R-mandelonitrile-lyase, homolog to Pru d 10, is a major peach allergen in peach allergic Spanish population.

BACKGROUND AND OBJECTIVE: Peach allergy is a prevalent cause of food allergy. Despite the repertoire of allergens available for molecular diagnosis, there are still patients with undetectable IgE levels to peach allergens but presenting symptoms after its ingestion. The objective of this study was to investigate the allergenic profile in a patient population with symptoms produced by peach. METHODS: An exploratory retrospective study was performed with patients presenting symptoms after the ingestion of peach. Forty-two patients were included in the study. The allergenic profile of individual patients was investigated by immunoblot. A serum pool was prepared with the sera that recognized a 70 kDa band. This pool was used to detect this protein in peach peel and pulp and to identify the 70 kDa protein in 2D immunoblot. Spots recognized in the 2D immunoblot were sequenced by LC-MS/MS. Inhibition studies were performed between peach peel and almond. RESULTS: Twenty-two patients (52.4%) recognized the 70 kDa protein in immunoblot. This protein was recognized in peel and pulp. Two different spots were observed in 2D-PAGE, both were identified as (R)-mandelonitrile lyases (RML) with high amino acid similarity with Pru du 10. Peach RML were partially inhibited with an almond extract. No association was found between any reported symptom and sensitization to RML. RML-sensitized patients were older and reported pollen associated respiratory symptoms more frequently than negative patients. CONCLUSION: A new peach allergen, a RML, homologous of Pru du 10, recognized by 52% of the population has been identified.

Sensitization to Vitis vinifera Pollen in a Wine Production Area: Identification of the Allergens Involved.

BACKGROUND: Vine cultivation is widely distributed in La Rioja, Spain (37% of all crops) and is associated with exposure of the general population to vine pollen. The aims of this study were to investigate the prevalence of sensitization to Vitis vinifera pollen in persons with respiratory allergy in the general population and to identify the allergens involved. MATERIALS AND METHODS: The study population comprised patients who came to the hospital between September 2019 and January 2020 with suspected respiratory allergy. All patients underwent skin prick testing with a panel of standardized aeroallergens, profilin, lipid transfer protein (LTP), and V vinifera pollen extract and prick-prick testing with fresh grapes. The in vitro study included specific IgE by ImmunoCap and ELISA, allergenic profile by immunoblot with individual sera from patients positive to V vinifera pollen extract, and 2D immunoblot with a pool of sera. The spots recognized by IgE were identified using mass spectrometry. RESULTS: A total of 151 patients were included. Of these, 124 were positive to some of the allergens tested. Thirty-four (27.4%) were positive to vine pollen in the skin prick tests. The serology study revealed positive results in 20 patients. Five vine pollen allergens were identified, and profilin was the most prevalent (30%). The other 4 allergens could be considered specific to this pollen. CONCLUSIONS: Sensitization to vine pollen was frequent in the general population in a vine growing area. The clinical relevance of this finding is unknown owing to sensitization to other pollens in the vine pollen-positive patients. Five new vine pollen allergens were identified.

Sensitization to Vitis vinifera Pollen in a Wine Production Area: Identification of the Allergens Involved

Background: Vine cultivation is widely distributed in La Rioja, Spain (37% of all crops) and is associated with exposure of the general population to vine pollen. The aims of this study were to investigate the prevalence of sensitization to Vitis vinifera pollen in persons with respiratory allergy in the general population and to identify the allergens involved. Materials and Methods: The study population comprised patients who came to the hospital between September 2019 and January 2020 with suspected respiratory allergy. All patients underwent skin prick testing with a panel of standardized aeroallergens, profilin, lipid transfer protein (LTP), and V vinifera pollen extract and prick-prick testing with fresh grapes. The in vitro study included specific IgE by ImmunoCap and ELISA, allergenic profile by immunoblot with individual sera from patients positive to V vinifera pollen extract, and 2D immunoblot with a pool of sera. The spots recognized by IgE were identified using mass spectrometry. Results: A total of 151 patients were included. Of these, 124 were positive to some of the allergens tested. Thirty-four (27.4%) were positive to vine pollen in the skin prick tests. The serology study revealed positive results in 20 patients. Five vine pollen allergens were identified, and profilin was the most prevalent (30%). The other 4 allergens could be considered specific to this pollen. Conclusions: Sensitization to vine pollen was frequent in the general population in a vine growing area. The clinical relevance of this finding is unknown owing to sensitization to other pollens in the vine pollen–positive patients. Five new vine pollen allergens were identified (AU)

