Prevalence of precipitating antibodies to different extracts of XXXX in a North American @entity748 population.

@entity748 @entity1 @entity54 @entity1097
This study was carried out to find the prevalence of precipitin reactions in the sera of 200 North American @entity748 subjects. Precipitins were detected by the double diffusion technique using different extracts of @entity54 , including a reference 'home produced' extract and five commercial extracts from three different suppliers. In addition, antigenicity of these extracts was assessed by crossed immunoelectrophoresis (XIE). Of the sera, 13.5% reacted to the reference extract and from 2.5 to 12% to the different commercial extracts; 22.5% of the sera reacted to at least one extract. No one serum reacted to all the extracts. Two of fifty-one (4%) nonatopic @entity1 with a negative immediate prick test to A. fumigatus, six of eighty-seven (6.9%) @entity1097 @entity1 with a negative immediate reaction to A. fumigatus, and thirty-seven of sixty two (59%) @entity1097 @entity1 with a positive immediate reaction to A. fumigatus had precipitins to at least one of the extracts used, the skin tests being performed using the A. fumigatus reference extract. The prevalence of precipitin reactions bore a strong correlation with the antigenicity of the extracts by XIE. The same reference extract was also used for specific IgE measurements (Brompton extract, Malo _ Paquin, 1979). It was found that @entity1 with precipitins had significantly (P less than 0.001) higher specific and total IgE values than @entity1 without precipitins. In the group of @entity1 with positive skin test, those with precipitins had significantly (P less than 0.05) higher specific IgE values than those without. The authors conclude that different extracts of A. fumigatus should be used to assess the presence of precipitins. The antigenicity of these extracts should also be assayed.
