Frequency of DCs in whole blood and marrow samples (from 10 control subjects, 20 MGUS, and 20 MM patients). (A-D) Bar graphs show mean and standard deviation of percentages (A-B) and absolute numbers (C-D) of mDCs and pDCs identified with CD11c and CD123 mAb (A,C) or with BDCA-1/BDCA-3 and BDCA-2 mAb (B,D) in differently gated cells (see Figure 1). Kruskal-Wallis analysis of variance and Mann-Whitney U test for comparisons of groups. (E) Correlation between absolute numbers of BM plasma cells and absolute numbers of both mDCs and pDCs in MGUS and MM patients. Spearman’s rank test for correlations. P values are shown only for statistically significant comparisons.