BACKGROUND: Walnut is the most common cause of allergic reactions to tree nuts, as reported by large population studies. Two major allergens of walnut have been identified up until now: a 2S albumin and a vicilin-like protein. OBJECTIVE: This study was designed to identify the walnut major allergens in the Italian population and to compare the walnut IgE-binding profile in patients with or without pollen allergy. METHODS: We selected 46 patients either with oral allergy syndrome confirmed by open oral challenge or with systemic symptoms after ingestion of walnut. These patients' sera were used for the immunoblotting of walnut extract; the identified allergens were purified by HPLC and sequenced. A peach-walnut cross-inhibition study was then performed. RESULTS: The only major allergen recognized by our study population was a 9-kd lipid transfer protein (LTP), recognized by 37 patients. Two other minor allergens of approximately 9-kd molecular weight, both belonging to the vicilin family, were recognized by 10 patients. IgE binding to walnut LTP was completely inhibited by peach LTP. CONCLUSION: In Italian patients with walnut allergy confirmed by documented history of severe systemic reactions or by open oral food challenge, the major allergen is an LTP. The sensitization to this protein seems to be secondary to the sensitization to peach LTP, which acts as the primary sensitizer. LTP and vicilins were able to sensitize patients not allergic to pollen.
BACKGROUND: Walnut is the most common cause of allergic reactions to tree nuts, as reported by large population studies. Two major allergens of walnut have been identified up until now: a 2S albumin and a vicilin-like protein. OBJECTIVE: This study was designed to identify the walnut major allergens in the Italian population and to compare the walnut IgE-binding profile in patients with or without pollen allergy. METHODS: We selected 46 patients either with oral allergy syndrome confirmed by open oral challenge or with systemic symptoms after ingestion of walnut. These patients' sera were used for the immunoblotting of walnut extract; the identified allergens were purified by HPLC and sequenced. A peach-walnut cross-inhibition study was then performed. RESULTS: The only major allergen recognized by our study population was a 9-kd lipid transfer protein (LTP), recognized by 37 patients. Two other minor allergens of approximately 9-kd molecular weight, both belonging to the vicilin family, were recognized by 10 patients. IgE binding to walnut LTP was completely inhibited by peach LTP. CONCLUSION: In Italian patients with walnut allergy confirmed by documented history of severe systemic reactions or by open oral food challenge, the major allergen is an LTP. The sensitization to this protein seems to be secondary to the sensitization to peach LTP, which acts as the primary sensitizer. LTP and vicilins were able to sensitize patients not allergic to pollen.
Authors: Alexander C Y Foo; Jacqueline B Nesbit; Stephen A Y Gipson; Hsiaopo Cheng; Pierre Bushel; Eugene F DeRose; Catherine H Schein; Suzanne S Teuber; Barry K Hurlburt; Soheila J Maleki; Geoffrey A Mueller Journal: J Agric Food Chem Date: 2022-02-09 Impact factor: 5.279
Authors: Isabel J Skypala; Ricardo Asero; Domingo Barber; Lorenzo Cecchi; Arazeli Diaz Perales; Karin Hoffmann-Sommergruber; Elide A Pastorello; Ines Swoboda; Joan Bartra; Didier G Ebo; Margaretha A Faber; Montserrat Fernández-Rivas; Francesca Gomez; Anastasios P Konstantinopoulos; Olga Luengo; Ronald van Ree; Enrico Scala; Stephen J Till Journal: Clin Transl Allergy Date: 2021-05-18 Impact factor: 5.871
Authors: Arantxa Palacín; Cristina Gómez-Casado; Luis A Rivas; Jacobo Aguirre; Leticia Tordesillas; Joan Bartra; Carlos Blanco; Teresa Carrillo; Javier Cuesta-Herranz; Consolación de Frutos; Genoveva García Alvarez-Eire; Francisco J Fernández; Pedro Gamboa; Rosa Muñoz; Rosa Sánchez-Monge; Sofía Sirvent; María J Torres; Susana Varela-Losada; Rosalía Rodríguez; Victor Parro; Miguel Blanca; Gabriel Salcedo; Araceli Díaz-Perales Journal: PLoS One Date: 2012-12-14 Impact factor: 3.240
Authors: Luis Diego Archila; David Jeong; Mariona Pascal; Joan Bartra; Manel Juan; David Robinson; Mary L Farrington; William W Kwok Journal: J Allergy Clin Immunol Date: 2015-03-13 Impact factor: 10.793