Photo Credit: Nikola Stojadinovic

The following is a summary of “Phl p 5 levels more strongly associated than grass pollen counts with allergic respiratory health,” published in the March 2024 issue of Allergy & Immunology by Fuertes, et al.

While several studies have established a connection between daily pollen counts and respiratory allergic health issues, fewer have explored the role of allergen levels. For a study, researchers sought to evaluate the relationships between grass pollen counts and grass allergen levels (specifically Phl p 5) with respiratory allergic symptoms in a cohort of 93 adults suffering from moderate to severe allergic rhinitis, alongside daily asthma hospital admissions in London, United Kingdom.

They collected daily symptom and medication scores from adult participants in an allergy clinical trial. Additionally, they obtained daily counts of hospital admissions for asthma from Hospital Episode Statistics data for the general population in London. Grass pollen counts were measured using a volumetric air sampler, while Phl p 5 levels were determined using ChemVol High Volume Cascade Impactor and ELISA analyses (conducted from May through August). Using logistic models with generalized estimating equations, they assessed associations between the two pollen variables and daily health scores (categorized based on within-person 75th percentiles). They also examined associations with asthma hospital admissions using Poisson regression models.

Both daily pollen counts and Phl p 5 levels were individually linked to reporting high combined symptom and medication health scores in separate models. However, in mutually adjusted models incorporating terms for both pollen counts and Phl p 5 levels, associations persisted for Phl p 5 levels (odds ratio [95% CI]: 1.18 [1.12, 1.24]), while they were substantially weakened for pollen counts (odds ratio [95% CI]: 1.00 [0.93, 1.07]). Comparable trends were not observed for asthma hospital admissions in London.

Grass allergen levels, specifically Phl p 5, demonstrated more consistent associations with allergic respiratory symptoms than grass pollen counts.

Reference: jacionline.org/article/S0091-6749(23)01469-0/fulltext