Figure 4. Allergenic activity of Bet v 1.0401.

IgE binding properties of Bet v 1.0401 batches were tested by ELISA. Results are presented as mean OD values of triplicate measurements after background subtraction. Sera of 13 birch pollen-allergic individuals were tested. Data are presented as median OD405/492 units, 10^th, 25^th, 75^th, and 90^th percentiles as vertical boxes with error bars. P-values were calculated by paired-samples t-test (**P<.01) (A). Allergenic activity of Bet v 1.0401 batches was assessed in huFcεRI-transfected RBL-2H3 cells sensitized with serum IgE from birch pollen-allergic patients (n = 8). Protein concentrations (ng/ml) to obtain 50% of maximum degranulation were determined for the respective antigens. P-values were calculated by paired-samples t-test (*P<.05). In addition, protein concentrations (ng/ml) to obtain maximal mediator release was determined for the respective antigens, as indicated in the upper right corner of the figure grey bars. As negative control RBL cells were loaded with normal human serum (n = 3) and activated with the respective antigens as indicated by white bars. All data are presented as median, 10^th, 25^th, 75^th, and 90^th percentiles as vertical boxes with error bars (B).