IgE-mediated sensitization to galactose-alpha-1,3-galactose (a-gal) in urticaria and anaphylaxis in Spain: geographical variations and risk factors
Mateo-Borrega MB1, Garcia B2, Hernando Larramendi C3, Azofra J4, González-Mancebo E5, Alvarado MI6, Alonso Díaz de Durana MD7, Núñez-Orjales R8, Diéguez MC9, Guilarte M10, Soriano-Galarraga AM11, Sosa G12, Ferrer A13, García-Moral A14, Beristain AM15, Bartra J16
1GAI Guadalajara, Department of Allergy, Hospital Universitario de Guadalajara, Guadalajara, Spain.
2Department of Allergy, Complejo Hospitalario de Navarra, Pamplona, Spain.
3Allergy Section, Hospital Marina Baixa, Villajoyosa, Spain.
4Department of Allergy, Hospital Universitario Central de Asturias, Oviedo, Spain.
5Department of Allergy, Hospital Universitario de Fuenlabrada, Madrid, Spain.
6Department of Allergy, Hospital Virgen del Puerto, Plasencia, Spain.
7Department of Allergy, Hospital Universitario Fundación de Alcorcón, Madrid, Spain.
8Department of Allergy, Hospital Universitario Lucus Augusti, Lugo, Spain.
9Department of Allergy, Research Institute Hospital 12 de Octubre (i+12), Madrid, Spain.
10Department of Allergy, Hospital Universitari de la Vall d´Hebron, Barcelona, Spain.
11Department of Allergy, Hospital de Basurto, Bilbao, Spain.
12Allergy, Hospital La Zarzuela, Madrid, Spain.
13Department of Allergy, Hospital Vega Baja, Orihuela, Spain.
14Department of Allergy, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.
15Department of Allergy, Hospital Universitario Central de Asturias, Oviedo, Spain.
16Allergy Unit, Pneumology Department, Hospital Clinic, Barcelona, Spain
J Investig Allergol Clin Immunol 2019; Vol. 29(6)
Background: The aims of this study were to investigate the prevalence of sIgE to galactose-alpha-1,3-galactose (α-gal) in individuals with acute urticaria or anaphylaxis from different geographical areas of Spain and to evaluate the relevance of demographics and lifestyle as risk factors for this immune response.
Methods: Participants were recruited from allergy departments at 14 Spanish hospitals. Patients aged 18 years or older presenting with urticaria or anaphylaxis were enrolled into one of two arms: cases and controls. An interviewer-administered questionnaire collecting demographic data, lifestyle habits, and the presence of cofactors was obtained from each participant. sIgE to α-gal and total IgE were determined using ImmunoCAP®. sIgE levels ≥0.35 kU/l were considered a positive result.
Results: The study population comprised 160 cases and 126 controls. The median age was 44 years. The overall prevalence of a positive result of sIgE to α-gal was 15.7%; this was higher in cases (26.3%) than in controls (2.4%). The sIgE anti α-gal positivity rate ranged from 37.68% (rural) to 15.38% (semi-urban) and 7.85% (urban). The rates of positivity were 46.32%, (Northern), 0.72% (Center), and 0% (Mediterranean). A positive result of sIgE to α-gal associated with history of tick bites, participation in outdoor activities, pet ownership, and ingestion of mammalian meats or innards before the onset of symptoms. Only alcohol consumption could be implicated as a cofactor.
Conclusion: Sensitization to α-gal in patients with urticaria or anaphylaxis differs considerably between the three geographical areas studied and is related to tick bites.
Key words: Alpha-Gal, Risk Factors, Epidemiology, Outdoor Activities, Tick Bites, Cofactors.