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 (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)