools available for the diagnosis of allergy (AU)

En las últimas décadas ha habido un gran avance en el campo de la biología molecular permitiendo el estudio de la sensibilización acomponentes alergénicos individuales de una fuente alergénica. Dicha práctica se ha denominado Diagnóstico Molecular en alergia (DM)o Diagnóstico por Resolución de Componentes (CRD, según las iniciales en inglés).El propósito de la presente revisión es ofrecer al clínico un enfoque práctico para el uso del DM respondiendo preguntas frecuentes entrelos médicos sobre cómo puede ayudarnos a mejorar el diagnóstico de alergia en nuestra práctica clínica diaria.La revisión se divide en tres secciones. En primer lugar, se realiza una breve revisión sobre la importancia que tiene para el clínico conocerlos principales alérgenos de las diferentes fuentes alergénicas, su estructura y su reactividad cruzada in vitro antes de abordar el DM(apartado A). En segundo lugar, está el núcleo de la revisión sobre la utilidad del DM en la práctica clínica (apartado B) respondiendo alas preguntas frecuentes sobre el tema, y, finalmente, se añade un apartado (C) sobre la interpretación e integración del DM con el restode las herramientas disponibles para el diagnóstico de alergia (AU)

Development of a sensitive and stable chemiluminescent immunoassay for detection of birch pollen allergic specific IgE based on recombinant Bet v1 protein.

Background Quantitative detection of allergens is of great significance for clarifying the cause, treatment, and prevention of allergy disease. Birch pollen is one of the most common inhalational allergens and Bet v1 is the major component allergen of birch allergen. This study aims to develop a stable and sensitive chemiluminescence immunoassay (CLIA) for the detection of birch pollen allergic specific IgE (sIgE) based on recombinant Bet v1 (rBet v1) protein. Methods rBet v1 protein was expressed in Escherichia coli and purified. Then rBet v1 was applied to detect sIgE in human serum. The performance of the established CLIA was evaluated and compared with Phadia rBet v1 fluorescence enzyme immunoassay (FEIA) system. Results The developed CLIA for sIgE to rBet v1 detection shows excellent performance. The assay showed a linear range from 0.1 to 100 IU/mL, with a low detection limit of 0.06 IU/mL. A total of 164 samples were evaluated by CLIA and compared with the results of FEIA. The positive, negative, and total coincidence rate was 90.6% (87/96), 91.2% (62/68), and 90.9% (149/164), respectively. The r-value of Spearman's rank correlation analysis was 0.935 (P < 0.001). The use of high levels of bilirubin (50 mg/dL), hemoglobin (400 mg/dL) and lipid (2000 mg/dL) didn't interfere with the results. Conclusions The proposed CLIA exhibits excellent performance for the detection of rBet v1 specific IgE. It can be a reliable tool for the early diagnosis of hypersensitivity.

Cockroaches: Allergens, Component-Resolved Diagnosis (CRD) and Component-Resolved Immunotherapy.

Allergic diseases are assuming increasing trend of prevalence worldwide. The diseases confer increasing demand on medical and healthcare facilities. Patients with allergies have poor quality of life and impaired cognition. Adult patients have subpar working efficiency while afflicted children are less effective at school, often have school absenteeism and need more attention of their caregivers. All of them lead to negative socio-economic impact. This narrative review focuses on cockroach allergy including currently recognized cockroach allergens, pathogenic mechanisms of allergy, componentresolved diagnosis and allergen-specific immunotherapy, particularly the component-resolved immunotherapy and the molecular mechanisms that bring about resolution of the chronic airway inflammation.

Evaluation of serum IgE in peach-allergic patients with systemic reaction by using recombinant Pru p 7 (gibberellin-regulated protein).

