Relevance of Allergenic Sensitization to Cynodon dactylon and Phragmites communis: Cross-reactivity With Pooideae Grasses
López-Matas MA1, Moya R1, Cardona V2, Valero A3, Gaig P4, Malet A5, Viñas M6, García-Moral A3, Labrador M2, Alcoceba E7, Ibero M6, Carnés J1
1R&D Department, Laboratorios LETI S.L.U., Tres Cantos, Madrid, Spain
2Allergy Unit, Hospital General de la Vall d’Hebron, Barcelona, Spain
3Allergy Unit, Hospital Clínic de Barcelona, Barcelona, Spain
4Allergy Unit, Hospital Universitari Joan XXIII, Tarragona, Spain
5Allergo Centre, S.L.P., Barcelona, Spain
6Allergy Unit, Hospital de Terrassa, Barcelona, Spain
7Allergy Unit, Hospital Arnau de Vilanova, Lleida, Spain
J Investig Allergol Clin Immunol 2016; Vol 26(5)
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.
Key words: Grass allergy, Cross-reactivity, Cynodon dactylon, Phragmites communis, Phl p 1, Cyn d 1.