Antecedentes: El cultivo de la vid está ampliamente distribuido en La Rioja (37% de los cultivos), lo que supone una exposición de la población general al polen de esta planta. El objetivo de este estudio fue investigar la prevalencia de sensibilización al polen de Vitis vinifera en la población general con alergia respiratoria e identificar los alérgenos implicados. Materiales y métodos: Se incluyeron en el estudio pacientes que acudieron al hospital entre septiembre de 2019 y enero de 2020 con sospecha de alergia respiratoria. A todos ellos se les realizó una prueba cutánea con el panel de aeroalérgenos estandarizados, profilina, LTP, extracto de polen de V. vinifera y Prick prick con uva. El estudio in vitro incluyó IgE específica mediante ImmunoCap y ELISA, perfil alergénico por inmunoblot con sueros individuales de pacientes positivos al extracto de polen de V. vinifera e inmunoblot 2D con un pool de sueros. Las proteínas reconocidas por la IgE fueron identificadas por espectrometría de masas. Resultados: Se incluyeron un total de 151 pacientes. De ellos, 124 fueron positivos a algunos de los alérgenos analizados. 34 (27,4%) fueron positivos a polen de vid por prueba cutánea. 20 fueron positivos tras el estudio serológico. Se identificaron 5 alérgenos del polen de la vid, siendo la profilina el más prevalente (30%). Los otros 4 alérgenos podrían considerarse específicos de este polen. Conclusión: Se detectó una alta sensibilización al polen de vid en la población general en una zona de viñedos. Se desconoce la relevancia clínica debido a la sensibilización a otros pólenes en los pacientes positivos a polen de vid. Se identificaron 5 nuevos alérgenos del polen de la vid (AU)

Immunoinformatic epitope prediction to select monoclonal antibodies for Phl p 1 quantification.

BACKGROUND: Allergen quantification has become a relevant parameter for allergen extract characterization and to guarantee the consistency of the manufacturing process at allergen immunotherapy. The aim of this study was to develop and validate a method to quantify the major allergen Phl p 1 based on a prediction of the antigenic regions by immunoinformatic strategies. METHODS: Phl p 1 was purified from a Phleum pratense native extract by chromatographic methods. Immunoinformatic tools were used to predict B-cell epitopes. In silico predictions were verified by mapping linear epitopes with a peptide library and used to select the appropriate regions for producing the mAbs to develop an ELISA method, which was validated. Phl p 1 was quantified in 24 batches of P. pratense extracts. RESULTS: Phl p 1 was purified with 95 % purity and completely functional. Eight B-cell epitopes in each of the two Phl p 1 isoforms were predicted. Two of the predicted B-cell epitopes overlapped with the experimentally determined peptides recognized by two mAbs selected for development of the kit. The quantification method demonstrated to be specific to Phl p 1, linear, accurate and precise in the range from 7.7 to 123.3 µg/mg. Mean Phl p 1 content was 28.95 µg of allergen/mg of lyophilized native extract and 44.23 µg of allergen/mg of lyophilized depigmented extract. CONCLUSIONS: An ELISA method for measuring Phl p 1 in P. pratense extracts was developed and validated by producing the appropriate mAbs against epitopes selected by immunoinformatic tools.

Profilin is a marker of severity in allergic respiratory diseases.

