D2.398 - Is Cynodon dactylon an important cause of pollinosis in Madrid?

Grass pollen is the main cause of pollinosis in Madrid. Both grass subfamilies, Pooideae (Trisetum paniceum, Dactylis glomerata, etc.) and Chloridoideae (Cynodon dactylon), are abundant plants in the surrounding areas of the city. However, exist a problem for the prescription of accurate immunotherapy, due to the low, but present partial cross-reactivity between Phl p 1 and Cyn d 1.

Pollen counts were done with a Burkard seven days volumetric spore trap (Burkard Manufacturing, Rickmansworth, Herst., U.K.) from 1979 to 2024 (45 years).

Additionally, we performed Alex Allergy Explorer (Macro Array Diagnostics GmbH, Austria) in 1,584 patients with pollinosis born and residing in Madrid and studied consecutively during 2022-23.

The highest airborne presence was for Platanus sp. (22%) followed by Quercus spp. (18%), Cupressaceae (13%), Poaceae (10%), Olea sp. (6%), Pinus spp. (5%), and Populus spp. (3%)

The most significant allergenic pollen was for grasses, with a prevalence of positive (Phl p 1 and/or Phl p 5) of 68%, followed by Cupressus arizonica (Cup a 1) of 61%, Olea europea (Ole e 1) of 58%, Platanus acerifolia (Pla a 1 and/or Pla a 2) of 28%. Less prevalence was for Plantago lanceolata (Pla l 1) of 8% Salsola kali (Sal k 1) 10%, Chenopodium album (Chen a 1) 2 %, Artemisia vulgaris (Art v 1) of 4%, Parietaria (Par j 2) of 5%. Profilins was 42%, Polcalcines 16%, LTPS 18%, storage proteins 15%, PR-10 14%.

Although the prevalence of Cyn d 1 was 45%, in contrast, it was only 2.3% in those genuinely sensitized to Cynodon but not to Pooideae (Cyn d 1 > Phl p 1 and Phl p 5 neg.).

1. Cynodon dactylon is not a frequent cause of grass genuine sensitization in Madrid.
2. On the contrary, the subfamily Pooideae represents by far the most frequent cause of genuine sensitization to grasses.