Profiles of Birch Sensitization (Bet v 1, Bet v 2, and Bet v 4) and Oral Allergy Syndrome Across Italy
Ciprandi G1, Comite P2, Mussap M2, De Amici M3, Quaglini S4, Barocci F5, Marseglia GL3, Scala E6
1Allergy Department, IRCCS-AOU San Martino-IST, Genoa, Italy
2Laboratory Medicine Department, IRCCS-AOU San Martino, Genoa, Italy
3Department of Pediatrics, Foundation IRCCS Policlinico San Matteo, Pavia, Italy
4Department of Electrical, Computer and Biomedical Engineering, University of Pavia, Pavia, Italy
5Immunohematology and Transfusion Medicine Unit, Rho, Italy, A.O. G. Salvini, Garbagnate Milanese, Italy
6Experimental Allergy Unit, IDI-IRCCS, Rome, Italy
J Investig Allergol Clin Immunol 2016; Vol 26(4)
Background: Birch allergy (BA) is a common pollinosis caused by the allergens Bet v 1, Bet v 2, and Bet v 4. Oral allergy syndrome (OAS) is frequently associated with BA. A gradient of sensitization to birch allergen across Europe has been reported. Therefore, this study aimed to investigate the birch sensitization profile, including OAS, across Italy.
Methods: We performed a retrospective study of 854 patients (391 males, mean age 35.9 years, range 18-93 years): 196 patients were recruited in Genoa, 188 in northern Italy, 359 in central Italy, and 111 in southern Italy. Serum IgE to Bet v 1, Bet v 2, and Bet v 4 was assessed, and OAS was analyzed.
Results: With respect to the geographical path Genoa-North-Center-South, the frequency of sensitization to Bet v 1 decreased significantly (P<.0001) from Genoa (95.41%) to southern Italy (58.56%). The frequency of sensitization to Bet v 2 increased significantly (P<.0001) from Genoa (6.12%) to southern Italy (52.25%). The frequency of Bet v 4 also increased significantly (P=.0002) from Genoa (6.12%) to southern Italy (14.41%). The distribution of patients with OAS differed significantly across the areas (P<.0001), the most marked difference ranging between 33.5% in Genoa and 76.9% in northern Italy. The frequency of birch allergens correlated with OAS in central Italy only.
Conclusions: The present study demonstrated a significant difference between sensitization to birch and its clinical expression across Italy.
Key words: Bet v 1, Bet v 2, Bet v 4, Oral allergy syndrome, Birch allergy, Serum IgE, Italy.