BACKGROUND: The capacity of profilin to induce allergic symptoms in patients with respiratory allergy has been questioned. In this sense, the aim of this study was to investigate the correlation between profilin exposure and induction of symptoms in a prospective case-control study. METHODS: The concentration of profilin as well as pollen levels in the air was measured. A diary score of symptoms was collected from allergic patients. Seventy-nine individuals were included in the study; fifty cases and 28 controls were positive or negative to profilin, respectively. Conjunctival and bronchial provocation tests were performed with purified profilin (Pho d 2) in a subgroup of cases and controls. RESULTS: Profilin was detected in the environment on 133 days (maximum peak of 0.56 ng/m3 ). A positive correlation between profilin and pollen count of Olea and Poaceae was observed (ρ = 0.24; P < .001). Intensity of total, nasal and ocular symptoms was statistically higher in cases than in controls (P < .001). The risk of suffering symptoms, measured by the percentage of patients who presented any of the symptoms each day, was also higher in cases than in controls. The provocation test was positive in 95% of bronchial and 90% of conjunctival challenges in cases, and negative in all controls. CONCLUSIONS: Profilin was detected in the environment and had the ability to induce a specific allergen response. Patients sensitized to this panallergen showed more symptoms and were more likely to have symptoms. Therefore, sensitization to profilin seems to be a marker of severity in patients with rhinoconjunctivitis and asthma mediated by pollen.

Opinión de médicos urgenciólogos sobre la práctica de ecografías por médicos no radiólogos / Opinion of emergency phisicians on the utilization of ultrasound by non-radiologist physicians

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Purification and immunochemical characterization of Pla l 2, the profilin from Plantago lanceolata.

Profilins are small actin-binding proteins found in eukaryotes and involved in cell development, cytokinesis, membrane trafficking, and cell motility. From an allergenic point of view, profilins are panallergens usually involved in allergic polysensitization, although they are generally recognized as minor allergens. The objectives of this study were to identify and characterize the profilin from Plantago lanceolata pollen and to investigate the cross-reactivity between profilins from different pollen allergenic sources. Profilins from P. lancelolata (Pla l 2) and palm tree pollen (Pho d 2) were purified by affinity chromatography, deeply characterized and identified by mass spectrometry. Pla l 2 allergenicity was confirmed by immunoblot with serum samples from a patient population sensitized to profilin. Immunoblot inhibition was performed to study IgG reactivity between different pollen profilins. IgE cross-reactivity was demonstrated by ImmunoCAP inhibition. Pla l 2 is the second P. lanceolata allergen included in the IUIS Allergen Nomenclature database. Four peptides from purified Pla l 2 were identified with percentages of homology with other pollen profilins between 73 and 86%. Eighty-six percent (21/24) of the patient population recognized Pla l 2. The allergenic relatedness between Pla l 2, Pho d 2 and six pollen profilins was confirmed, and IgE cross-reactivity of Pla l 2 with rBet v 2 and rPhl p 12 was demonstrated. Pla l 2 is the profilin from P. lanceolata. The demonstrated allergenicity of this protein and its cross-reactivity with other pollen profilins support its use in profilin diagnostic assays.

Relevance of Allergenic Sensitization to Cynodon dactylon and Phragmites communis: Cross-reactivity With Pooideae Grasses.

