Figure 1.

Induction of WT1‐specific humoral immune responses by WT1 peptide vaccination. (a) Vaccination and sampling schedules during WT1 peptide immunotherapy. (b) Increased serum WT1‐235 IgG antibody levels during vaccination with WT1 peptide. Serum WT1‐235 IgG antibody levels were determined by ELISA at the indicated time points and presented as values of absorbance at 440 nm. ***p < 0.001. (c) Two‐dimensional plot of the ratio of Th1‐ to Th2‐ type WT1‐235 IgG subclasses. Serum levels of WT1‐235 IgG₁, IgG₃, and IgG₄ antibodies were measured by ELISA using subclass‐specific secondary antibodies, and the ratio of absorbance of WT1‐235 IgG₁ or IgG₃ antibody to that of WT1‐235 IgG₄ antibody for each patient sample was plotted. (d) The levels of WT1 peptide IgG antibody subclasses. Data from two representative cases (patients 17 and 21) are shown.