Olea europaea pollen counts and aeroallergen levels predict clinical symptoms in patients allergic to olive pollen

Background Allergic symptoms are commonly related to atmospheric pollen counts in sensitized allergic individuals. However, concordance between symptoms, pollen counts, and aeroallergen concentrations is not always good. Objectives To determine the correlation between olive pollen counts, aeroallergen levels, and clinical symptoms in patients with allergic asthma or rhinitis in Ciudad Real (Spain). Methods Two types of samplers were used to determine pollen exposure: a Burkard spore trap to collect pollen grains and a high-volume air sampler to collect airborne particles. A total of 366 air filters were collected. After extraction, they were analyzed by specific immunoglobulin E enzyme-linked immunosorbent assay inhibition using a serum pool containing high titers of olive-specific immunoglobulin E. Twenty olive-pollen monosensitized patients were asked to record their daily symptoms before, during, and after the olive pollen season. Results Olive pollen was detected between April 21 and June 30, 2004. Symptoms showed positive and significant correlations with pollen counts ( r = 0.700, P < .001) and aeroallergen levels ( r = 0.803, P < .001). Using a Poisson regression model, relative changes in aeroallergen concentrations and pollen counts were found to be similar and significant. Threshold levels for the induction of symptoms were 162 olive pollen grains/m3 and 22.7 ng of olive pollen allergen/m3 (equivalent to 0.9 ng/m3 of Ole e 1). Conclusions Olive aeroallergen concentrations and pollen counts are positively associated with symptoms of rhinitis and asthma in olive-allergic patients. Both data may be used in the clinical follow-up of these patients.