BACKGROUND AND OBJECTIVES: The homologous group of sweet grasses belongs to the Pooideae subfamily, but grass pollen species from other subfamilies can also cause allergy, such as Cynodon dactylon (Chloridoideae) and Phragmites communis (Arundinoideae). C dactylon and P communis have not been included in the sweet grasses homologous group because of their low cross-reactivity with other grasses. The aims of this study were to investigate the profile of sensitization to C dactylon and P communis in patients sensitized to grasses and to analyze cross-reactivity between these 2 species and temperate grasses. METHODS: Patients were skin prick tested with a grass mixture (GM). Specific IgE to GM, C dactylon, P communis, Cyn d 1, and Phl p 1 was measured by ImmunoCAP. A pool of sera was used for the immunoblot assays. Cross-reactivity was studied by ELISA and immunoblot inhibition. RESULTS: Thirty patients had sIgE to GM. Twenty-four (80%) had positive results for C dactylon, 27 (90%) for P communis, 22 (73.3%) for nCyn d 1, and 92.9% for rPhl p 1. Bands were detected in the 3 extracts by immunoblot. Inhibition of GM was not observed with C dactylon or P communis by immunoblot or ELISA inhibition. When C dactylon or P communis were used in the solid phase, GM produced almost complete inhibition. CONCLUSIONS: Eighty percent of patients sensitized to grasses were also sensitized to C dactylon and 90% were sensitized to P communis. Sensitization to these species seems to be induced by allergens different to those in sweet grasses.

In vivo diagnosis with purified tropomyosin in mite and shellfish allergic patients.

BACKGROUND: Tropomyosin is the most studied shellfish allergen and has been involved in cross-reactivity among different invertebrates (crustacean, mollusks, mites, insects, and nematodes). OBJECTIVE: To determine the relevance of tropomyosin in mite- and shellfish-sensitized patients using tropomyosin skin testing. METHODS: Patients were divided into 3 groups: group M included mite allergic patients (ie, individuals with respiratory symptoms and a positive result on skin prick testing [SPT] to house dust mites), group S included shellfish allergic patients (ie, individuals who reported symptoms with shellfish), and group MS included mite- and shellfish allergic patients (ie, individuals who simultaneously fulfilled the inclusion criteria for groups M and S). Tropomyosin was purified from shrimp, characterized, and used in SPT for diagnosis in the patient population. RESULTS: Eight hundred fifty patients were included in the study: 790 (92.9%) in group M, 21 (2.5%) in group S, and 39 (4.6%) in group MS. Tropomyosin was purified from shrimp with a purity higher than 95%. Forty-two individuals tested positive to tropomyosin: the prevalence was 2.7% in group M, 28.6% in group S, and 38.5% in patients of group MS. Twenty-one (50%) of the tropomyosin-positive individuals had symptoms with shellfish, and 3 (14.3%) reported anaphylaxis. CONCLUSION: The prevalence of tropomyosin was low in mite-sensitized patients (2.7 %) and high in shellfish allergic patients (28.6%). The higher prevalence of tropomyosin was found in patients sensitized to both mite and shellfish (38.5%). The selection of tropomyosin-sensitized patients by SPT might help in the choice of appropriate treatments or management for these patients.

Cloning and characterization of tropomyosin from the mite Chortoglyphus arcuatus.

Tropomyosin is a pan-allergen that shares a high homology among species. It is involved in cross-reactivity among mites, crustaceans, mollusks and insects. The objectives were to express and purify recombinant tropomyosin from the storage mite Chortoglyphus arcuatus, and to investigate the homology and cross-reactivity with tropomyosin from other invertebrates. Recombinant C. arcuatus tropomyosin (r-Cho a 10) was selected from a library by screening with a pool of patient sera. r-Cho a 10 (UniProt: H2DFL1) was sequenced, expressed in Escherichia coli and purified by ion exchange and affinity chromatography. Polyclonal anti-tropomyosin antibodies were produced in mice. IgE recognition of r-Cho a 10 was checked by immunoblot. Immunoblot inhibition assays were used to identify the native tropomyosin in the complete extract from C. arcuatus and study cross-reactivity between r-Cho a 10 and Der p 10. Identification of tropomyosin in other allergenic sources was performed by immunoblot. r-Cho a 10 showed a high homology (54-96%) with other tropomyosins from different allergenic sources. IgE recognition was observed using a pool of sera from sensitized individuals. Tropomyosins from different extracts were identified not only in the whole C. arcuatus extract but also in Dermatophagoides pteronyssinus, shrimp, mussel, cockroach and Anisakis extracts with polyclonal α-Cho a 10. r-Cho a 10 completely inhibited the recognition of Der p 10. Recombinant C. arcuatus tropomyosin maintained its capacity to recognize IgE. r-Cho a 10 was used to prove cross-reactivity among tropomyosins from other invertebrate species, including mites. This is the first C. arcuatus allergen included in the WHO/IUIS (World Health Organization/International Union of Immunological Societies) Allergen Nomenclature database.

