Clinical impact and immunological alterations in asthmatic patients allergic to grass pollen subjected to high urban pollution in Madrid

• Published in: Clinical and experimental allergy 2022-04, Vol.52 (4), p.530-539
• Main Authors: Feo‐Brito, Francisco, Alfaya Arias, Teresa, Amo‐Salas, Mariano, Somoza Álvarez, María Luisa, Haroun Díaz, Elisa, Mayorga Mayorga, Cristobalina, Fernández Santamaría, Rubén, Urra Ardanaz, José Miguel
• Format: Article
• Language: English
• Subjects: Asthma; CD8 antigen; Cell proliferation; grass pollen; Nitrogen dioxide; NK cells; Patients; Pollen; Pollutants; Pollution; seasonal allergic asthma; T‐CD8
• ISSN: 0954-7894; 1365-2222
• DOI: 10.1111/cea.14041

Background The prevalence of asthma has increased in recent decades. Among the reasons for this increase is environmental pollution. Pollutants cause bronchial inflammation and introduce modifications in the pollen, making it more allergenic. Objective Assess symptoms and medication requirements of asthmatic patients with grass allergies in Madrid (high urban pollution) and Ciudad Real (low pollution), and simultaneously evaluate the in vitro effects that pollen collected in both areas has on the immune cells of patients. Methods During two pollen seasons, patients from both cities were included. The patients recorded their symptoms and the asthma medication they took daily. In both cities, pollen data, pollutants and meteorological variables were evaluated. The response to different cell populations from patients in both areas were analysed after “in vitro” stimulation with pollen from both cities. Results The symptoms and medication use of the patients in Madrid was 29.94% higher. The NO2 concentration in Madrid was triple that of Ciudad Real (33.4 vs. 9.1 µg/m3 of air). All other pollutants had very similar concentrations during the study period. Pollen from the high pollution area caused a significant enhancement of T‐CD8+ and NK cells proliferation compared with pollen of low pollution area, independently of the patient's origin. Conclusion Asthmatic patients from Madrid have a worse clinical evolution than those from Ciudad Real because of higher levels of urban pollution, and this could be driven by the higher capacity of pollen of Madrid to activate T‐CD8+ and NK cells. Patients with asthma caused by grass pollen are affected by high pollution rates. In areas with high pollution their clinical symptoms intensify, and patients require more medication. Pollen from highly polluted areas alters the immune system of patients. It causes in vitro an enhanced stimulation of T‐CD8+ and NK cells which could be responsible for the clinical worsening of the patients.