Is Lolium pollen from an urban environment more allergenic than rural pollen?

Allergy to grass pollen is a highly prevalent allergic disease. Hay fever is more predominant in urban than in rural areas, despite the increasingly smaller areas of surrounding grassland. The effect of vehicle exhaust pollutants, mainly diesel particles, and other industrial sources of atmospheric pollution leading to plant damage has been implicated in this phenomenon This study compared the in vivo and in vitro allergenicity of pooled samples of Lolium perenne grass pollen harvested from 10 different urban areas with that of samples of the same pollen from 10 neighboring rural areas Lolium perenne pollen from different parts of a city and from a nearby rural area was harvested in 1999 and 2000 during the peak pollination period. Protein composition was compared by SDS-PAGE and in vivo and in vitro IgE-binding capacity was compared by skin-prick tests, RAST-inhibition and measurement of the major allergen, Lol p 5 In the two years under study, urban samples contained approximately twice the protein content of the rural samples. Biological activity and Lol p 5 content was higher in urban pollen than in rural pollen and showed differences in the two years under study The protein content and allergenicity of Lolium perenne pollen was higher in urban areas than in rural areas. These differences might explain why allergy to grass pollen is more prevalent in urban areas. This finding should be taken into account in diagnosis, preventive measures and specific immunotherapy Los pólenes son una causa muy importante de enfermedades alérgicas. La polinosis es mas prevalente en zonas urbanas que en rurales, a pesar de que cada vez hay menos zonas verdes en las ciudades. Se ha valorado el efecto de las partículas diesel y otras fuentes de contaminantes urbanos sobre los pólenes para tratar de explicar este fenómeno Este estudio compara la alergenicidad de muestras de Lolium perenne recolectado en diferentes zonas de la ciudad de Valladolid con pólenes de la misma especie recogidos en zonas rurales vecinas Se recolectaron pólenes de Lolium perenne de diferentes partes de la ciudad y de zonas rurales circundantes durante su pico de polinización en los años 1999 y 2000. Se mide su reactividad “in vivo” mediante prick tests e “in vitro” por SDS-PAGE, RAST inhibición y medición de su alergeno principal Lol p 5, y se comparan los resultados obtenidos por todas la técnicas Demostramos una mayor concentración proteica y alergenicidad de los pólenes de Lolium perenne de zonas urbanas comparadas con las rurales cercanas Sugerimos que esta diferencia en concentración proteica y actividad biológica del polen según el lugar de procedencia debería ser tenida en cuenta para el diagnóstico, medidas de prevención e inmunoterapia específica