Tomato nsLTP as an "In Vivo" Diagnostic Tool: Sensitization in a Mediterranean Population.

BACKGROUND: Tomato allergies have been extensively studied but component-resolved in vivo diagnosis with purified allergens has yet to be performed. OBJECTIVES: To evaluate the prevalence of sensitization to Sola l 3 in a Mediterranean population, and to compare the resulting sensitization profile with that of individuals sensitized to tomato, peach, and/or purified lipid transfer protein (LTP). METHODS: Sola l 3 was purified, characterized, and used to prepare skin prick tests (SPTs). Two groups of patients were selected. Group 1 consisted of patients with at least 1 positive SPT to tomato, peach, or LTP mixture (marker extracts) who were subsequently tested with Sola l 3 (n = 280). Group 2 (prevalence study) consisted of patients who underwent simultaneous SPT with the 3 marker extracts and Sola l 3 (n = 658). Patients from either group who were positive to any of the 4 extracts were studied in detail (study group, n = 1 23). ELISA and immunoblot assays were performed in individuals with a positive SPT to Sola l 3 to detect the presence of specific IgE antibodies to this allergen. RESULTS: Prevalence of sensitization to Sola l 3 was 3.2% overall and 54.7% in tomato-positive patients. Most tomato-sensitized patients were asymptomatic. Symptoms were more common in Sola l 3-positive individuals. Sensitization to peach and the LTP mixture did not discriminate between Sola l 3-positive and Sola l 3-negative patients. CONCLUSIONS: This study confirms that LTP, not only from peach but also from other fruit and vegetables, including tomato, is an important allergen in the Mediterranean area. Sensitization to Sola l 3 is associated with more symptoms in tomato-sensitized patients.

Allergenic profile to Phleum pratense and immunological changes induced after grass allergen-specific immunotherapy.

BACKGROUND: The introduction of molecular diagnoses has provided evidence of the existence of several different allergenic profiles in grass-sensitised individuals, reflecting the large number of allergens involved. This methodology has become a potent tool for a correct diagnosis and for the selection of the most appropriate immunotherapy. Based on these concepts, the objectives of this study were to determine the sensitisation profile of a grass-allergic population, and to treat them with specific immunotherapy. METHODS: Patients suffering from rhinitis and/or asthma associated with grass pollen were recruited. The active group was treated with depigmented-polymerised allergenic extract of mixed grass pollen. sIgE and sIgG4 to Phleum pratense, and to its individual components (Phl p 1, 2, 4, 5b, 6, 7, 11 and 12) were determined at the beginning and end of the study. RESULTS: The inclusion criteria were fulfilled by 139 individuals (36 in the control group and 103 in the active group). Phl p 1 (96.4%) and Phl p 4 (91.2%) were the most recognised allergens, and 15.3% of individuals had positive IgE to cross-reactive carbohydrate determinants. Levels of antigen-specific IgG4 increased significantly after treatment, and the IgE/IgG4 ratio decreased significantly in all allergens after receiving allergen-specific immunotherapy. Non-significant differences were observed in the control group. CONCLUSIONS: A high percentage of sensitisation to Phl p 4 was observed. Immunological efficacy was studied by measuring sIgG4 levels and the IgE/IgG4 ratio before and after treatment. Sensitisation profiles should be taken into consideration to prepare the most appropriate immunotherapy containing all the relevant and needed allergens.