a quantitative immunochromatography assay of whole blood samples for antigen-specific ige—a new method for point of care testing for allergens—

Background: The development of an inexpensive point-of-care testing system for antigen-specific IgE is greatly needed. We, therefore, tried to develop a quantitative enzyme immunochromatography assay system for antigen-specific IgE in fresh whole blood. Methods: Whole blood sample was mixed with a reagent containing detergent to lyse red blood cells, and the mixture was applied to an immunochromatography strip. The lysate was observed to migrate in the strip and was washed away by the substrate buffer. When the sample contained the specific IgE, the antigen-specific IgE line was clearly observed on the strip macroscopically. Results: Results were obtained 20 minutes after the application of hemolysed blood sample to immunochromatography, and these results showed positive correlation with those obtained by the AlaSTAT system, which is one of the popular assay kits for specific IgE. The results were not affected significantly by the hematocrit value of the blood sample, by the kind of anticoagulant in the blood collection tube, or by the concentration of the total IgE, provided it was lower than 20000 IU/ml. Conclusions: These results indicate that our system is applicable for point-of-care testing for antigen-specific IgE.