Evidence of grass‐pollen allergenic activity in the smaller micronic atmospheric aerosol fraction

Abstract

In June 1988, during the grass-pollen season in Leiden, The Netherlands, outdoor airborne particulate matter was collected and separated into fractions according to aerodynamic sizes (greater than or equal to 10 microns, 4.9-10 microns, 2.7-4.9 microns, 1.3-2.7 microns, 0.6-1.3 microns, less than or equal to 0.6 microns), with a cascade impactor mounted on top of a high volume sampler. The different fractions were tested for the presence of grass-pollen allergenic activity using a RAST-inhibition assay: specific IgE-antibody-containing patient serum was applied on the particle-loaded impaction strips, and the serum was recovered by descending elution for further analysis in the RAST. Simultaneously, continuous measurements were made of the airborne grass-pollen concentration using a volumetric pollen trap. Sampling observations lasting 7-9 hr during a period with relatively high airborne grass-pollen concentrations showed reliably detectable amounts of grass-pollen allergen, not only in the first impaction stage where intact pollen were collected, but also in the lower stages collecting the smaller, paucimicronic and submicron atmospheric aerosol fraction. It is evident that this result has serious implications for the understanding of the bronchial symptoms frequently seen in hay fever patients on days with high pollen concentrations in the air.

Grass-pollen allergen carried by the smaller micronic aerosol fraction

“…Thc remaining unbound specific antibodies and (part of) the allergcn-antibody complexes were collected in the eluate (Spieksma et al 1990). …”

“…In these experiments, impaction strips of non-hydrophobic glass fibre were used. To verify the sizing efficiency of the cascade impactor, pieces of the five impaction strips were examined with a scanning electron microscope (Spieksma et al 1990). …”

“…Although it is plausible that a small number of airborne pollen grains might be capable of penetrating into the lower regions of the respiratory organs (Michel et al 1977), suggestions and evidence for airborne allergenic activity associated with particles smaller than intact pollen grains have been put forward by several authors (Solomon et al 1983, Agarwal et al 1984, Rantio-Lehtimlki et al 1986, Jensen et al 1989. Sampling i f multiple size fractions followed by immuno-assay assessment of airborne grass-pollen allergenic activity has been described only recently (Spieksma et al 1990).…”

Airborne Grass Pollen Antigens in a Grassland as Studied by Immunoblotting with Anti-Lol pI Antibody

“…The phenomenon indicates the existence of amorphous Lof p I particles not shown as morphologically intact pollen grains. There are some reports concerning the existence of amorphous airborne pollen antigens during the grass season (Schumacher et al 1988, Spieksma et al 1990, the ragweed season (Aganval et al 1984), the birch season (Rantio-Lehtimaki et al 1987) and Japanese Cedar season (Takahashi et al 1991).…”

Variability in protein content of pollen of Castor bean (Ricinus communis) before and after exposure to the air pollutants SO and NO

“…It is hypothesized that the loss of proteins from pollen exposed to pollutants in the atmosphere could be deposited on the ultra-fine, (v1mm) respirable dust particles thus rendering them allergenic (Spieksma et al 1990, Schä ppi et al 1996.…”