Extracts of Amaranthus spinosus (pigweed) stem and leaves with a concentration of 1:100, 1:1,000 and 1:10,000 weight by volume were tested for their allergenicity by skin testing using pollen 1:1,000 weight by volume as the standard for comparison. Of the 94 patients tested, 33 who were positive for pollen were also positive for leaves 1:100 weight by volume while 49 patients were negative for both. There was no significant difference in the allergenicity of the pollen and leaves (p <0.05) and there was a good correlation in the degree of reaction. Lower concentrations of the leaves and all concentrations of the stem showed a significant decrease in the positivity of reaction. This study serves as an initial procedural step for further fractionation and determination of the allergenic fraction of the leaves and comparing them with that of pollen.
The study aimed to prepare extracts from the stem and leaves of Amaranthus spinosus (pigweed) and to use these in the allergic subjects to determine other plant parts allergenicity compared to pollens.