Determination of ragweed allergen Amb a 1 distribution in aerosols using ELISA and immunogold scanning electron microscopy

Background: Ragweed as an invasive species in Europe has
become more important for allergy sufferers in the last decade.
Because pollen fractions can be found in the respirable fraction
of aerosols, they can generate severe disease progressions.
Objective: To obtain information about the concentration and
distribution of 1 of the main ragweed allergens Ambrosia
artemisiifolia 1 in the air of Vienna, PM10 and PM2.5 fine dust
filters were analyzed.
Methods: Standard fine dust filters used for air quality
monitoring were analyzed via ELISA and immunogold scanning
electron microscopy.
Results: Via ELISA it was possible to show that already at
pollen season start in August a recognizably high A
artemisiifolia 1 concentration can be found. In addition, the
allergen concentration in the air stays comparatively high after
the peak season has ended even when the pollen concentration
drops to a moderate level. The immunogold electron microscopy
investigation directly applied on filters shows that the allergen
can be found on organic as well as on mixtures of organic and
inorganic particles. A first semistatistical analysis of the labeled
particle sizes indicates that a large number of the allergen
carriers can be found within the smallest particle size range.
Nevertheless, further investigations are needed to obtain enough
particle counts for a significant statistical analysis.
Conclusions: It was possible to show that reliable results can be
obtained from ELISA and immunogold scanning electron
microscopy directly applied on filters that are used in air
quality monitoring sites. By adaptation of the used protocols, it
should be possible to obtain respective information about
further allergens.