BACKGROUND: Lipid transfer protein (LTP) is a major fruit allergen. It has, however, recently been revealed that the systemic reaction in peach-allergic patients is related not only to LTP (Pru p 3) but also to gibberellin-regulated protein (Pru p 7). We investigated recombinant Pru p 7 (rPru p 7) for its potential use in worldwide standardization for the diagnosis of peach allergy. METHODS: Natural Pru p 7 (nPru p 7) was purified from peach crude extract using a monoclonal antibody affinity column. Complementary DNA for Pru p 7 was cloned and expressed in Escherichia coli and Pichia pastoris. Serum immunoglobulin (Ig) E in peach-allergic patients was examined by enzyme-linked immunosorbent assay (ELISA) using nPru p 7 and rPru p 7 (E. coli product: erPru p 7 and P. pastoris product: prPru p 7). RESULTS: Peach-allergic patients (n=27) were diagnosed and categorized into oral reaction (n=10) or systemic reaction (n=17). The nPru p 7 positivity based on serum IgE levels was 52% in the systemic-reaction group and 0% in the oral-reaction group (P<0.05). In the systemic-reaction group, there was no significant difference in reactivity between nPru p 7 and prPru p 7, but the reactivity of erPru p 7 was significantly lower than those of nPru p 7 and prPru p 7 (P<0.05). CONCLUSIONS: We found that prPru p 7 exhibited reactivity in ELISA comparable to that of nPru p 7 for the diagnosis of peach allergy with systemic reaction.

Association Between Asthma and Sensitization to Allergens of Dermatophagoides pteronyssinus.

BACKGROUND AND OBJECTIVE: Little is known about the role of molecular diagnosis in house dust mite (HDM) allergy. In this study, we investigated the association between the sensitization profile of adolescent and adult HDM-allergic patients and asthma in a region with high rates of exposure to HDM. METHODS: We conducted a cross-sectional study of 384 HDM-allergic patients (38.5%, males; median age, 28 years). A total of 368 patients (95.8%) had rhinitis, and 175 (45.6%) had asthma. Specific IgE (sIgE) to Dermatophagoides pteronyssinus, nDer p 1, rDer p 2, and rPen a 1 was measured in all patients. sIgE to Lepidoglyphus destructor was measured in patients (n=301) with a positive skin test result. RESULTS: Significantly higher concentrations of sIgE to Der p 1 and sIgE to Der p 2 were observed in patients with asthma than in those without asthma. The proportion of asthmatic patients was higher among individuals who reacted (≥0.35 kUA/L) to both Der p 1 and Der p 2 (147/291, 50.5%) than among those who reacted to only 1 allergen (either Der p 1 or Der p 2, 18/55, 32.7%) or neither allergen (10/38, 26.3%, P=.002). Reactivity to both allergens was associated with asthma after adjusting for age and sex (OR, 2.87; 95%CI, 1.32-6.20). Higher concentrations of sIgE to L destructor were observed in patients with asthma than in patients without asthma. Tropomyosin sIgE ≥0.35 kUA/L was detected in only 6 individuals (1.6%). CONCLUSIONS: L destructor may be a relevant allergen in high-exposure areas. Dual sensitization (ie, IgE to both Der p 1 and Der p 2) may help to identify HDM-allergic patients who are at risk of asthma.

Utility of component analyses in subjects undergoing sublingual immunotherapy for peanut allergy.

BACKGROUND: Sublingual immunotherapy (SLIT) with peanut changes clinical and immune responses in most peanut-allergic individuals, but the response is highly variable. OBJECTIVE: We sought to examine the component-specific effects of peanut SLIT and determine whether peanut component testing could predict the outcome of a double-blind, placebo-controlled food challenge (DBPCFC) after 12 months of peanut SLIT. METHODS: We included 33 subjects who underwent peanut SLIT with a DBPCFC of 2500 mg of peanut protein performed after 12 months of therapy. Plasma samples from baseline and after 12 months of peanut SLIT were assayed using ImmunoCAP for IgE and IgG4 against whole peanut, Ara h 1, Ara h 2, Ara h 3, Ara h 8, and Ara h 9. RESULTS: Following 12 months of SLIT, 10 subjects (30%) passed the DBPCFC without symptoms and were considered desensitized. Subjects that failed the DBPCFC tolerated a median of 460 mg peanut protein (range: 10-1710 mg). The desensitized group had significantly lower baseline levels of IgE against peanut (median 40.8 vs. 231 kUA /L, P = 0.0082), Ara h 2 (median 17 vs. 113 kUA /L, P = 0.0082), and Ara h 3 (median 0.3 vs. 8.5 kUA /L, P = 0.0396). ROC curves indicated that baseline IgE against peanut and Ara h 2 were equally effective at discriminating between the two groups (AUC = 0.7957, P = 0.007752 for both). CONCLUSION AND CLINICAL RELEVANCE: In this cohort of subjects undergoing SLIT for peanut allergy, lower baseline levels of IgE against Ara h 2, Ara h 3, and peanut were associated with successful desensitization.